mockit.internal.classGeneration.ImplementationClass Maven / Gradle / Ivy
/*
* Copyright (c) 2006 Rogério Liesenfeld
* This file is subject to the terms of the MIT license (see LICENSE.txt).
*/
package mockit.internal.classGeneration;
import java.lang.reflect.Type;
import javax.annotation.*;
import mockit.external.asm.*;
import mockit.internal.*;
import mockit.internal.util.*;
import static mockit.external.asm.ClassReader.*;
/**
* Allows the creation of new implementation classes for interfaces and abstract classes.
*/
public abstract class ImplementationClass
{
@Nonnull protected final Class sourceClass;
@Nonnull protected String generatedClassName;
@Nullable private byte[] generatedBytecode;
protected ImplementationClass(@Nonnull Type mockedType) { this(Utilities.getClassType(mockedType)); }
protected ImplementationClass(@Nonnull Class mockedClass)
{
this(mockedClass, GeneratedClasses.getNameForGeneratedClass(mockedClass, null));
}
protected ImplementationClass(@Nonnull Class sourceClass, @Nonnull String desiredClassName)
{
this.sourceClass = sourceClass;
generatedClassName = desiredClassName;
}
@Nonnull
public final Class generateClass()
{
ClassReader classReader = ClassFile.createReaderOrGetFromCache(sourceClass);
ClassVisitor modifier = createMethodBodyGenerator(classReader);
classReader.accept(modifier, SKIP_FRAMES);
return defineNewClass(modifier);
}
@Nonnull
protected abstract ClassVisitor createMethodBodyGenerator(@Nonnull ClassReader typeReader);
@Nonnull
private Class defineNewClass(@Nonnull ClassVisitor modifier)
{
final ClassLoader parentLoader = ClassLoad.getClassLoaderWithAccess(sourceClass);
final byte[] modifiedClassfile = modifier.toByteArray();
try {
@SuppressWarnings("unchecked")
Class generatedClass = (Class) new ClassLoader(parentLoader) {
@Override
protected Class findClass(String name) throws ClassNotFoundException
{
if (!name.equals(generatedClassName)) {
return parentLoader.loadClass(name);
}
return defineClass(name, modifiedClassfile, 0, modifiedClassfile.length);
}
}.findClass(generatedClassName);
generatedBytecode = modifiedClassfile;
return generatedClass;
}
catch (ClassNotFoundException e) {
throw new RuntimeException("Unable to define class: " + generatedClassName, e);
}
}
@Nullable
public final byte[] getGeneratedBytecode() { return generatedBytecode; }
}