//$Id: InstrumentTask.java 10209 2006-08-03 20:35:26Z [email protected] $
package org.hibernate.tool.instrument.cglib;
import org.hibernate.bytecode.util.BasicClassFilter;
import org.hibernate.bytecode.util.ClassDescriptor;
import org.hibernate.bytecode.cglib.BytecodeProviderImpl;
import org.hibernate.bytecode.ClassTransformer;
import org.hibernate.tool.instrument.BasicInstrumentationTask;
import org.objectweb.asm.ClassReader;
import java.io.ByteArrayInputStream;
import net.sf.cglib.core.ClassNameReader;
import net.sf.cglib.transform.impl.InterceptFieldEnabled;
/**
* An Ant task for instrumenting persistent classes in order to enable
* field-level interception using CGLIB.
* <p/>
* In order to use this task, typically you would define a a taskdef
* similiar to:<pre>
* <taskdef name="instrument" classname="org.hibernate.tool.instrument.cglib.InstrumentTask">
* <classpath refid="lib.class.path"/>
* </taskdef>
* </pre>
* where <tt>lib.class.path</tt> is an ANT path reference containing all the
* required Hibernate and CGLIB libraries.
* <p/>
* And then use it like:<pre>
* <instrument verbose="true">
* <fileset dir="${testclasses.dir}/org/hibernate/test">
* <include name="yadda/yadda/**"/>
* ...
* </fileset>
* </instrument>
* </pre>
* where the nested ANT fileset includes the class you would like to have
* instrumented.
* <p/>
* Optionally you can chose to enable "Extended Instrumentation" if desired
* by specifying the extended attriubute on the task:<pre>
* <instrument verbose="true" extended="true">
* ...
* </instrument>
* </pre>
* See the Hibernate manual regarding this option.
*
* @author Gavin King
* @author Steve Ebersole
*/
public class InstrumentTask extends BasicInstrumentationTask {
private static final BasicClassFilter CLASS_FILTER = new BasicClassFilter();
private final BytecodeProviderImpl provider = new BytecodeProviderImpl();
protected ClassDescriptor getClassDescriptor(byte[] byecode) throws Exception {
return new CustomClassDescriptor( byecode );
}
protected ClassTransformer getClassTransformer(ClassDescriptor descriptor) {
if ( descriptor.isInstrumented() ) {
logger.verbose( "class [" + descriptor.getName() + "] already instrumented" );
return null;
}
else {
return provider.getTransformer( CLASS_FILTER, new CustomFieldFilter( descriptor ) );
}
}
private static class CustomClassDescriptor implements ClassDescriptor {
private final byte[] bytecode;
private final String name;
private final boolean isInstrumented;
public CustomClassDescriptor(byte[] bytecode) throws Exception {
this.bytecode = bytecode;
ClassReader reader = new ClassReader( new ByteArrayInputStream( bytecode ) );
String[] names = ClassNameReader.getClassInfo( reader );
this.name = names[0];
boolean instrumented = false;
for ( int i = 1; i < names.length; i++ ) {
if ( InterceptFieldEnabled.class.getName().equals( names[i] ) ) {
instrumented = true;
break;
}
}
this.isInstrumented = instrumented;
}
public String getName() {
return name;
}
public boolean isInstrumented() {
return isInstrumented;
}
public byte[] getBytes() {
return bytecode;
}
}
}
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