Java 系列之spring学习--依赖注入（二）

一、依赖注入的三种方式

　　接口注入，set注入，构造函数注入

二、构造函数注入

　　2.1、测试类

package test;

public class test01 {

	public String msg=null;
	public test01(String msg)
	{
		System.out.println(msg);

	}
	public void prints()
	{

		System.out.println("prints");
	}
}

　　　2.2、编辑applicationContext.xml

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

   <!-- 构造函数注入 -->
    <bean id="test01" class="test.test01">
    <constructor-arg index="0">
   			<value>dirk</value>
    </constructor-arg>
     <constructor-arg index="1">
   			<value>dirk2</value>
    </constructor-arg>
    </bean> 

</beans>

　　　2.3、测试　

package test;

public class test01 {

	public String msg=null;
	public String msg1=null;
	public test01(String msg,String msg1)
	{
		System.out.println(msg+msg1);

	}
	public void prints()
	{

		System.out.println("prints");
	}
}

package test;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

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

public class aservlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
		test02 test01=(test02)context.getBean("test02");
		test01.getMsg();
	}

}

三、set注入　　

　　3.1测试类

package test;

public class test02 {
	public String msg;

	public String getMsg() {
		return msg;
	}

	public void setMsg(String msg) {
		this.msg = msg;
	}
}

　3.2、配置文件修改　

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

    <bean id="test02" class="test.test02">
    	<property name="msg">
    		<value>drik.wang</value>
    	</property>
    </bean>
</beans>

package test;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

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

public class aservlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
		test02 test01=(test02)context.getBean("test02");
		test01.getMsg();
	}

}

　　3.3、测试

package test;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

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

public class aservlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
		test02 test02=(test02)context.getBean("test02");
		System.out.println(test02.getMsg());
	}

}

四、实例

　　4.1、项目结构

　　4.2、数据层接口

　　4.2、数据层是实现类

　　4.4、业务层接口

　　4.5、业务层实现类

　　4.5、调用业务层

　　4.6、配置文件

　　4.7、结果