jdk/src/share/classes/com/sun/naming/internal/VersionHelper12.java
changeset 2 90ce3da70b43
child 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/com/sun/naming/internal/VersionHelper12.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,256 @@
+/*
+ * Copyright 1999-2006 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package com.sun.naming.internal;
+
+import java.io.InputStream;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URLClassLoader;
+import java.net.URL;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+import java.security.PrivilegedActionException;
+import java.security.PrivilegedExceptionAction;
+import java.util.Enumeration;
+import java.util.Hashtable;
+import java.util.NoSuchElementException;
+import java.util.Properties;
+
+import javax.naming.*;
+
+/**
+ * VersionHelper was used by JNDI to accommodate differences between
+ * JDK 1.1.x and the Java 2 platform. As this is no longer necessary
+ * since JNDI's inclusion in the platform, this class currently
+ * serves as a set of utilities for performing system-level things,
+ * such as class-loading and reading system properties.
+ *
+ * @author Rosanna Lee
+ * @author Scott Seligman
+ */
+
+final class VersionHelper12 extends VersionHelper {
+
+    private boolean getSystemPropsFailed = false;
+
+    VersionHelper12() {} // Disallow external from creating one of these.
+
+    public Class loadClass(String className) throws ClassNotFoundException {
+        ClassLoader cl = getContextClassLoader();
+        return Class.forName(className, true, cl);
+    }
+
+    /**
+      * Package private.
+      */
+    Class loadClass(String className, ClassLoader cl)
+        throws ClassNotFoundException {
+        return Class.forName(className, true, cl);
+    }
+
+    /**
+     * @param className A non-null fully qualified class name.
+     * @param codebase A non-null, space-separated list of URL strings.
+     */
+    public Class loadClass(String className, String codebase)
+        throws ClassNotFoundException, MalformedURLException {
+        ClassLoader cl;
+
+        ClassLoader parent = getContextClassLoader();
+        cl = URLClassLoader.newInstance(getUrlArray(codebase), parent);
+
+        return Class.forName(className, true, cl);
+    }
+
+    String getJndiProperty(final int i) {
+        return (String) AccessController.doPrivileged(
+            new PrivilegedAction() {
+                public Object run() {
+                    try {
+                        return System.getProperty(PROPS[i]);
+                    } catch (SecurityException e) {
+                        return null;
+                    }
+                }
+            }
+        );
+    }
+
+    String[] getJndiProperties() {
+        if (getSystemPropsFailed) {
+            return null;        // after one failure, don't bother trying again
+        }
+        Properties sysProps = (Properties) AccessController.doPrivileged(
+            new PrivilegedAction() {
+                public Object run() {
+                    try {
+                        return System.getProperties();
+                    } catch (SecurityException e) {
+                        getSystemPropsFailed = true;
+                        return null;
+                    }
+                }
+            }
+        );
+        if (sysProps == null) {
+            return null;
+        }
+        String[] jProps = new String[PROPS.length];
+        for (int i = 0; i < PROPS.length; i++) {
+            jProps[i] = sysProps.getProperty(PROPS[i]);
+        }
+        return jProps;
+    }
+
+    InputStream getResourceAsStream(final Class c, final String name) {
+        return (InputStream) AccessController.doPrivileged(
+            new PrivilegedAction() {
+                public Object run() {
+                    return c.getResourceAsStream(name);
+                }
+            }
+        );
+    }
+
+    InputStream getJavaHomeLibStream(final String filename) {
+        return (InputStream) AccessController.doPrivileged(
+            new PrivilegedAction() {
+                public Object run() {
+                    try {
+                        String javahome = System.getProperty("java.home");
+                        if (javahome == null) {
+                            return null;
+                        }
+                        String pathname = javahome + java.io.File.separator +
+                            "lib" + java.io.File.separator + filename;
+                        return new java.io.FileInputStream(pathname);
+                    } catch (Exception e) {
+                        return null;
+                    }
+                }
+            }
+        );
+    }
+
+    NamingEnumeration getResources(final ClassLoader cl, final String name)
+            throws IOException
+    {
+        Enumeration urls;
+        try {
+            urls = (Enumeration) AccessController.doPrivileged(
+                new PrivilegedExceptionAction() {
+                    public Object run() throws IOException {
+                        return (cl == null)
+                            ? ClassLoader.getSystemResources(name)
+                            : cl.getResources(name);
+                    }
+                }
+            );
+        } catch (PrivilegedActionException e) {
+            throw (IOException)e.getException();
+        }
+        return new InputStreamEnumeration(urls);
+    }
+
+    ClassLoader getContextClassLoader() {
+        return (ClassLoader) AccessController.doPrivileged(
+            new PrivilegedAction() {
+                public Object run() {
+                    return Thread.currentThread().getContextClassLoader();
+                }
+            }
+        );
+    }
+
+
+    /**
+     * Given an enumeration of URLs, an instance of this class represents
+     * an enumeration of their InputStreams.  Each operation on the URL
+     * enumeration is performed within a doPrivileged block.
+     * This is used to enumerate the resources under a foreign codebase.
+     * This class is not MT-safe.
+     */
+    class InputStreamEnumeration implements NamingEnumeration {
+
+        private final Enumeration urls;
+
+        private Object nextElement = null;
+
+        InputStreamEnumeration(Enumeration urls) {
+            this.urls = urls;
+        }
+
+        /*
+         * Returns the next InputStream, or null if there are no more.
+         * An InputStream that cannot be opened is skipped.
+         */
+        private Object getNextElement() {
+            return AccessController.doPrivileged(
+                new PrivilegedAction() {
+                    public Object run() {
+                        while (urls.hasMoreElements()) {
+                            try {
+                                return ((URL)urls.nextElement()).openStream();
+                            } catch (IOException e) {
+                                // skip this URL
+                            }
+                        }
+                        return null;
+                    }
+                }
+            );
+        }
+
+        public boolean hasMore() {
+            if (nextElement != null) {
+                return true;
+            }
+            nextElement = getNextElement();
+            return (nextElement != null);
+        }
+
+        public boolean hasMoreElements() {
+            return hasMore();
+        }
+
+        public Object next() {
+            if (hasMore()) {
+                Object res = nextElement;
+                nextElement = null;
+                return res;
+            } else {
+                throw new NoSuchElementException();
+            }
+        }
+
+        public Object nextElement() {
+            return next();
+        }
+
+        public void close() {
+        }
+    }
+}