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    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 sun.misc;
   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   }

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