spring的JavaConfig方式及xml配置文件混用的例子

文件结构

一、interface、bean等代码

package com.yiibai.core;

public interface IHelloWorld {
	public void printHello();
	void printHelloWorld(String msg);
}

package com.yiibai.core;

public class HelloWorldImpl implements IHelloWorld {
	private String name;

	@Override
	public void printHello() {
		// TODO 自动生成的方法存根
		System.out.println("Spring 3 : Hello ! " + name);
	}

	public void setName(String name) {
		this.name = name;
	}

	@Override
	public void printHelloWorld(String msg) {
		// TODO 自动生成的方法存根
		System.out.println("Hello : " + msg);
	}


}

package com.yiibai.core;

public class CustomerBo {
	public void printMsg(String msg) {

		System.out.println("CustomerBo : " + msg);
	}
}

package com.yiibai.core;

public class SchedulerBo {
	public void printMsg(String msg) {

		System.out.println("SchedulerBo : " + msg);
	}
}

二、AppConfig(相当于配置文件)

package com.yiibai.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.yiibai.core.CustomerBo;

@Configuration
public class CustomerConfig {
	
	@Bean(name="customer")
	public CustomerBo customerBo(){
		
		return new CustomerBo();
		
	}
}

package com.yiibai.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import com.yiibai.core.SchedulerBo;

@Configuration
public class SchedulerConfig {
	
	@Bean(name="scheduler")
	public SchedulerBo suchedulerBo(){
		
		return new SchedulerBo();
		
	}
	
}

package com.yiibai.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;

import com.yiibai.core.HelloWorldImpl;
import com.yiibai.core.IHelloWorld;

@Configuration
@Import({ CustomerConfig.class, SchedulerConfig.class })
public class AppConfig {
	
    @Bean(name="helloBean")
    public IHelloWorld helloWorld() {
        return new HelloWorldImpl();
    }
	
}

三、测试（主类）

package com.yiibai.config;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

import com.yiibai.core.CustomerBo;
import com.yiibai.core.IHelloWorld;
import com.yiibai.core.SchedulerBo;

public class App {

	private static ApplicationContext context;

	public static void main(String[] args) {
		context = new AnnotationConfigApplicationContext(AppConfig.class);
        IHelloWorld obj = (IHelloWorld) context.getBean("helloBean");
    
    obj.printHelloWorld("Spring Java Config");

	CustomerBo customer = (CustomerBo) context.getBean("customer");
	customer.printMsg("Hello 11");

	SchedulerBo scheduler = (SchedulerBo) context.getBean("scheduler");
	scheduler.printMsg("Hello 22");
	}

}

四、运行

五、set函数注入bean属性的情况：

AppConfig类内增加下面的代码：

    @Bean(name="helloBean1")
    public IHelloWorld helloWorld1() {
       HelloWorldImpl myhello= new HelloWorldImpl();
       myhello.setName("Yiibai");
       return myhello; 
    }

等价于以下的XML配置：

	<bean id="helloBean1" class="com.yiibai.core.HelloWorldImpl">
		<property name="name" value="Yiibai" />
	</bean>

六、无xml配置AOP

两点：

1、AOP类加上下面的注释

@Component
@Aspect

增加AOP类---AopConfig内容如下：

package com.yiibai.config;

import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;

@Component
@Aspect
public class AopConfig {
	/*Pointcut for printMsg*/
	@Pointcut("execution(* *.printMsg(*))")
	public void printpoint() {
	}
	
	@Before("printpoint()")
	public void beforepoint() {
		System.out.println("接下去调用printMsg()......");
	}
	
	@AfterReturning("printpoint()")
	public void afterprint() {
		System.out.println("函数printMsg()执行结束......");
	}
}

2、JavaConfig类加上：

@ComponentScan
@EnableAspectJAutoProxy

修改后的JavaConfig类---AppConfig代码如下：

package com.yiibai.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
import org.springframework.context.annotation.Import;
import com.yiibai.core.HelloWorldImpl;
import com.yiibai.core.IHelloWorld;

@Configuration
@ComponentScan
@EnableAspectJAutoProxy 
@Import({ CustomerConfig.class, SchedulerConfig.class })
public class AppConfig {
	
    @Bean(name="helloBean")
    public IHelloWorld helloWorld() {
        return new HelloWorldImpl();
    }
	
}

运行：

七、混用XML与Java装配方式

包com.yiibai.config下创建配置文件applicationContext.xml（本人习惯把配置文件放在包里，这样便于随包整体转移到其他项目而不必修改代码）：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
	http://www.springframework.org/schema/beans/spring-beans-4.0.xsd">

	<bean id="helloBean" class="com.yiibai.core.HelloWorldImpl">
		<property name="name" value="Yiibai" />
	</bean>

</beans>

用来注册helloBean。

对AppConfig如下修改：

1）@Configuration前加上@ImportResource("classpath:com/yiibai/core/applicationContext.xml")

2）注释helloBean的内容。

修改好的内容：

package com.yiibai.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.context.annotation.ImportResource;

@ImportResource("classpath:com/yiibai/core/applicationContext.xml")
@Configuration
@Import({ CustomerConfig.class, SchedulerConfig.class })
public class AppConfig {

}

测试代码和运行结果都不变

（也不是完全不变，会多出一条类似如下的消息

2017-10-10 22:45:49 [org.springframework.beans.factory.xml.XmlBeanDefinitionReader]-[INFO] Loading XML bean definitions from class path resource [com/yiibai/core/applicationContext.xml]
）

如需要在xml配置AOP，则applicationContext.xml内容如下：

<?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:context="http://www.springframework.org/schema/context"
	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
	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/tx
                         http://www.springframework.org/schema/tx/spring-tx-4.3.xsd
                         http://www.springframework.org/schema/aop 
                         http://www.springframework.org/schema/aop/spring-aop-4.3.xsd ">
	<context:annotation-config />	
	 <aop:aspectj-autoproxy />
	
	<bean id="helloBean" class="com.yiibai.core.HelloWorldImpl">
		<property name="name" value="Yiibai" />
	</bean>
	
	<!--定义切面 -->
	<bean id="aopConfig" class="com.yiibai.config.AopConfig" />

</beans>

类方式注入使用aop需将<aop:aspectj-autoproxy> 改为<aop:aspectj-autoproxy proxy-target-class="true"/> 或 <aop:config proxy-target-class="true"> </aop:config>,否则会出现cannot be cast to .......错误.

七、注意：Web环境中使用JavaConfig，需要在web.xml中加入如下代码：

<context-param>  
    <param-name>contextClass</param-name>  
    <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>  
</context-param>  
<context-param>  
    <param-name>contextConfigLocation</param-name>  
    <param-value>com.packtpub.learnvaadin.springintegration.SpringIntegrationConfiguration</param-value>  
</context-param>

代码下载

参考：

Spring进行面向切面编程的一个简单例子

史上最全最强SpringMVC详细示例实战教程

Spring JavaConfig实例

Spring @Configuration使用

使用@Configuration注解来代替Spring的bean配置

来源：oschina

链接：https://my.oschina.net/u/2245781/blog/1548807

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Spring