AsmBackedClassGenerator.java 文件源码

public void addConstructor(Constructor<?> constructor) throws Exception {
    List<Type> paramTypes = new ArrayList<Type>();
    for (Class<?> paramType : constructor.getParameterTypes()) {
        paramTypes.add(Type.getType(paramType));
    }
    String methodDescriptor = Type.getMethodDescriptor(VOID_TYPE, paramTypes.toArray(EMPTY_TYPES));

    MethodVisitor methodVisitor = visitor.visitMethod(Opcodes.ACC_PUBLIC, "<init>", methodDescriptor, signature(constructor), EMPTY_STRINGS);

    for (Annotation annotation : constructor.getDeclaredAnnotations()) {
        if (annotation.annotationType().getAnnotation(Inherited.class) != null) {
            continue;
        }
        Retention retention = annotation.annotationType().getAnnotation(Retention.class);
        AnnotationVisitor annotationVisitor = methodVisitor.visitAnnotation(Type.getType(annotation.annotationType()).getDescriptor(), retention != null && retention.value() == RetentionPolicy.RUNTIME);
        annotationVisitor.visitEnd();
    }

    methodVisitor.visitCode();

    // this.super(p0 .. pn)
    methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
    for (int i = 0; i < constructor.getParameterTypes().length; i++) {
        methodVisitor.visitVarInsn(Type.getType(constructor.getParameterTypes()[i]).getOpcode(Opcodes.ILOAD), i + 1);
    }
    methodVisitor.visitMethodInsn(Opcodes.INVOKESPECIAL, superclassType.getInternalName(), "<init>", methodDescriptor, false);

    methodVisitor.visitInsn(Opcodes.RETURN);
    methodVisitor.visitMaxs(0, 0);
    methodVisitor.visitEnd();
}