java - CGLib是否修改类的所有实例

Question

如果我如下实现一些 MethodInterceptor:

public class HashCodeAlwaysZeroMethodInterceptor implements MethodInterceptor {

  public Object intercept(Object object, Method method, Object[] args,
    MethodProxy methodProxy) throws Throwable {

    if ("hashCode".equals(method.getName())) {

      return 0;
    }

    return methodProxy.invokeSuper(object, args);
  }
}

Object proxy = Enhancer.create(
  Object.class,
  new HashCodeAlwaysZeroMethodInterceptor());

现在是否增强了 Object 的每个实例？即:如果我做类似的事情:

class foo { foo(){} }
foo myfoo = new foo();
int hash = myfoo.hashCode();
System.io.println(hash); //Prints 0

它真的会打印 0 吗？

Answer 1

来自 API 文档

创建

public static Factory create(java.lang.Class type,
                             Callback callback)

Helper method to create an intercepted object. For finer control over the generated instance, use a new instance of Enhancer instead of this static method.

Parameters:
    type - class to extend or interface to implement
    callback - the callback to use for all methods

从文档看来你的问题的答案是肯定的