Spring实现类私有方法的几个问题(亲测通用解决方案)

public class BeanInvokeUtil {
 
  public class InvokeParams {
 
// 方法名称（私有）
    private String methodName;
 
// 参数列表类型数组
    private Class<?>[] paramTypes;
// 调用的对象
    private Object object;
 
// 参数列表数组（如果不为null，需要和paramTypes对应）
    private Object[] args;
 
    public InvokeParams() {
      super();
    }
 
    public InvokeParams(Object object, String methodName, Class<?>[] paramTypes, Object[] args) {
      this.methodName = methodName;
      this.paramTypes = paramTypes;
      this.object = object;
      this.args = args;
    }
 
    public String getMethodName() {
      return methodName;
    }
 
    public void setMethodName(String methodName) {
      this.methodName = methodName;
    }
 
    public Class<?>[] getParamTypes() {
      return paramTypes;
    }
 
    public void setParamTypes(Class<?>[] paramTypes) {
      this.paramTypes = paramTypes;
    }
 
    public Object getObject() {
      return object;
    }
 
    public void setObject(Object object) {
      this.object = object;
    }
 
    public Object[] getArgs() {
      return args;
    }
 
    public void setArgs(Object[] args) {
      this.args = args;
    }
  }
 
  public static Object invokePrivateMethod(InvokeParams invokeParams) throws InvocationTargetException, IllegalAccessException {
    // 参数检查
    checkParams(invokeParams);
    // 调用
    return doInvoke(invokeParams);
  }
 
  private static Object doInvoke(InvokeParams invokeParams) throws InvocationTargetException, IllegalAccessException {
    Object object = invokeParams.getObject();
    String methodName = invokeParams.getMethodName();
    Class<?>[] paramTypes = invokeParams.getParamTypes();
    Object[] args = invokeParams.getArgs();
 
    Method method;
    if (paramTypes == null) {
      method = BeanUtils.findDeclaredMethod(object.getClass(), methodName);
    } else {
      method = BeanUtils.findDeclaredMethod(object.getClass(), methodName, paramTypes);
    }
    method.setAccessible(true);
    if (args == null) {
      return method.invoke(object);
    }
    return method.invoke(object, args);
 
  }
 
  private static void checkParams(InvokeParams invokeParams) {
    Object object = invokeParams.getObject();
    if (object == null) {
      throw new IllegalArgumentException("object can not be null");
    }
    String methodName = invokeParams.getMethodName();
    if (StringUtils.isEmpty(methodName)) {
      throw new IllegalArgumentException("methodName can not be empty");
    }
 
    // 参数类型数组和参数数组要对应
    Class<?>[] paramTypes = invokeParams.getParamTypes();
    Object[] args = invokeParams.getArgs();
 
    boolean illegal = true;
    if (paramTypes == null && args != null) {
      illegal = false;
    }
    if (args == null && paramTypes != null) {
      illegal = false;
    }
    if (paramTypes != null && args != null && paramTypes.length != args.length) {
      illegal = false;
    }
    if (!illegal) {
      throw new IllegalArgumentException("paramTypes length != args length");
    }
  }
}

@Autowired private XXXService xxxService;

BeanInvokeUtil.invokePrivateMethod(new BeanInvokeUtil()
            .new InvokeParams(xxxService, "somePrivateMethod", null, null));

public class Test {
  @Autowired
  ServiceImpl serviceImpl;

  @Test
  public void test() throws Exception {
  Class<?> clazz = Class.forName("ServiceImpl");
  Method method = clazz.getDeclaredMethod("MethodA");
  method.setAccessible(true);
  Object target = ReflectionUtil.getTarget(serviceImpl);
  // 注意，这里不能直接用serviceImpl，因为它已经被spring管理，
  // 变成serviceImpl真实实例的代理类，而代理类中并没有私有方法，所以需要先获取它的真实实例
  method.invoke(target);
  }
}

public class ReflectionUtil {
  /**
   * 获取spring 代理对象的真实实例
   * @param proxy 代理对象
   * @return
   * @throws Exception
   */
  public static Object getTarget(Object proxy) throws Exception {
    if(!AopUtils.isAopProxy(proxy)) {
      return proxy;//不是代理对象
    }

    if(AopUtils.isJdkDynamicProxy(proxy)) {
      return getJdkDynamicProxyTargetObject(proxy);
    } else { //cglib
      return getCglibProxyTargetObject(proxy);
    }
  }

  private static Object getCglibProxyTargetObject(Object proxy) throws Exception {
    Field h = proxy.getClass().getDeclaredField("CGLIB$CALLBACK_0");
    h.setAccessible(true);
    Object dynamicAdvisedInterceptor = h.get(proxy);
    Field advised = dynamicAdvisedInterceptor.getClass().getDeclaredField("advised");
    advised.setAccessible(true);
    Object target = ((AdvisedSupport)advised.get(dynamicAdvisedInterceptor)).getTargetSource().getTarget();
    return target;
  }

  private static Object getJdkDynamicProxyTargetObject(Object proxy) throws Exception {
    Field h = proxy.getClass().getSuperclass().getDeclaredField("h");
    h.setAccessible(true);
    AopProxy aopProxy = (AopProxy) h.get(proxy);
    Field advised = aopProxy.getClass().getDeclaredField("advised");
    advised.setAccessible(true);
    Object target = ((AdvisedSupport)advised.get(aopProxy)).getTargetSource().getTarget();
    return target;
  }
}