Spring的DI初步

DI：依赖注入

第一个DEMO：域属性注入

　　java类：（Car类和Stu类，学生有一辆小汽车）

 package cn.dawn.day02di;

 /**

  * Created by Dawn on 2018/3/3.

  *///小汽车类public class Car {

     private String type;

     private String color;

     public String getType() {

         return type;

     }

     public void setType(String type) {

         this.type = type;

     }

     public String getColor() {

         return color;

     }

     public void setColor(String color) {

         this.color = color;

     }

 }

package cn.dawn.day02di;

/**

 * Created by Dawn on 2018/3/3.

 *///学生类public class Stu {

    private String name;

    private Integer age;

    private Car car;

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public Integer getAge() {

        return age;

    }

    public void setAge(Integer age) {

        this.age = age;

    }

    public Car getCar() {

        return car;

    }

    public void setCar(Car car) {

        this.car = car;

    }

}

配置xml中

<?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.xsd">

    <!--汽车-->

    <bean id="car" class="cn.dawn.day02di.Car">

        <property name="type" value="奔驰"></property>

        <property name="color" value="红色"></property>

    </bean>

    <!--学生-->

    <!--这儿的小汽车不能用value，用ref引用上面的那个汽车car-->

    <bean id="stu" class="cn.dawn.day02di.Stu">

        <property name="name" value="孟六"></property>

        <property name="age" value="20"></property>

        <property name="car" ref="car"></property>

    </bean>

</beans>

　测试类

package cn.dawn.day02;

import cn.dawn.day02di.Stu;

import org.junit.Test;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

/**

 * Created by Dawn on 2018/3/3.

 */public class test20180303 {

    @Test

    /*域属性*/

    public void t01(){

        ApplicationContext context=new ClassPathXmlApplicationContext("ApplicationContext-day02.xml");

        Stu stu = (Stu) context.getBean("stu");

        System.out.println(stu.getName()+"开"+stu.getCar().getType());

    }

}

第二个Demo：打印机案例

项目架构

 package cn.dawn.day03printer.ink;

 /**

  * Created by Dawn on 2018/3/3.

  *//*墨盒*/public interface Ink {

     public String getInkColor();

 }

 package cn.dawn.day03printer.ink;

 /**

  * Created by Dawn on 2018/3/3.

  *//*彩色墨盒*/public class ColorInk implements Ink {

     public String getInkColor() {

         return "彩色墨盒";

     }

 }

 package cn.dawn.day03printer.ink;

 /**

  * Created by Dawn on 2018/3/3.

  *//*黑白墨盒*/public class BlackInk implements Ink {

     public String getInkColor() {

         return "黑白墨盒";

     }

 }

 package cn.dawn.day03printer.paper;

 /**

  * Created by Dawn on 2018/3/3.

  *//*纸张*/public interface Paper {

     public String getPagerSize();

 }

 package cn.dawn.day03printer.paper;

 /**

  * Created by Dawn on 2018/3/3.

  *//*B5纸张*/public class B5Paper implements Paper{

     public String getPagerSize() {

         return "B5纸";

     }

 }

 package cn.dawn.day03printer.paper;

 /**

  * Created by Dawn on 2018/3/3.

  *//*A4纸张*/public class A4Paper implements Paper {

     public String getPagerSize() {

         return "A4纸";

     }

 }

 package cn.dawn.day03printer.printer;

 import cn.dawn.day03printer.ink.Ink;

 import cn.dawn.day03printer.paper.Paper;

 /**

  * Created by Dawn on 2018/3/3.

  *//*打印机*/public class Printer {

     /*墨盒*/

     private Ink ink;

     /*纸张*/

     private Paper paper;

     /*打印方法*/

     public void print(){

         System.out.println("我们的喷墨打印机，用"+ink.getInkColor()+"和"+paper.getPagerSize()+"打印出了------》我爱Spring");

     }

     public Ink getInk() {

         return ink;

     }

     public void setInk(Ink ink) {

         this.ink = ink;

     }

     public Paper getPaper() {

         return paper;

     }

     public void setPaper(Paper paper) {

         this.paper = paper;

     }

 }

　　配置文件中：

<?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.xsd">

    <!--墨盒-->

    <bean id="ink" class="cn.dawn.day03printer.ink.ColorInk"></bean>

    <!--纸张-->

    <bean id="paper" class="cn.dawn.day03printer.paper.A4Paper"></bean>

    <!--打印机-->

    <bean id="printer" class="cn.dawn.day03printer.printer.Printer">

        <property name="ink" ref="ink"></property>

        <property name="paper" ref="paper"></property>

     </bean>

</beans>

　　单测方法

package cn.dawn.day03;

import cn.dawn.day02di.Stu;

import cn.dawn.day03printer.printer.Printer;

import org.junit.Test;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

/**

 * Created by Dawn on 2018/3/3.

 */public class test20180303 {

    @Test

    /*打印机案例*/

    public void t01(){

        ApplicationContext context=new ClassPathXmlApplicationContext("ApplicationContext-day03.xml");

        Printer printer = (Printer) context.getBean("printer");

        printer.print();

    }

}

巴特西

Spring的DI初步

DI：依赖注入

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