Java命令显示进程

Question

嗨，我想用 java 代码将 jboss 7 显示为进程信息和数据库 session 信息...我尝试这个代码:

Process p = Runtime.getRuntime().exec
                    (System.getenv("windir") +"\\system32\\"+"tasklist.exe");

和这段代码:

Process p = Runtime.getRuntime().exec
                    ("C:\\Users\\user\\Downloads\\PSTools\\pslist.exe -s 2");

它运行良好，但仅适用于 Windows 操作系统。所以我想要一个可以在每个操作系统上运行的java代码，而不仅仅是在windows或linux上......你能帮我吗？谢谢大家。

Answer 1

在同一主机上查找 java 进程相当简单(稍后列出一些注意事项)。连接到它们的 JMX 接口(interface)也是可以实现的。至于跟踪数据库 session ，从概念上讲，您可以获取所需的任何数据，只要它是通过可访问的 MBean 发布的。

该过程需要使用 Java Attach API 。这是一个简单的示例，我将列出在我的主机上运行的所有 JVM，尝试附加到它们并列出它们的堆使用情况。

首先，这是导入:

import java.io.File;
import java.lang.management.ManagementFactory;
import java.lang.management.MemoryUsage;
import java.util.List;

import javax.management.MBeanServerConnection;
import javax.management.ObjectName;
import javax.management.openmbean.CompositeData;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;

import com.sun.tools.attach.VirtualMachine;
import com.sun.tools.attach.VirtualMachineDescriptor;

com.sun.tools.attach 类位于 JVM 的 tools.jar 中。代码如下:

public class AttachAPIExample {

    /**
     * Uses the attach API to locate all JVMs accessible on this machine.
     * @param args None
     */
    public static void main(String[] args) {
        // Get my PID
        final String MYPID = ManagementFactory.getRuntimeMXBean().getName().split("@")[0];
        log("Scanning for JVMs...");
        // List all the Virtual Machine Descriptors
        List<VirtualMachineDescriptor> descriptors = VirtualMachine.list(); 
        for(VirtualMachineDescriptor vmd: descriptors) {
            VirtualMachine vm = null;
            // Do this in a catch block in case we run into a JVM that is not the same "bit" as we are
            try {
                vm = vmd.provider().attachVirtualMachine(vmd.id());
                String display = vmd.displayName().trim().isEmpty() ? "Unknown" : vmd.displayName();
                log("JVM%sPID: %s Display: %s", vmd.id().equals(MYPID) ? " (Me) " : " ", vmd.id(), display);
                String connectorAddress = vm.getAgentProperties().getProperty("com.sun.management.jmxremote.localConnectorAddress", null);
                if(connectorAddress!=null) {
                    log("\tConnector Found Installed at [%s]", connectorAddress);
                } else {
                    String javaHome = vm.getSystemProperties().getProperty("java.home");
                    File agentJarFile = new File(javaHome + File.separator + "lib" + File.separator + "management-agent.jar");
                    if(agentJarFile.exists()) {
                        log("I think we can find this JVM's management agent here: [%s]", agentJarFile.toString());
                        vm.loadAgent(agentJarFile.getAbsolutePath());
                        connectorAddress = vm.getAgentProperties().getProperty("com.sun.management.jmxremote.localConnectorAddress", null);
                        log("\tConnector Installed at [%s]", connectorAddress);
                    } else {
                        log("Cannot find the agent jar for JVM [%s] at [%s]", vmd.id(), javaHome);
                    }
                }
                // Now lets try and connect and read some MBean values
                if(connectorAddress!=null) {
                    log("Attaching to JVM [%s]...", vmd.id());
                    JMXServiceURL jmxUrl = new JMXServiceURL(connectorAddress);
                    JMXConnector connector = null;
                    try {
                        connector = JMXConnectorFactory.connect(jmxUrl);
                        MBeanServerConnection conn = connector.getMBeanServerConnection();
                        MemoryUsage heap = MemoryUsage.from((CompositeData)conn.getAttribute(new ObjectName(ManagementFactory.MEMORY_MXBEAN_NAME), "HeapMemoryUsage"));
                        log("Heap Usage: %s", heap);
                    } finally {
                        if(connector!=null) {
                            try { connector.close(); } catch (Exception ex) {/* No Op */}
                        }
                    }
                }
            } catch (Exception ex) {
                /* No Op */
            } finally {
                if(vm!=null) try { vm.detach(); } catch (Exception ex) {/* No Op */}
                             log("======================================");
            }
        }

    }

    public static void log(String fmt, Object...args) {
        System.out.println(String.format(fmt, args));
    }

}

这是一些示例输出:

Scanning for JVMs...
JVM PID: 27928 Display: sun.tools.jconsole.JConsole
    Connector Found Installed at [service:jmx:rmi://127.0.0.1/stub/rO0ABXNyAC5qYXZheC5tYW5hZ2VtZW50LnJlbW90ZS5ybWkuUk1JU2VydmVySW1wbF9TdHViAAAAAAAAAAICAAB4cgAaamF2YS5ybWkuc2VydmVyLlJlbW90ZVN0dWLp/tzJi+FlGgIAAHhyABxqYXZhLnJtaS5zZXJ2ZXIuUmVtb3RlT2JqZWN002G0kQxhMx4DAAB4cHc3AAtVbmljYXN0UmVmMgAADDEwLjEyLjExNC4zNwAA9bhcC21U1Z9PMPLlR/0AAAFAxsF5moACAHg=]
Attaching to JVM [27928]...
Heap Usage: init = 8388608(8192K) used = 40242696(39299K) committed = 44236800(43200K) max = 5726666752(5592448K)
======================================
JVM PID: 25028 Display: org.jboss.Main -c ecseu -b 0.0.0.0
I think we can find this JVM's management agent here: [c:\java\jdk1.6.0_30\jre\lib\management-agent.jar]
    Connector Installed at [service:jmx:rmi://127.0.0.1/stub/rO0ABXNyAC5qYXZheC5tYW5hZ2VtZW50LnJlbW90ZS5ybWkuUk1JU2VydmVySW1wbF9TdHViAAAAAAAAAAICAAB4cgAaamF2YS5ybWkuc2VydmVyLlJlbW90ZVN0dWLp/tzJi+FlGgIAAHhyABxqYXZhLnJtaS5zZXJ2ZXIuUmVtb3RlT2JqZWN002G0kQxhMx4DAAB4cHc4AAtVbmljYXN0UmVmMgAADVBQLVdLLU5XSEktMDEAAPjJTzYbxtjrUKazaPTEAAABQMuKX+6ABAB4]
Attaching to JVM [25028]...
Heap Usage: init = 1073741824(1048576K) used = 173876432(169801K) committed = 982581248(959552K) max = 982581248(959552K)
======================================

注意事项

1. JMV 只能附加到同位 JVM(即 32 位到 32 位、64 位到 64 位)
2. 启动附加的操作系统用户必须具有访问其他处理的操作系统授权。所以同一个用户，没问题。其他用户...您应该是 root。
3. 当在不同的 JVM 供应商实现中使用时，附加 API 会产生不同的结果。 IE。如果是 Sun/Oracle/OpenJDK，你可能就不错了。如果是这些，并且您正在尝试连接到 IBM JVM(反之亦然)，那么我不知道会发生什么，尽管 JRockit 在这方面似乎相当友好。
4. 我不知道所有注意事项。