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/*
* Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Oracle nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* This source code is provided to illustrate the usage of a given feature
* or technique and has been deliberately simplified. Additional steps
* required for a production-quality application, such as security checks,
* input validation and proper error handling, might not be present in
* this sample code.
*/
/*
*/
import javax.management.*;
import javax.management.remote.*;
import java.io.IOException;
import java.net.MalformedURLException;
/**
* This VerboseGC class demonstrates the capability to get
* the garbage collection statistics and memory usage remotely.
*/
public class VerboseGC {
private MBeanServerConnection server;
private JMXConnector jmxc;
public VerboseGC(String hostname, int port) {
System.out.println("Connecting to " + hostname + ":" + port);
// Create an RMI connector client and connect it to
// the RMI connector server
String urlPath = "/jndi/rmi://" + hostname + ":" + port + "/jmxrmi";
connect(urlPath);
}
public void dump(long interval, long samples) {
try {
PrintGCStat pstat = new PrintGCStat(server);
for (int i = 0; i < samples; i++) {
pstat.printVerboseGc();
try {
Thread.sleep(interval);
} catch (InterruptedException e) {
System.exit(1);
}
}
} catch (IOException e) {
System.err.println("\nCommunication error: " + e.getMessage());
System.exit(1);
}
}
/**
* Connect to a JMX agent of a given URL.
*/
private void connect(String urlPath) {
try {
JMXServiceURL url = new JMXServiceURL("rmi", "", 0, urlPath);
this.jmxc = JMXConnectorFactory.connect(url);
this.server = jmxc.getMBeanServerConnection();
} catch (MalformedURLException e) {
// should not reach here
} catch (IOException e) {
System.err.println("\nCommunication error: " + e.getMessage());
System.exit(1);
}
}
public static void main(String[] args) {
if (args.length < 1) {
usage();
}
String hostname = "";
int port = -1;
long interval = 5000; // default is 5 second interval
long mins = 5;
for (String arg: args) {
if (arg.startsWith("-")) {
if (arg.equals("-h") ||
arg.equals("-help") ||
arg.equals("-?")) {
usage();
} else if (arg.startsWith("-interval=")) {
try {
interval = Integer.parseInt(arg.substring(10)) * 1000;
} catch (NumberFormatException ex) {
usage();
}
} else if (arg.startsWith("-duration=")) {
try {
mins = Integer.parseInt(arg.substring(10));
} catch (NumberFormatException ex) {
usage();
}
} else {
// Unknown switch
System.err.println("Unrecognized option: " + arg);
usage();
}
} else {
String[] arg2 = arg.split(":");
if (arg2.length != 2) {
usage();
}
hostname = arg2[0];
try {
port = Integer.parseInt(arg2[1]);
} catch (NumberFormatException x) {
usage();
}
if (port < 0) {
usage();
}
}
}
// get full thread dump and perform deadlock detection
VerboseGC vgc = new VerboseGC(hostname, port);
long samples = (mins * 60 * 1000) / interval;
vgc.dump(interval, samples);
}
private static void usage() {
System.out.print("Usage: java VerboseGC <hostname>:<port> ");
System.out.println(" [-interval=seconds] [-duration=minutes]");
}
}
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