JSP开发之Spring方法注入之替换方法实现

public interface MethodReplacer {

 /
  Reimplement the given method.
  @param obj the instance we're reimplementing the method for
  @param method the method to reimplement
  @param args arguments to the method
  @return return value for the method
 /
 Object reimplement(Object obj, Method method, Object[] args) throws Throwable;

}

public class BeanA {

 public int add(int a, int b) {
 return a+b;
 }
 
}
 <bean id="beanA" class=".app.BeanA"/>

public class BeanAReplacer implements MethodReplacer {

 /
  @param obj 对应目标对象，即beanA
  @param method 对应目标方法，即add
  @param args 对应目标参数，即a和b
 /
 public Object reimplement(Object obj, Method method, Object[] args)
  throws Throwable {
 Integer a = (Integer)args[0];
 Integer b = (Integer)args[1];
 if (a.equals(b)) {
  return a  b;
 } else {
  return a + b;
 }
 }

}

<bean id="beanAReplacer" class=".app.BeanAReplacer"/>
 <bean id="beanA" class=".app.BeanA">
 <replaced-method name="add" replacer="beanAReplacer"/>
 </bean>

<bean id="beanAReplacer" class=".app.BeanAReplacer"/>
 <bean id="beanA" class=".app.BeanA">
 <replaced-method name="add" replacer="beanAReplacer">
  <arg-type match="int"/>
  <arg-type match="int"/>
 </replaced-method>
 </bean>