如何注入已运行Java程序，并获取其中的信息

Question

缘起：
已运行的一Java程序，由于某些原因，该程序的配置文件（.properties文件）被删除了。
现在需要恢复此配置文件，以便此程序可以多次重启。现在已经不敢重启程序了。
（已另外想办法欲从文件系统进行恢复，未果。）问题：
如何才能获取此程序内存中的信息，将配置信息抓出来呢？尝试过如下的方法，但由于程序运行在linux系统中，所以未成功。
http://www.blogjava.net/javacap/archive/2007/01/04/91735.html
http://bbs.chinaunix.net/thread-880524-1-1.html请问各位有何良策，不胜感激！

Answer 1

attach api
这个库不包含在jre的库中，在jdk的lib里tools.jar

Answer 2

谢谢！
请问有什么工具推荐吗？系统是Red Hat Enterprise Linux 5.x

Answer 3

看看这个帖子：
http://topic.csdn.net/t/20030922/21/2288646.html

Answer 4

代码注入？这个不好搞吧，JVM进程的中的数据结构很难解析吧

Answer 5

http://www.zeuux.org/blog/content/3430/package com.tools;import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.Set;import javax.management.AttributeNotFoundException;
import javax.management.InstanceNotFoundException;
import javax.management.IntrospectionException;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanException;
import javax.management.MBeanInfo;
import javax.management.MBeanOperationInfo;
import javax.management.MBeanServerConnection;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectInstance;
import javax.management.ObjectName;
import javax.management.ReflectionException;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;import sun.management.ConnectorAddressLink;import com.sun.tools.attach.AgentInitializationException;
import com.sun.tools.attach.AgentLoadException;
import com.sun.tools.attach.AttachNotSupportedException;
import com.sun.tools.attach.VirtualMachine;
public class AttachDemo
{
    public void test(String pid) throws NumberFormatException, IOException, AttachNotSupportedException, AgentLoadException, AgentInitializationException, MalformedObjectNameException, NullPointerException, InstanceNotFoundException, IntrospectionException, ReflectionException, AttributeNotFoundException, MBeanException
    {    
        String domainName = "Erosa";
    
        String localJmxAddress = ConnectorAddressLink.importFrom(Integer.valueOf(pid).intValue());
        if (localJmxAddress == null) 
        {
          VirtualMachine vm = VirtualMachine.attach(pid);
          String connectorAddress = vm.getAgentProperties().getProperty("com.sun.management.jmxremote.localConnectorAddress");
          if (connectorAddress == null) 
          {
            String agent = vm.getSystemProperties().getProperty("java.home") + File.separator + "lib" + File.separator + "management-agent.jar";
            vm.loadAgent(agent);
            connectorAddress = vm.getAgentProperties().getProperty("com.sun.management.jmxremote.localConnectorAddress");
          }
          if (connectorAddress == null) 
          {
            System.err.println("Failed to get Local JMX Address by Pid. Exit Without Further Processing.");
            System.exit(-1);
          }
          localJmxAddress = connectorAddress;
        }
    
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        JMXConnector connector = JMXConnectorFactory.newJMXConnector(new JMXServiceURL(localJmxAddress), null);
        try 
        {
          connector.connect();
          MBeanServerConnection connection = connector.getMBeanServerConnection();
          Set<ObjectInstance> set = connection.queryMBeans(new ObjectName(domainName + ":*"), null);
          for (ObjectInstance ins : set) 
          {
            System.out.println("==================================================================");
    
            ObjectName name = ins.getObjectName();
    
            System.out.println("MBean : " + name.toString());
    
            MBeanInfo beaninfo = connection.getMBeanInfo(name);
            MBeanAttributeInfo[] attributes = beaninfo.getAttributes();
            System.out.println("-----------Attributes------------");
            for (MBeanAttributeInfo attr : attributes) 
            {
              System.out.println(attr.getName() + ": " + connection.getAttribute(name, attr.getName()));
            }
            MBeanOperationInfo[] operations = beaninfo.getOperations();
            System.out.println("-----------Operations------------");
            for (MBeanOperationInfo operation : operations) 
            {
              System.out.println("operation: " + operation.getName() + " " + Arrays.toString(operation.getSignature()));
              if (operation.getName().startsWith("dump")) 
              {
                System.out.println(connection.invoke(name, operation.getName(), new Object[0], new String[0]));
              }
            }
          }
          System.out.println("exit jmx client.");
        }
        finally
        {
          connector.close();
          reader.close();
        }
  }
}

Answer 6

楼主可以从 那套 解析.properties文件并封装其数据的类下手,访问这些类,把访问到的数据重新写入一个properties文件...