1 /*

     2  * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 package jdk.internal.vm;

    26 

    27 import java.io.ByteArrayOutputStream;

    28 import java.io.IOException;

    29 import java.util.Properties;

    30 import java.util.Set;

    31 import java.util.jar.JarFile;

    32 import java.util.jar.Manifest;

    33 import java.util.jar.Attributes;

    34 

    35 /*

    36  * Support class used by JVMTI and VM attach mechanism.

    37  */

    38 public class VMSupport {

    39 

    40     private static Properties agentProps = null;

    41     /**

    42      * Returns the agent properties.

    43      */

    44     public static synchronized Properties getAgentProperties() {

    45         if (agentProps == null) {

    46             agentProps = new Properties();

    47             initAgentProperties(agentProps);

    48         }

    49         return agentProps;

    50     }

    51     private static native Properties initAgentProperties(Properties props);

    52 

    53     /**

    54      * Write the given properties list to a byte array and return it. Properties with

    55      * a key or value that is not a String is filtered out. The stream written to the byte

    56      * array is ISO 8859-1 encoded.

    57      */

    58     private static byte[] serializePropertiesToByteArray(Properties p) throws IOException {

    59         ByteArrayOutputStream out = new ByteArrayOutputStream(4096);

    60 

    61         Properties props = new Properties();

    62 

    63         // stringPropertyNames() returns a snapshot of the property keys

    64         Set<String> keyset = p.stringPropertyNames();

    65         for (String key : keyset) {

    66             String value = p.getProperty(key);

    67             props.put(key, value);

    68         }

    69 

    70         props.store(out, null);

    71         return out.toByteArray();

    72     }

    73 

    74     public static byte[] serializePropertiesToByteArray() throws IOException {

    75         return serializePropertiesToByteArray(System.getProperties());

    76     }

    77 

    78     public static byte[] serializeAgentPropertiesToByteArray() throws IOException {

    79         return serializePropertiesToByteArray(getAgentProperties());

    80     }

    81 

    82     /*

    83      * Returns true if the given JAR file has the Class-Path attribute in the

    84      * main section of the JAR manifest. Throws RuntimeException if the given

    85      * path is not a JAR file or some other error occurs.

    86      */

    87     public static boolean isClassPathAttributePresent(String path) {

    88         try {

    89             Manifest man = (new JarFile(path)).getManifest();

    90             if (man != null) {

    91                 if (man.getMainAttributes().getValue(Attributes.Name.CLASS_PATH) != null) {

    92                     return true;

    93                 }

    94             }

    95             return false;

    96         } catch (IOException ioe) {

    97             throw new RuntimeException(ioe.getMessage());

    98         }

    99     }

   100 

   101     /*

   102      * Return the temporary directory that the VM uses for the attach

   103      * and perf data files.

   104      *

   105      * It is important that this directory is well-known and the

   106      * same for all VM instances. It cannot be affected by configuration

   107      * variables such as java.io.tmpdir.

   108      */

   109     public static native String getVMTemporaryDirectory();

   110 }