方法替换及在不改变原方法的情况下，使用新的方法去替换原有的方法。以下例子来演示通过XML配置的方式来替换已经存在方法。

使用技术及工具：

1.eclipse 4.4.2
2.Maven 3.1
3.JDK 1.7
4.Spring 4.3.5
5.Junit 4.12

Pom.xml配置

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<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.devnp</groupId>
  <artifactId>Spring4Demo</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>Spring4Demo</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <spring.version>4.3.5.RELEASE</spring.version>
  </properties>

  <dependencies>
  	<dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>

原方法类：

HelloService.java

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package com.devnp.SpringDemo;

public class HelloService {

	public void print(String str){
		System.out.println("Print:" + str);
	}
}

替换方法类：

MethodReplacementDemo.java

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package com.devnp.SpringDemo.method.replace;

import java.lang.reflect.Method;

import org.springframework.beans.factory.support.MethodReplacer;

public class MethodReplacementDemo implements MethodReplacer{

	public Object reimplement(Object arg0, Method arg1, Object[] arg2)
			throws Throwable {
		
		String inputStr = (String) arg2[0];
		
		System.out.println("This is replace Method Print :" + inputStr);
		
		return null;
	}

	
}

Spring XML 配置：

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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd">


	<bean id="helloService" class="com.devnp.SpringDemo.HelloService">
		<replaced-method name="print" replacer="methodReplacementDemo">
			<!-- if need, we can base on the arg type -->
			<!-- <arg-type>String</arg-type> -->
		</replaced-method>
	</bean>

	<bean id="methodReplacementDemo" class="com.devnp.SpringDemo.method.replace.MethodReplacementDemo"/>

</beans>

测试类：

MethodReplacementDemoTest.java

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package com.devnp.SpringDemo.method.replace;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.devnp.SpringDemo.HelloService;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:ApplicationContext.xml")
public class MethodReplacementDemoTest {
	
	@Autowired
	private HelloService helloService ;

	@Test
	public void test1(){
		helloService.print("Hello World");
	}
	
}

输入结果：

This is replace Method Print :Hello World

代码下载：

Spring4Demo.zip