net.sf.jiapi.agent

Class InstrumentationAgent

java.lang.Object

net.sf.jiapi.agent.InstrumentationAgent

All Implemented Interfaces:

ClassFileTransformer

public class InstrumentationAgent
extends Object
implements ClassFileTransformer

This class is an implementation of ClassFileTransformer and acts as a java-agent for jdk1.5+ virtual machines.

You can enable this agent from command line by adding -javaagent switch to command line like this:

java -javaagent:<path_to_jiapi.jar> HelloWorld

One can give configuration parameters in command line to this agent and Transformer used. Parameters are given by appending the following to -javaagent switch:

'=name1=value1,name2=value2,....'

This agent regoqnises one parameter: 'transformer=<name_of_the_transformer>. If this parameter is given, It is assumed to be a fully qualified name of a class, that extends net.sf.jiapi.agent.Transformer. If not given, net.sf.jiapi.agent.HotSpotTransformer is used.

See Also:

Transformer, HotSpotTransformer

Constructor Summary

Constructors

Constructor and Description
InstrumentationAgent(Properties p, Instrumentation i, Transformer transformer)

Method Summary

Modifier and Type	Method and Description
static void	agentmain(String agentArgs, Instrumentation inst) This method will be called after VM startup.
Properties	getAgentArgs() Gets the agent arguments that has been passed during premain(...)
Instrumentation	getInstrumentation() Gets the Instrumentation associated with this ClassFileTransformer.
static void	premain(String agentArgs, Instrumentation instrumentation) This method will be called after VM initialization.
byte[]	transform(ClassLoader cl, String className, Class<?> classBeingRedefined, ProtectionDomain pd, byte[] classFileBuffer)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

InstrumentationAgent

public InstrumentationAgent(Properties p,
                            Instrumentation i,
                            Transformer transformer)

Method Detail

agentmain

public static void agentmain(String agentArgs,
                             Instrumentation inst)

This method will be called after VM startup. We propagate the call to premain(...)

Parameters:

agentArgs - args

inst - Instrumentation

premain

public static void premain(String agentArgs,
                           Instrumentation instrumentation)

This method will be called after VM initialization.

Parameters:

agentArgs - args

instrumentation - Instrumnetation

transform

public byte[] transform(ClassLoader cl,
                        String className,
                        Class<?> classBeingRedefined,
                        ProtectionDomain pd,
                        byte[] classFileBuffer)

Specified by:

transform in interface ClassFileTransformer

getInstrumentation

public Instrumentation getInstrumentation()

Gets the Instrumentation associated with this ClassFileTransformer.

Returns:

Instrumentation

getAgentArgs

public Properties getAgentArgs()

Gets the agent arguments that has been passed during premain(...) or agentmain(...) methods. Arguments has been stored into Properties for ease of access

Returns:

Properties