import sun.management.counter.perf.PerfInstrumentation; //导入依赖的package包/类
/**
 * Imports the connector address from the instrument buffer
 * of the specified Java virtual machine.
 *
 * @param vmid an identifier that uniquely identifies a local Java virtual
 * machine, or <code>0</code> to indicate the current Java virtual machine.
 *
 * @return the value of the connector address, or <code>null</code> if the
 * target VM has not exported a connector address.
 *
 * @throws IOException An I/O error occurred while trying to acquire the
 * instrumentation buffer.
 */
public static String importFrom(int vmid) throws IOException {
    Perf perf = Perf.getPerf();
    ByteBuffer bb;
    try {
        bb = perf.attach(vmid, "r");
    } catch (IllegalArgumentException iae) {
        throw new IOException(iae.getMessage());
    }
    List<Counter> counters =
            new PerfInstrumentation(bb).findByPattern(CONNECTOR_ADDRESS_COUNTER);
    Iterator<Counter> i = counters.iterator();
    if (i.hasNext()) {
        Counter c = i.next();
        return (String) c.getValue();
    } else {
        return null;
    }
}
 

import sun.management.counter.perf.PerfInstrumentation; //导入依赖的package包/类
/**
 * Imports the remote connector address and associated
 * configuration properties from the instrument buffer
 * of the specified Java virtual machine.
 *
 * @param vmid an identifier that uniquely identifies a local Java virtual
 * machine, or <code>0</code> to indicate the current Java virtual machine.
 *
 * @return a map containing the remote connector's properties, or an empty
 * map if the target VM has not exported the remote connector's properties.
 *
 * @throws IOException An I/O error occurred while trying to acquire the
 * instrumentation buffer.
 */
public static Map<String, String> importRemoteFrom(int vmid) throws IOException {
    Perf perf = Perf.getPerf();
    ByteBuffer bb;
    try {
        bb = perf.attach(vmid, "r");
    } catch (IllegalArgumentException iae) {
        throw new IOException(iae.getMessage());
    }
    List<Counter> counters = new PerfInstrumentation(bb).getAllCounters();
    Map<String, String> properties = new HashMap<>();
    for (Counter c : counters) {
        String name =  c.getName();
        if (name.startsWith(REMOTE_CONNECTOR_COUNTER_PREFIX) &&
                !name.equals(CONNECTOR_ADDRESS_COUNTER)) {
            properties.put(name, c.getValue().toString());
        }
    }
    return properties;
}
 

import sun.management.counter.perf.PerfInstrumentation; //导入依赖的package包/类
/**
 * Imports the connector address from the instrument buffer
 * of the specified Java virtual machine.
 *
 * @param vmid an identifier that uniquely identifies a local Java virtual
 * machine, or <code>0</code> to indicate the current Java virtual machine.
 *
 * @return the value of the connector address, or <code>null</code> if the
 * target VM has not exported a connector address.
 *
 * @throws IOException An I/O error occurred while trying to acquire the
 * instrumentation buffer.
 */
public static String importFrom(int vmid) throws IOException {
    Perf perf = Perf.getPerf();
    ByteBuffer bb;
    try {
        bb = perf.attach(vmid, "r");
    } catch (IllegalArgumentException iae) {
        throw new IOException(iae.getMessage());
    }
    List counters =
            new PerfInstrumentation(bb).findByPattern(CONNECTOR_ADDRESS_COUNTER);
    Iterator i = counters.iterator();
    if (i.hasNext()) {
        Counter c = (Counter) i.next();
        return (String) c.getValue();
    } else {
        return null;
    }
}
 

import sun.management.counter.perf.PerfInstrumentation; //导入依赖的package包/类
/**
 * Imports the remote connector address and associated
 * configuration properties from the instrument buffer
 * of the specified Java virtual machine.
 *
 * @param vmid an identifier that uniquely identifies a local Java virtual
 * machine, or <code>0</code> to indicate the current Java virtual machine.
 *
 * @return a map containing the remote connector's properties, or an empty
 * map if the target VM has not exported the remote connector's properties.
 *
 * @throws IOException An I/O error occurred while trying to acquire the
 * instrumentation buffer.
 */
public static Map<String, String> importRemoteFrom(int vmid) throws IOException {
    Perf perf = Perf.getPerf();
    ByteBuffer bb;
    try {
        bb = perf.attach(vmid, "r");
    } catch (IllegalArgumentException iae) {
        throw new IOException(iae.getMessage());
    }
    List counters = new PerfInstrumentation(bb).getAllCounters();
    Map<String, String> properties = new HashMap<String, String>();
    for (Object c : counters) {
        String name = ((Counter) c).getName();
        if (name.startsWith(REMOTE_CONNECTOR_COUNTER_PREFIX) &&
                !name.equals(CONNECTOR_ADDRESS_COUNTER)) {
            properties.put(name, ((Counter) c).getValue().toString());
        }
    }
    return properties;
}