## org.springframework.instrument.classloading
Class InstrumentationLoadTimeWeaver

    java.lang.Object
      org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver

All Implemented Interfaces:
  LoadTimeWeaver

    public class InstrumentationLoadTimeWeaver

extends Object
implements LoadTimeWeaver

`LoadTimeWeaver` relying on VM `Instrumentation`.

Start the JVM specifying the Java agent to be used, like as follows:

`-javaagent:path/to/org.springframework.instrument.jar`

where `org.springframework.instrument.jar` is a JAR file containing the `InstrumentationSavingAgent` class, as shipped with Spring.

In Eclipse, for example, set the "Run configuration"'s JVM args to be of the form:

`-javaagent:${project_loc}/lib/org.springframework.instrument.jar`

Since:
  2.0
Author:
  Rod Johnson, Juergen Hoeller
See Also:
  `InstrumentationSavingAgent`

Constructor Summary
`InstrumentationLoadTimeWeaver()` Create a new InstrumentationLoadTimeWeaver for the default ClassLoader.
`InstrumentationLoadTimeWeaver(ClassLoader classLoader)` Create a new InstrumentationLoadTimeWeaver for the given ClassLoader.

Method Summary
`void` `addTransformer(ClassFileTransformer transformer)` Add a `ClassFileTransformer` to be applied by this `LoadTimeWeaver`.
`ClassLoader` `getInstrumentableClassLoader()` We have the ability to weave the current class loader when starting the JVM in this way, so the instrumentable class loader will always be the current loader.
`ClassLoader` `getThrowawayClassLoader()` This implementation always returns a `SimpleThrowawayClassLoader`.
`static boolean` `isInstrumentationAvailable()` Check whether an Instrumentation instance is available for the current VM.
`void` `removeTransformers()` Remove all registered transformers, in inverse order of registration.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### InstrumentationLoadTimeWeaver

    public InstrumentationLoadTimeWeaver()

  Create a new InstrumentationLoadTimeWeaver for the default ClassLoader.

### InstrumentationLoadTimeWeaver

    public InstrumentationLoadTimeWeaver(ClassLoader classLoader)

  Create a new InstrumentationLoadTimeWeaver for the given ClassLoader.

  Parameters:
    `classLoader` - the ClassLoader that registered transformers are supposed to apply to

Method Detail

### addTransformer

    public void addTransformer(ClassFileTransformer transformer)

  Description copied from interface: `LoadTimeWeaver`
  Add a `ClassFileTransformer` to be applied by this `LoadTimeWeaver`.

  Specified by:
    `addTransformer` in interface `LoadTimeWeaver`
  Parameters:
    `transformer` - the `ClassFileTransformer` to add

### getInstrumentableClassLoader

    public ClassLoader getInstrumentableClassLoader()

  We have the ability to weave the current class loader when starting the JVM in this way, so the instrumentable class loader will always be the current loader.

  Specified by:
    `getInstrumentableClassLoader` in interface `LoadTimeWeaver`
  Returns:
    the `ClassLoader` which will expose instrumented classes according to the registered transformers

### getThrowawayClassLoader

    public ClassLoader getThrowawayClassLoader()

  This implementation always returns a `SimpleThrowawayClassLoader`.

  Specified by:
    `getThrowawayClassLoader` in interface `LoadTimeWeaver`
  Returns:
    a temporary throwaway `ClassLoader`; should return a new instance for each call, with no existing state

### removeTransformers

    public void removeTransformers()

  Remove all registered transformers, in inverse order of registration.

### isInstrumentationAvailable

    public static boolean isInstrumentationAvailable()

  Check whether an Instrumentation instance is available for the current VM.

  See Also:
    `getInstrumentation()`