8218628: Add detailed message to NullPointerException describing what is null.
/*
* Copyright (c) 1995, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.lang;
import java.lang.module.ModuleDescriptor;
import java.lang.module.ModuleDescriptor.Exports;
import java.lang.module.ModuleDescriptor.Opens;
import java.lang.reflect.Member;
import java.io.FileDescriptor;
import java.io.File;
import java.io.FilePermission;
import java.net.InetAddress;
import java.net.SocketPermission;
import java.security.AccessControlContext;
import java.security.AccessController;
import java.security.Permission;
import java.security.PrivilegedAction;
import java.security.Security;
import java.security.SecurityPermission;
import java.util.HashSet;
import java.util.Map;
import java.util.Objects;
import java.util.PropertyPermission;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import jdk.internal.module.ModuleLoaderMap;
import jdk.internal.reflect.CallerSensitive;
import sun.security.util.SecurityConstants;
/**
* The security manager is a class that allows
* applications to implement a security policy. It allows an
* application to determine, before performing a possibly unsafe or
* sensitive operation, what the operation is and whether
* it is being attempted in a security context that allows the
* operation to be performed. The
* application can allow or disallow the operation.
* <p>
* The <code>SecurityManager</code> class contains many methods with
* names that begin with the word <code>check</code>. These methods
* are called by various methods in the Java libraries before those
* methods perform certain potentially sensitive operations. The
* invocation of such a <code>check</code> method typically looks like this:
* <blockquote><pre>
* SecurityManager security = System.getSecurityManager();
* if (security != null) {
* security.check<i>XXX</i>(argument, . . . );
* }
* </pre></blockquote>
* <p>
* The security manager is thereby given an opportunity to prevent
* completion of the operation by throwing an exception. A security
* manager routine simply returns if the operation is permitted, but
* throws a <code>SecurityException</code> if the operation is not
* permitted.
* <p>
* Environments using a security manager will typically set the security
* manager at startup. In the JDK implementation, this is done by setting
* the system property {@code java.security.manager} on the command line to
* the class name of the security manager. It can also be set to the empty
* String ("") or the special token "{@code default}" to use the
* default {@code java.lang.SecurityManager}. If a class name is specified,
* it must be {@code java.lang.SecurityManager} or a public subclass and have
* a public no-arg constructor. The class is loaded by the
* {@linkplain ClassLoader#getSystemClassLoader() built-in system class loader}
* if it is not {@code java.lang.SecurityManager}. If the
* {@code java.security.manager} system property is not set, the default value
* is {@code null}, which means a security manager will not be set at startup.
* <p>
* The Java run-time may also allow, but is not required to allow, the security
* manager to be set dynamically by invoking the
* {@link System#setSecurityManager(SecurityManager) setSecurityManager} method.
* In the JDK implementation, if the Java virtual machine is started with
* the {@code java.security.manager} system property set to the special token
* "{@code disallow}" then a security manager will not be set at startup and
* cannot be set dynamically (the
* {@link System#setSecurityManager(SecurityManager) setSecurityManager}
* method will throw an {@code UnsupportedOperationException}). If the
* {@code java.security.manager} system property is not set or is set to the
* special token "{@code allow}", then a security manager will not be set at
* startup but can be set dynamically. Finally, if the
* {@code java.security.manager} system property is set to the class name of
* the security manager, or to the empty String ("") or the special token
* "{@code default}", then a security manager is set at startup (as described
* previously) and can also be subsequently replaced (or disabled) dynamically
* (subject to the policy of the currently installed security manager). The
* following table illustrates the behavior of the JDK implementation for the
* different settings of the {@code java.security.manager} system property:
* <table class="striped">
* <caption style="display:none">property value,
* the SecurityManager set at startup,
* can dynamically set a SecurityManager
* </caption>
* <thead>
* <tr>
* <th scope="col">Property Value</th>
* <th scope="col">The SecurityManager set at startup</th>
* <th scope="col">System.setSecurityManager run-time behavior</th>
* </tr>
* </thead>
* <tbody>
*
* <tr>
* <th scope="row">null</th>
* <td>None</td>
* <td>Success or throws {@code SecurityException} if not permitted by
* the currently installed security manager</td>
* </tr>
*
* <tr>
* <th scope="row">empty String ("")</th>
* <td>{@code java.lang.SecurityManager}</td>
* <td>Success or throws {@code SecurityException} if not permitted by
* the currently installed security manager</td>
* </tr>
*
* <tr>
* <th scope="row">"default"</th>
* <td>{@code java.lang.SecurityManager}</td>
* <td>Success or throws {@code SecurityException} if not permitted by
* the currently installed security manager</td>
* </tr>
*
* <tr>
* <th scope="row">"disallow"</th>
* <td>None</td>
* <td>Always throws {@code UnsupportedOperationException}</td>
* </tr>
*
* <tr>
* <th scope="row">"allow"</th>
* <td>None</td>
* <td>Success or throws {@code SecurityException} if not permitted by
* the currently installed security manager</td>
* </tr>
*
* <tr>
* <th scope="row">a class name</th>
* <td>the named class</td>
* <td>Success or throws {@code SecurityException} if not permitted by
* the currently installed security manager</td>
* </tr>
*
* </tbody>
* </table>
* <p> A future release of the JDK may change the default value of the
* {@code java.security.manager} system property to "{@code disallow}".
* <p>
* The current security manager is returned by the
* {@link System#getSecurityManager() getSecurityManager} method.
* <p>
* The special method
* {@link SecurityManager#checkPermission(java.security.Permission)}
* determines whether an access request indicated by a specified
* permission should be granted or denied. The
* default implementation calls
*
* <pre>
* AccessController.checkPermission(perm);
* </pre>
*
* <p>
* If a requested access is allowed,
* <code>checkPermission</code> returns quietly. If denied, a
* <code>SecurityException</code> is thrown.
* <p>
* The default implementation of each of the other
* <code>check</code> methods in <code>SecurityManager</code> is to
* call the <code>SecurityManager checkPermission</code> method
* to determine if the calling thread has permission to perform the requested
* operation.
* <p>
* Note that the <code>checkPermission</code> method with
* just a single permission argument always performs security checks
* within the context of the currently executing thread.
* Sometimes a security check that should be made within a given context
* will actually need to be done from within a
* <i>different</i> context (for example, from within a worker thread).
* The {@link SecurityManager#getSecurityContext getSecurityContext} method
* and the {@link SecurityManager#checkPermission(java.security.Permission,
* java.lang.Object) checkPermission}
* method that includes a context argument are provided
* for this situation. The
* <code>getSecurityContext</code> method returns a "snapshot"
* of the current calling context. (The default implementation
* returns an AccessControlContext object.) A sample call is
* the following:
*
* <pre>
* Object context = null;
* SecurityManager sm = System.getSecurityManager();
* if (sm != null) context = sm.getSecurityContext();
* </pre>
*
* <p>
* The <code>checkPermission</code> method
* that takes a context object in addition to a permission
* makes access decisions based on that context,
* rather than on that of the current execution thread.
* Code within a different context can thus call that method,
* passing the permission and the
* previously-saved context object. A sample call, using the
* SecurityManager <code>sm</code> obtained as in the previous example,
* is the following:
*
* <pre>
* if (sm != null) sm.checkPermission(permission, context);
* </pre>
*
* <p>Permissions fall into these categories: File, Socket, Net,
* Security, Runtime, Property, AWT, Reflect, and Serializable.
* The classes managing these various
* permission categories are <code>java.io.FilePermission</code>,
* <code>java.net.SocketPermission</code>,
* <code>java.net.NetPermission</code>,
* <code>java.security.SecurityPermission</code>,
* <code>java.lang.RuntimePermission</code>,
* <code>java.util.PropertyPermission</code>,
* <code>java.awt.AWTPermission</code>,
* <code>java.lang.reflect.ReflectPermission</code>, and
* <code>java.io.SerializablePermission</code>.
*
* <p>All but the first two (FilePermission and SocketPermission) are
* subclasses of <code>java.security.BasicPermission</code>, which itself
* is an abstract subclass of the
* top-level class for permissions, which is
* <code>java.security.Permission</code>. BasicPermission defines the
* functionality needed for all permissions that contain a name
* that follows the hierarchical property naming convention
* (for example, "exitVM", "setFactory", "queuePrintJob", etc).
* An asterisk
* may appear at the end of the name, following a ".", or by itself, to
* signify a wildcard match. For example: "a.*" or "*" is valid,
* "*a" or "a*b" is not valid.
*
* <p>FilePermission and SocketPermission are subclasses of the
* top-level class for permissions
* (<code>java.security.Permission</code>). Classes like these
* that have a more complicated name syntax than that used by
* BasicPermission subclass directly from Permission rather than from
* BasicPermission. For example,
* for a <code>java.io.FilePermission</code> object, the permission name is
* the path name of a file (or directory).
*
* <p>Some of the permission classes have an "actions" list that tells
* the actions that are permitted for the object. For example,
* for a <code>java.io.FilePermission</code> object, the actions list
* (such as "read, write") specifies which actions are granted for the
* specified file (or for files in the specified directory).
*
* <p>Other permission classes are for "named" permissions -
* ones that contain a name but no actions list; you either have the
* named permission or you don't.
*
* <p>Note: There is also a <code>java.security.AllPermission</code>
* permission that implies all permissions. It exists to simplify the work
* of system administrators who might need to perform multiple
* tasks that require all (or numerous) permissions.
* <p>
* See {@extLink security_guide_permissions
* Permissions in the Java Development Kit (JDK)}
* for permission-related information.
* This document includes a table listing the various SecurityManager
* <code>check</code> methods and the permission(s) the default
* implementation of each such method requires.
* It also contains a table of the methods
* that require permissions, and for each such method tells
* which permission it requires.
*
* @author Arthur van Hoff
* @author Roland Schemers
*
* @see java.lang.ClassLoader
* @see java.lang.SecurityException
* @see java.lang.System#getSecurityManager() getSecurityManager
* @see java.lang.System#setSecurityManager(java.lang.SecurityManager)
* setSecurityManager
* @see java.security.AccessController AccessController
* @see java.security.AccessControlContext AccessControlContext
* @see java.security.AccessControlException AccessControlException
* @see java.security.Permission
* @see java.security.BasicPermission
* @see java.io.FilePermission
* @see java.net.SocketPermission
* @see java.util.PropertyPermission
* @see java.lang.RuntimePermission
* @see java.security.Policy Policy
* @see java.security.SecurityPermission SecurityPermission
* @see java.security.ProtectionDomain
*
* @since 1.0
*/
public class SecurityManager {
/*
* Have we been initialized. Effective against finalizer attacks.
*/
private boolean initialized = false;
/**
* Constructs a new <code>SecurityManager</code>.
*
* <p> If there is a security manager already installed, this method first
* calls the security manager's <code>checkPermission</code> method
* with the <code>RuntimePermission("createSecurityManager")</code>
* permission to ensure the calling thread has permission to create a new
* security manager.
* This may result in throwing a <code>SecurityException</code>.
*
* @exception java.lang.SecurityException if a security manager already
* exists and its <code>checkPermission</code> method
* doesn't allow creation of a new security manager.
* @see java.lang.System#getSecurityManager()
* @see #checkPermission(java.security.Permission) checkPermission
* @see java.lang.RuntimePermission
*/
public SecurityManager() {
synchronized(SecurityManager.class) {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
// ask the currently installed security manager if we
// can create a new one.
sm.checkPermission(new RuntimePermission
("createSecurityManager"));
}
initialized = true;
}
}
/**
* Returns the current execution stack as an array of classes.
* <p>
* The length of the array is the number of methods on the execution
* stack. The element at index <code>0</code> is the class of the
* currently executing method, the element at index <code>1</code> is
* the class of that method's caller, and so on.
*
* @return the execution stack.
*/
protected native Class<?>[] getClassContext();
/**
* Creates an object that encapsulates the current execution
* environment. The result of this method is used, for example, by the
* three-argument <code>checkConnect</code> method and by the
* two-argument <code>checkRead</code> method.
* These methods are needed because a trusted method may be called
* on to read a file or open a socket on behalf of another method.
* The trusted method needs to determine if the other (possibly
* untrusted) method would be allowed to perform the operation on its
* own.
* <p> The default implementation of this method is to return
* an <code>AccessControlContext</code> object.
*
* @return an implementation-dependent object that encapsulates
* sufficient information about the current execution environment
* to perform some security checks later.
* @see java.lang.SecurityManager#checkConnect(java.lang.String, int,
* java.lang.Object) checkConnect
* @see java.lang.SecurityManager#checkRead(java.lang.String,
* java.lang.Object) checkRead
* @see java.security.AccessControlContext AccessControlContext
*/
public Object getSecurityContext() {
return AccessController.getContext();
}
/**
* Throws a <code>SecurityException</code> if the requested
* access, specified by the given permission, is not permitted based
* on the security policy currently in effect.
* <p>
* This method calls <code>AccessController.checkPermission</code>
* with the given permission.
*
* @param perm the requested permission.
* @exception SecurityException if access is not permitted based on
* the current security policy.
* @exception NullPointerException if the permission argument is
* <code>null</code>.
* @since 1.2
*/
public void checkPermission(Permission perm) {
java.security.AccessController.checkPermission(perm);
}
/**
* Throws a <code>SecurityException</code> if the
* specified security context is denied access to the resource
* specified by the given permission.
* The context must be a security
* context returned by a previous call to
* <code>getSecurityContext</code> and the access control
* decision is based upon the configured security policy for
* that security context.
* <p>
* If <code>context</code> is an instance of
* <code>AccessControlContext</code> then the
* <code>AccessControlContext.checkPermission</code> method is
* invoked with the specified permission.
* <p>
* If <code>context</code> is not an instance of
* <code>AccessControlContext</code> then a
* <code>SecurityException</code> is thrown.
*
* @param perm the specified permission
* @param context a system-dependent security context.
* @exception SecurityException if the specified security context
* is not an instance of <code>AccessControlContext</code>
* (e.g., is <code>null</code>), or is denied access to the
* resource specified by the given permission.
* @exception NullPointerException if the permission argument is
* <code>null</code>.
* @see java.lang.SecurityManager#getSecurityContext()
* @see java.security.AccessControlContext#checkPermission(java.security.Permission)
* @since 1.2
*/
public void checkPermission(Permission perm, Object context) {
if (context instanceof AccessControlContext) {
((AccessControlContext)context).checkPermission(perm);
} else {
throw new SecurityException();
}
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to create a new class loader.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>RuntimePermission("createClassLoader")</code>
* permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkCreateClassLoader</code>
* at the point the overridden method would normally throw an
* exception.
*
* @exception SecurityException if the calling thread does not
* have permission
* to create a new class loader.
* @see java.lang.ClassLoader#ClassLoader()
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkCreateClassLoader() {
checkPermission(SecurityConstants.CREATE_CLASSLOADER_PERMISSION);
}
/**
* reference to the root thread group, used for the checkAccess
* methods.
*/
private static ThreadGroup rootGroup = getRootGroup();
private static ThreadGroup getRootGroup() {
ThreadGroup root = Thread.currentThread().getThreadGroup();
while (root.getParent() != null) {
root = root.getParent();
}
return root;
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to modify the thread argument.
* <p>
* This method is invoked for the current security manager by the
* <code>stop</code>, <code>suspend</code>, <code>resume</code>,
* <code>setPriority</code>, <code>setName</code>, and
* <code>setDaemon</code> methods of class <code>Thread</code>.
* <p>
* If the thread argument is a system thread (belongs to
* the thread group with a <code>null</code> parent) then
* this method calls <code>checkPermission</code> with the
* <code>RuntimePermission("modifyThread")</code> permission.
* If the thread argument is <i>not</i> a system thread,
* this method just returns silently.
* <p>
* Applications that want a stricter policy should override this
* method. If this method is overridden, the method that overrides
* it should additionally check to see if the calling thread has the
* <code>RuntimePermission("modifyThread")</code> permission, and
* if so, return silently. This is to ensure that code granted
* that permission (such as the JDK itself) is allowed to
* manipulate any thread.
* <p>
* If this method is overridden, then
* <code>super.checkAccess</code> should
* be called by the first statement in the overridden method, or the
* equivalent security check should be placed in the overridden method.
*
* @param t the thread to be checked.
* @exception SecurityException if the calling thread does not have
* permission to modify the thread.
* @exception NullPointerException if the thread argument is
* <code>null</code>.
* @see java.lang.Thread#resume() resume
* @see java.lang.Thread#setDaemon(boolean) setDaemon
* @see java.lang.Thread#setName(java.lang.String) setName
* @see java.lang.Thread#setPriority(int) setPriority
* @see java.lang.Thread#stop() stop
* @see java.lang.Thread#suspend() suspend
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkAccess(Thread t) {
if (t == null) {
throw new NullPointerException("thread can't be null");
}
if (t.getThreadGroup() == rootGroup) {
checkPermission(SecurityConstants.MODIFY_THREAD_PERMISSION);
} else {
// just return
}
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to modify the thread group argument.
* <p>
* This method is invoked for the current security manager when a
* new child thread or child thread group is created, and by the
* <code>setDaemon</code>, <code>setMaxPriority</code>,
* <code>stop</code>, <code>suspend</code>, <code>resume</code>, and
* <code>destroy</code> methods of class <code>ThreadGroup</code>.
* <p>
* If the thread group argument is the system thread group (
* has a <code>null</code> parent) then
* this method calls <code>checkPermission</code> with the
* <code>RuntimePermission("modifyThreadGroup")</code> permission.
* If the thread group argument is <i>not</i> the system thread group,
* this method just returns silently.
* <p>
* Applications that want a stricter policy should override this
* method. If this method is overridden, the method that overrides
* it should additionally check to see if the calling thread has the
* <code>RuntimePermission("modifyThreadGroup")</code> permission, and
* if so, return silently. This is to ensure that code granted
* that permission (such as the JDK itself) is allowed to
* manipulate any thread.
* <p>
* If this method is overridden, then
* <code>super.checkAccess</code> should
* be called by the first statement in the overridden method, or the
* equivalent security check should be placed in the overridden method.
*
* @param g the thread group to be checked.
* @exception SecurityException if the calling thread does not have
* permission to modify the thread group.
* @exception NullPointerException if the thread group argument is
* <code>null</code>.
* @see java.lang.ThreadGroup#destroy() destroy
* @see java.lang.ThreadGroup#resume() resume
* @see java.lang.ThreadGroup#setDaemon(boolean) setDaemon
* @see java.lang.ThreadGroup#setMaxPriority(int) setMaxPriority
* @see java.lang.ThreadGroup#stop() stop
* @see java.lang.ThreadGroup#suspend() suspend
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkAccess(ThreadGroup g) {
if (g == null) {
throw new NullPointerException("thread group can't be null");
}
if (g == rootGroup) {
checkPermission(SecurityConstants.MODIFY_THREADGROUP_PERMISSION);
} else {
// just return
}
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to cause the Java Virtual Machine to
* halt with the specified status code.
* <p>
* This method is invoked for the current security manager by the
* <code>exit</code> method of class <code>Runtime</code>. A status
* of <code>0</code> indicates success; other values indicate various
* errors.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>RuntimePermission("exitVM."+status)</code> permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkExit</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param status the exit status.
* @exception SecurityException if the calling thread does not have
* permission to halt the Java Virtual Machine with
* the specified status.
* @see java.lang.Runtime#exit(int) exit
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkExit(int status) {
checkPermission(new RuntimePermission("exitVM."+status));
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to create a subprocess.
* <p>
* This method is invoked for the current security manager by the
* <code>exec</code> methods of class <code>Runtime</code>.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>FilePermission(cmd,"execute")</code> permission
* if cmd is an absolute path, otherwise it calls
* <code>checkPermission</code> with
* <code>FilePermission("<<ALL FILES>>","execute")</code>.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkExec</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param cmd the specified system command.
* @exception SecurityException if the calling thread does not have
* permission to create a subprocess.
* @exception NullPointerException if the <code>cmd</code> argument is
* <code>null</code>.
* @see java.lang.Runtime#exec(java.lang.String)
* @see java.lang.Runtime#exec(java.lang.String, java.lang.String[])
* @see java.lang.Runtime#exec(java.lang.String[])
* @see java.lang.Runtime#exec(java.lang.String[], java.lang.String[])
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkExec(String cmd) {
File f = new File(cmd);
if (f.isAbsolute()) {
checkPermission(new FilePermission(cmd,
SecurityConstants.FILE_EXECUTE_ACTION));
} else {
checkPermission(new FilePermission("<<ALL FILES>>",
SecurityConstants.FILE_EXECUTE_ACTION));
}
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to dynamic link the library code
* specified by the string argument file. The argument is either a
* simple library name or a complete filename.
* <p>
* This method is invoked for the current security manager by
* methods <code>load</code> and <code>loadLibrary</code> of class
* <code>Runtime</code>.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>RuntimePermission("loadLibrary."+lib)</code> permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkLink</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param lib the name of the library.
* @exception SecurityException if the calling thread does not have
* permission to dynamically link the library.
* @exception NullPointerException if the <code>lib</code> argument is
* <code>null</code>.
* @see java.lang.Runtime#load(java.lang.String)
* @see java.lang.Runtime#loadLibrary(java.lang.String)
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkLink(String lib) {
if (lib == null) {
throw new NullPointerException("library can't be null");
}
checkPermission(new RuntimePermission("loadLibrary."+lib));
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to read from the specified file
* descriptor.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>RuntimePermission("readFileDescriptor")</code>
* permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkRead</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param fd the system-dependent file descriptor.
* @exception SecurityException if the calling thread does not have
* permission to access the specified file descriptor.
* @exception NullPointerException if the file descriptor argument is
* <code>null</code>.
* @see java.io.FileDescriptor
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkRead(FileDescriptor fd) {
if (fd == null) {
throw new NullPointerException("file descriptor can't be null");
}
checkPermission(new RuntimePermission("readFileDescriptor"));
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to read the file specified by the
* string argument.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>FilePermission(file,"read")</code> permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkRead</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param file the system-dependent file name.
* @exception SecurityException if the calling thread does not have
* permission to access the specified file.
* @exception NullPointerException if the <code>file</code> argument is
* <code>null</code>.
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkRead(String file) {
checkPermission(new FilePermission(file,
SecurityConstants.FILE_READ_ACTION));
}
/**
* Throws a <code>SecurityException</code> if the
* specified security context is not allowed to read the file
* specified by the string argument. The context must be a security
* context returned by a previous call to
* <code>getSecurityContext</code>.
* <p> If <code>context</code> is an instance of
* <code>AccessControlContext</code> then the
* <code>AccessControlContext.checkPermission</code> method will
* be invoked with the <code>FilePermission(file,"read")</code> permission.
* <p> If <code>context</code> is not an instance of
* <code>AccessControlContext</code> then a
* <code>SecurityException</code> is thrown.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkRead</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param file the system-dependent filename.
* @param context a system-dependent security context.
* @exception SecurityException if the specified security context
* is not an instance of <code>AccessControlContext</code>
* (e.g., is <code>null</code>), or does not have permission
* to read the specified file.
* @exception NullPointerException if the <code>file</code> argument is
* <code>null</code>.
* @see java.lang.SecurityManager#getSecurityContext()
* @see java.security.AccessControlContext#checkPermission(java.security.Permission)
*/
public void checkRead(String file, Object context) {
checkPermission(
new FilePermission(file, SecurityConstants.FILE_READ_ACTION),
context);
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to write to the specified file
* descriptor.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>RuntimePermission("writeFileDescriptor")</code>
* permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkWrite</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param fd the system-dependent file descriptor.
* @exception SecurityException if the calling thread does not have
* permission to access the specified file descriptor.
* @exception NullPointerException if the file descriptor argument is
* <code>null</code>.
* @see java.io.FileDescriptor
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkWrite(FileDescriptor fd) {
if (fd == null) {
throw new NullPointerException("file descriptor can't be null");
}
checkPermission(new RuntimePermission("writeFileDescriptor"));
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to write to the file specified by
* the string argument.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>FilePermission(file,"write")</code> permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkWrite</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param file the system-dependent filename.
* @exception SecurityException if the calling thread does not
* have permission to access the specified file.
* @exception NullPointerException if the <code>file</code> argument is
* <code>null</code>.
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkWrite(String file) {
checkPermission(new FilePermission(file,
SecurityConstants.FILE_WRITE_ACTION));
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to delete the specified file.
* <p>
* This method is invoked for the current security manager by the
* <code>delete</code> method of class <code>File</code>.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>FilePermission(file,"delete")</code> permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkDelete</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param file the system-dependent filename.
* @exception SecurityException if the calling thread does not
* have permission to delete the file.
* @exception NullPointerException if the <code>file</code> argument is
* <code>null</code>.
* @see java.io.File#delete()
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkDelete(String file) {
checkPermission(new FilePermission(file,
SecurityConstants.FILE_DELETE_ACTION));
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to open a socket connection to the
* specified host and port number.
* <p>
* A port number of <code>-1</code> indicates that the calling
* method is attempting to determine the IP address of the specified
* host name.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>SocketPermission(host+":"+port,"connect")</code> permission if
* the port is not equal to -1. If the port is equal to -1, then
* it calls <code>checkPermission</code> with the
* <code>SocketPermission(host,"resolve")</code> permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkConnect</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param host the host name port to connect to.
* @param port the protocol port to connect to.
* @exception SecurityException if the calling thread does not have
* permission to open a socket connection to the specified
* <code>host</code> and <code>port</code>.
* @exception NullPointerException if the <code>host</code> argument is
* <code>null</code>.
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkConnect(String host, int port) {
if (host == null) {
throw new NullPointerException("host can't be null");
}
if (!host.startsWith("[") && host.indexOf(':') != -1) {
host = "[" + host + "]";
}
if (port == -1) {
checkPermission(new SocketPermission(host,
SecurityConstants.SOCKET_RESOLVE_ACTION));
} else {
checkPermission(new SocketPermission(host+":"+port,
SecurityConstants.SOCKET_CONNECT_ACTION));
}
}
/**
* Throws a <code>SecurityException</code> if the
* specified security context is not allowed to open a socket
* connection to the specified host and port number.
* <p>
* A port number of <code>-1</code> indicates that the calling
* method is attempting to determine the IP address of the specified
* host name.
* <p> If <code>context</code> is not an instance of
* <code>AccessControlContext</code> then a
* <code>SecurityException</code> is thrown.
* <p>
* Otherwise, the port number is checked. If it is not equal
* to -1, the <code>context</code>'s <code>checkPermission</code>
* method is called with a
* <code>SocketPermission(host+":"+port,"connect")</code> permission.
* If the port is equal to -1, then
* the <code>context</code>'s <code>checkPermission</code> method
* is called with a
* <code>SocketPermission(host,"resolve")</code> permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkConnect</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param host the host name port to connect to.
* @param port the protocol port to connect to.
* @param context a system-dependent security context.
* @exception SecurityException if the specified security context
* is not an instance of <code>AccessControlContext</code>
* (e.g., is <code>null</code>), or does not have permission
* to open a socket connection to the specified
* <code>host</code> and <code>port</code>.
* @exception NullPointerException if the <code>host</code> argument is
* <code>null</code>.
* @see java.lang.SecurityManager#getSecurityContext()
* @see java.security.AccessControlContext#checkPermission(java.security.Permission)
*/
public void checkConnect(String host, int port, Object context) {
if (host == null) {
throw new NullPointerException("host can't be null");
}
if (!host.startsWith("[") && host.indexOf(':') != -1) {
host = "[" + host + "]";
}
if (port == -1)
checkPermission(new SocketPermission(host,
SecurityConstants.SOCKET_RESOLVE_ACTION),
context);
else
checkPermission(new SocketPermission(host+":"+port,
SecurityConstants.SOCKET_CONNECT_ACTION),
context);
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to wait for a connection request on
* the specified local port number.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>SocketPermission("localhost:"+port,"listen")</code>.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkListen</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param port the local port.
* @exception SecurityException if the calling thread does not have
* permission to listen on the specified port.
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkListen(int port) {
checkPermission(new SocketPermission("localhost:"+port,
SecurityConstants.SOCKET_LISTEN_ACTION));
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not permitted to accept a socket connection from
* the specified host and port number.
* <p>
* This method is invoked for the current security manager by the
* <code>accept</code> method of class <code>ServerSocket</code>.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>SocketPermission(host+":"+port,"accept")</code> permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkAccept</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param host the host name of the socket connection.
* @param port the port number of the socket connection.
* @exception SecurityException if the calling thread does not have
* permission to accept the connection.
* @exception NullPointerException if the <code>host</code> argument is
* <code>null</code>.
* @see java.net.ServerSocket#accept()
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkAccept(String host, int port) {
if (host == null) {
throw new NullPointerException("host can't be null");
}
if (!host.startsWith("[") && host.indexOf(':') != -1) {
host = "[" + host + "]";
}
checkPermission(new SocketPermission(host+":"+port,
SecurityConstants.SOCKET_ACCEPT_ACTION));
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to use
* (join/leave/send/receive) IP multicast.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>java.net.SocketPermission(maddr.getHostAddress(),
* "accept,connect")</code> permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkMulticast</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param maddr Internet group address to be used.
* @exception SecurityException if the calling thread is not allowed to
* use (join/leave/send/receive) IP multicast.
* @exception NullPointerException if the address argument is
* <code>null</code>.
* @since 1.1
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkMulticast(InetAddress maddr) {
String host = maddr.getHostAddress();
if (!host.startsWith("[") && host.indexOf(':') != -1) {
host = "[" + host + "]";
}
checkPermission(new SocketPermission(host,
SecurityConstants.SOCKET_CONNECT_ACCEPT_ACTION));
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to use
* (join/leave/send/receive) IP multicast.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>java.net.SocketPermission(maddr.getHostAddress(),
* "accept,connect")</code> permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkMulticast</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param maddr Internet group address to be used.
* @param ttl value in use, if it is multicast send.
* Note: this particular implementation does not use the ttl
* parameter.
* @exception SecurityException if the calling thread is not allowed to
* use (join/leave/send/receive) IP multicast.
* @exception NullPointerException if the address argument is
* <code>null</code>.
* @since 1.1
* @deprecated Use #checkPermission(java.security.Permission) instead
* @see #checkPermission(java.security.Permission) checkPermission
*/
@Deprecated(since="1.4")
public void checkMulticast(InetAddress maddr, byte ttl) {
String host = maddr.getHostAddress();
if (!host.startsWith("[") && host.indexOf(':') != -1) {
host = "[" + host + "]";
}
checkPermission(new SocketPermission(host,
SecurityConstants.SOCKET_CONNECT_ACCEPT_ACTION));
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to access or modify the system
* properties.
* <p>
* This method is used by the <code>getProperties</code> and
* <code>setProperties</code> methods of class <code>System</code>.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>PropertyPermission("*", "read,write")</code> permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkPropertiesAccess</code>
* at the point the overridden method would normally throw an
* exception.
*
* @exception SecurityException if the calling thread does not have
* permission to access or modify the system properties.
* @see java.lang.System#getProperties()
* @see java.lang.System#setProperties(java.util.Properties)
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkPropertiesAccess() {
checkPermission(new PropertyPermission("*",
SecurityConstants.PROPERTY_RW_ACTION));
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to access the system property with
* the specified <code>key</code> name.
* <p>
* This method is used by the <code>getProperty</code> method of
* class <code>System</code>.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>PropertyPermission(key, "read")</code> permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkPropertyAccess</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param key a system property key.
*
* @exception SecurityException if the calling thread does not have
* permission to access the specified system property.
* @exception NullPointerException if the <code>key</code> argument is
* <code>null</code>.
* @exception IllegalArgumentException if <code>key</code> is empty.
*
* @see java.lang.System#getProperty(java.lang.String)
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkPropertyAccess(String key) {
checkPermission(new PropertyPermission(key,
SecurityConstants.PROPERTY_READ_ACTION));
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to initiate a print job request.
* <p>
* This method calls
* <code>checkPermission</code> with the
* <code>RuntimePermission("queuePrintJob")</code> permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkPrintJobAccess</code>
* at the point the overridden method would normally throw an
* exception.
*
* @exception SecurityException if the calling thread does not have
* permission to initiate a print job request.
* @since 1.1
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkPrintJobAccess() {
checkPermission(new RuntimePermission("queuePrintJob"));
}
/*
* We have an initial invalid bit (initially false) for the class
* variables which tell if the cache is valid. If the underlying
* java.security.Security property changes via setProperty(), the
* Security class uses reflection to change the variable and thus
* invalidate the cache.
*
* Locking is handled by synchronization to the
* packageAccessLock/packageDefinitionLock objects. They are only
* used in this class.
*
* Note that cache invalidation as a result of the property change
* happens without using these locks, so there may be a delay between
* when a thread updates the property and when other threads updates
* the cache.
*/
private static boolean packageAccessValid = false;
private static String[] packageAccess;
private static final Object packageAccessLock = new Object();
private static boolean packageDefinitionValid = false;
private static String[] packageDefinition;
private static final Object packageDefinitionLock = new Object();
private static String[] getPackages(String p) {
String packages[] = null;
if (p != null && !p.isEmpty()) {
java.util.StringTokenizer tok =
new java.util.StringTokenizer(p, ",");
int n = tok.countTokens();
if (n > 0) {
packages = new String[n];
int i = 0;
while (tok.hasMoreElements()) {
String s = tok.nextToken().trim();
packages[i++] = s;
}
}
}
if (packages == null) {
packages = new String[0];
}
return packages;
}
// The non-exported packages in modules defined to the boot or platform
// class loaders. A non-exported package is a package that is not exported
// or is only exported to specific modules.
private static final Map<String, Boolean> nonExportedPkgs = new ConcurrentHashMap<>();
static {
addNonExportedPackages(ModuleLayer.boot());
}
/**
* Record the non-exported packages of the modules in the given layer
*/
static void addNonExportedPackages(ModuleLayer layer) {
Set<String> bootModules = ModuleLoaderMap.bootModules();
Set<String> platformModules = ModuleLoaderMap.platformModules();
layer.modules().stream()
.map(Module::getDescriptor)
.filter(md -> bootModules.contains(md.name())
|| platformModules.contains(md.name()))
.map(SecurityManager::nonExportedPkgs)
.flatMap(Set::stream)
.forEach(pn -> nonExportedPkgs.put(pn, Boolean.TRUE));
}
/**
* Called by java.security.Security
*/
static void invalidatePackageAccessCache() {
synchronized (packageAccessLock) {
packageAccessValid = false;
}
synchronized (packageDefinitionLock) {
packageDefinitionValid = false;
}
}
/**
* Returns the non-exported packages of the specified module.
*/
private static Set<String> nonExportedPkgs(ModuleDescriptor md) {
// start with all packages in the module
Set<String> pkgs = new HashSet<>(md.packages());
// remove the non-qualified exported packages
md.exports().stream()
.filter(p -> !p.isQualified())
.map(Exports::source)
.forEach(pkgs::remove);
// remove the non-qualified open packages
md.opens().stream()
.filter(p -> !p.isQualified())
.map(Opens::source)
.forEach(pkgs::remove);
return pkgs;
}
/**
* Throws a {@code SecurityException} if the calling thread is not allowed
* to access the specified package.
* <p>
* During class loading, this method may be called by the {@code loadClass}
* method of class loaders and by the Java Virtual Machine to ensure that
* the caller is allowed to access the package of the class that is
* being loaded.
* <p>
* This method checks if the specified package starts with or equals
* any of the packages in the {@code package.access} Security Property.
* An implementation may also check the package against an additional
* list of restricted packages as noted below. If the package is restricted,
* {@link #checkPermission(Permission)} is called with a
* {@code RuntimePermission("accessClassInPackage."+pkg)} permission.
* <p>
* If this method is overridden, then {@code super.checkPackageAccess}
* should be called as the first line in the overridden method.
*
* @implNote
* This implementation also restricts all non-exported packages of modules
* loaded by {@linkplain ClassLoader#getPlatformClassLoader
* the platform class loader} or its ancestors. A "non-exported package"
* refers to a package that is not exported to all modules. Specifically,
* it refers to a package that either is not exported at all by its
* containing module or is exported in a qualified fashion by its
* containing module.
*
* @param pkg the package name.
* @throws SecurityException if the calling thread does not have
* permission to access the specified package.
* @throws NullPointerException if the package name argument is
* {@code null}.
* @see java.lang.ClassLoader#loadClass(String, boolean) loadClass
* @see java.security.Security#getProperty getProperty
* @see #checkPermission(Permission) checkPermission
*/
public void checkPackageAccess(String pkg) {
Objects.requireNonNull(pkg, "package name can't be null");
// check if pkg is not exported to all modules
if (nonExportedPkgs.containsKey(pkg)) {
checkPermission(
new RuntimePermission("accessClassInPackage." + pkg));
return;
}
String[] restrictedPkgs;
synchronized (packageAccessLock) {
/*
* Do we need to update our property array?
*/
if (!packageAccessValid) {
String tmpPropertyStr =
AccessController.doPrivileged(
new PrivilegedAction<>() {
public String run() {
return Security.getProperty("package.access");
}
}
);
packageAccess = getPackages(tmpPropertyStr);
packageAccessValid = true;
}
// Using a snapshot of packageAccess -- don't care if static field
// changes afterwards; array contents won't change.
restrictedPkgs = packageAccess;
}
/*
* Traverse the list of packages, check for any matches.
*/
final int plen = pkg.length();
for (String restrictedPkg : restrictedPkgs) {
final int rlast = restrictedPkg.length() - 1;
// Optimizations:
//
// If rlast >= plen then restrictedPkg is longer than pkg by at
// least one char. This means pkg cannot start with restrictedPkg,
// since restrictedPkg will be longer than pkg.
//
// Similarly if rlast != plen, then pkg + "." cannot be the same
// as restrictedPkg, since pkg + "." will have a different length
// than restrictedPkg.
//
if (rlast < plen && pkg.startsWith(restrictedPkg) ||
// The following test is equivalent to
// restrictedPkg.equals(pkg + ".") but is noticeably more
// efficient:
rlast == plen && restrictedPkg.startsWith(pkg) &&
restrictedPkg.charAt(rlast) == '.')
{
checkPermission(
new RuntimePermission("accessClassInPackage." + pkg));
break; // No need to continue; only need to check this once
}
}
}
/**
* Throws a {@code SecurityException} if the calling thread is not
* allowed to define classes in the specified package.
* <p>
* This method is called by the {@code loadClass} method of some
* class loaders.
* <p>
* This method checks if the specified package starts with or equals
* any of the packages in the {@code package.definition} Security
* Property. An implementation may also check the package against an
* additional list of restricted packages as noted below. If the package
* is restricted, {@link #checkPermission(Permission)} is called with a
* {@code RuntimePermission("defineClassInPackage."+pkg)} permission.
* <p>
* If this method is overridden, then {@code super.checkPackageDefinition}
* should be called as the first line in the overridden method.
*
* @implNote
* This implementation also restricts all non-exported packages of modules
* loaded by {@linkplain ClassLoader#getPlatformClassLoader
* the platform class loader} or its ancestors. A "non-exported package"
* refers to a package that is not exported to all modules. Specifically,
* it refers to a package that either is not exported at all by its
* containing module or is exported in a qualified fashion by its
* containing module.
*
* @param pkg the package name.
* @throws SecurityException if the calling thread does not have
* permission to define classes in the specified package.
* @throws NullPointerException if the package name argument is
* {@code null}.
* @see java.lang.ClassLoader#loadClass(String, boolean)
* @see java.security.Security#getProperty getProperty
* @see #checkPermission(Permission) checkPermission
*/
public void checkPackageDefinition(String pkg) {
Objects.requireNonNull(pkg, "package name can't be null");
// check if pkg is not exported to all modules
if (nonExportedPkgs.containsKey(pkg)) {
checkPermission(
new RuntimePermission("defineClassInPackage." + pkg));
return;
}
String[] pkgs;
synchronized (packageDefinitionLock) {
/*
* Do we need to update our property array?
*/
if (!packageDefinitionValid) {
String tmpPropertyStr =
AccessController.doPrivileged(
new PrivilegedAction<>() {
public String run() {
return java.security.Security.getProperty(
"package.definition");
}
}
);
packageDefinition = getPackages(tmpPropertyStr);
packageDefinitionValid = true;
}
// Using a snapshot of packageDefinition -- don't care if static
// field changes afterwards; array contents won't change.
pkgs = packageDefinition;
}
/*
* Traverse the list of packages, check for any matches.
*/
for (String restrictedPkg : pkgs) {
if (pkg.startsWith(restrictedPkg) || restrictedPkg.equals(pkg + ".")) {
checkPermission(
new RuntimePermission("defineClassInPackage." + pkg));
break; // No need to continue; only need to check this once
}
}
}
/**
* Throws a <code>SecurityException</code> if the
* calling thread is not allowed to set the socket factory used by
* <code>ServerSocket</code> or <code>Socket</code>, or the stream
* handler factory used by <code>URL</code>.
* <p>
* This method calls <code>checkPermission</code> with the
* <code>RuntimePermission("setFactory")</code> permission.
* <p>
* If you override this method, then you should make a call to
* <code>super.checkSetFactory</code>
* at the point the overridden method would normally throw an
* exception.
*
* @exception SecurityException if the calling thread does not have
* permission to specify a socket factory or a stream
* handler factory.
*
* @see java.net.ServerSocket#setSocketFactory(java.net.SocketImplFactory) setSocketFactory
* @see java.net.Socket#setSocketImplFactory(java.net.SocketImplFactory) setSocketImplFactory
* @see java.net.URL#setURLStreamHandlerFactory(java.net.URLStreamHandlerFactory) setURLStreamHandlerFactory
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkSetFactory() {
checkPermission(new RuntimePermission("setFactory"));
}
/**
* Determines whether the permission with the specified permission target
* name should be granted or denied.
*
* <p> If the requested permission is allowed, this method returns
* quietly. If denied, a SecurityException is raised.
*
* <p> This method creates a <code>SecurityPermission</code> object for
* the given permission target name and calls <code>checkPermission</code>
* with it.
*
* <p> See the documentation for
* <code>{@link java.security.SecurityPermission}</code> for
* a list of possible permission target names.
*
* <p> If you override this method, then you should make a call to
* <code>super.checkSecurityAccess</code>
* at the point the overridden method would normally throw an
* exception.
*
* @param target the target name of the <code>SecurityPermission</code>.
*
* @exception SecurityException if the calling thread does not have
* permission for the requested access.
* @exception NullPointerException if <code>target</code> is null.
* @exception IllegalArgumentException if <code>target</code> is empty.
*
* @since 1.1
* @see #checkPermission(java.security.Permission) checkPermission
*/
public void checkSecurityAccess(String target) {
checkPermission(new SecurityPermission(target));
}
/**
* Returns the thread group into which to instantiate any new
* thread being created at the time this is being called.
* By default, it returns the thread group of the current
* thread. This should be overridden by a specific security
* manager to return the appropriate thread group.
*
* @return ThreadGroup that new threads are instantiated into
* @since 1.1
* @see java.lang.ThreadGroup
*/
public ThreadGroup getThreadGroup() {
return Thread.currentThread().getThreadGroup();
}
}