spring的HelloWorld

spring的核心是IoC、DI，下面是一个spring的HelloWorld，体现了IoC、DI的思想

第一步：引入spring的jar包

第二步：创建一个接口类

package cleversoft.spring3;

public interface HelloApi {
    public String helloSpring3(int a);
}

第三步：创建接口的实现类

package cleversoft.spring3;

public class HelloImpl implements HelloApi{

	@Override
	public String helloSpring3(int a) {
		System.out.println("Hello, spring3,a="+a);
		return "spring3,a="+a;
	}

}

第四步：创建客户端来测试

package cleversoft.spring3;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Client {
	public static void main(String args[]) {
		ApplicationContext ctx = new ClassPathXmlApplicationContext(
				new String[] { "applicationContext.xml" });
		HelloApi api = (HelloApi)ctx.getBean("aa");
		api.helloSpring3(22);
	}
}

第五步：在src的根目录下创建applicationContext.xml文件

<?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:tx="http://www.springframework.org/schema/tx"
		xsi:schemaLocation="
			http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
			http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
			http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">

        <bean name="aa" class="cleversoft.spring3.HelloImpl"></bean>
</beans>

第六步：运行Client.java，打印如下结果表示成功

Hello, spring3,a=22