RMIConnectorInternalMapTest.java 文件源码

public static void main(String[] args) throws Exception {
    System.out.println("---RMIConnectorInternalMapTest starting...");

    JMXConnectorServer connectorServer = null;
    JMXConnector connectorClient = null;

    try {
        MBeanServer mserver = ManagementFactory.getPlatformMBeanServer();
        JMXServiceURL serverURL = new JMXServiceURL("rmi", "localhost", 0);
        connectorServer = JMXConnectorServerFactory.newJMXConnectorServer(serverURL, null, mserver);
        connectorServer.start();

        JMXServiceURL serverAddr = connectorServer.getAddress();
        connectorClient = JMXConnectorFactory.connect(serverAddr, null);
        connectorClient.connect();

        Field rmbscMapField = RMIConnector.class.getDeclaredField("rmbscMap");
        rmbscMapField.setAccessible(true);
        Map<Subject, WeakReference<MBeanServerConnection>> map =
                (Map<Subject, WeakReference<MBeanServerConnection>>) rmbscMapField.get(connectorClient);
        if (map != null && !map.isEmpty()) { // failed
            throw new RuntimeException("RMIConnector's rmbscMap must be empty at the initial time.");
        }

        Subject delegationSubject =
                new Subject(true,
                Collections.singleton(new JMXPrincipal("delegate")),
                Collections.EMPTY_SET,
                Collections.EMPTY_SET);
        MBeanServerConnection mbsc1 =
                connectorClient.getMBeanServerConnection(delegationSubject);
        MBeanServerConnection mbsc2 =
                connectorClient.getMBeanServerConnection(delegationSubject);

        if (mbsc1 == null) {
            throw new RuntimeException("Got null connection.");
        }
        if (mbsc1 != mbsc2) {
            throw new RuntimeException("Not got same connection with a same subject.");
        }

        map = (Map<Subject, WeakReference<MBeanServerConnection>>) rmbscMapField.get(connectorClient);
        if (map == null || map.isEmpty()) { // failed
            throw new RuntimeException("RMIConnector's rmbscMap has wrong size "
                    + "after creating a delegated connection.");
        }

        delegationSubject = null;
        mbsc1 = null;
        mbsc2 = null;

        int i = 0;
        while (!map.isEmpty() && i++ < 60) {
            System.gc();
            Thread.sleep(100);
        }
        System.out.println("---GC times: " + i);

        if (!map.isEmpty()) {
            throw new RuntimeException("Failed to clean RMIConnector's rmbscMap");
        } else {
            System.out.println("---RMIConnectorInternalMapTest: PASSED!");
        }
    } finally {
        try {
            connectorClient.close();
            connectorServer.stop();
        } catch (Exception e) {
        }
    }
}