Profile with jvisualvm

http://docs.oracle.com/javase/6/docs/technotes/guides/visualvm/

http://docs.oracle.com/javase/6/docs/technotes/tools/share/jvisualvm.html

Here is how to configure Eclipse IDE launcher
http://visualvm.java.net/eclipse-launcher.html


jvisualvm is part of JDK

[dave@dave ~]$ cd /app/jdk160_29/bin
[dave@dave bin]$ ls
appletviewer   java          jcontrol    jstack        policytool   unpack200
apt            javac         jdb         jstat         rmic         wsgen
ControlPanel   javadoc       jhat        jstatd        rmid         wsimport
extcheck       javah         jinfo       jvisualvm     rmiregistry  xjc
HtmlConverter  javap         jmap        keytool       schemagen
idlj           java-rmi.cgi  jps         native2ascii  serialver
jar            javaws        jrunscript  orbd          servertool
jarsigner      jconsole      jsadebugd   pack200       tnameserv

Simple program comparing methods to create large string

package dave;

public class StringService {

    int STRING_COUNT = 10000;

    public String createString(String token) {

        String out = "";

        for (int i = 0; i < 1000; i++) {
            out += token;
        }

        return out;

    }

    public String createStringWithStringBuffer(String token) {

        StringBuffer out = new StringBuffer();

        for (int i = 0; i < STRING_COUNT; i++) {
            out.append(token);
        }

        return out.toString();
    }

    public String createStringWithStringBuilder(String token) {

        StringBuilder out = new StringBuilder();

        for (int i = 0; i < STRING_COUNT; i++) {
            out.append(token);
        }

        return out.toString();

    }

}

package dave;

public class TestProfiler {

    public static void main(String[] args) {

        String token = "dave";

        StringService stringService = new StringService();

        String result = null;

        for (int i = 0; i < 10000; i++) {

            result = stringService.createString(token);

            result = stringService.createStringWithStringBuffer(token);

            result = stringService.createStringWithStringBuilder(token);
        }

    }

}

Profiler with settings to select package


Sampler