Spring 非常好用，其中就与他的注入有关，今天，浅谈一下Spring的基本注入，大神请飘过。
1、 添加maven支持
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-contextartifactId>
<version>4.0.2.RELEASEversion>
dependency>
基本的注入,只要这一个依赖项即可，我亲测。
2、 编写几个测试类
假设一个场景以便于代码逻辑
package com.cnblogs.yjmyzz.domain;
public abstract class Computer {
public abstract void showInfo();
}
package com.cnblogs.yjmyzz.domain;
public class MacBook extends Computer {
@Override
public void showInfo() {
System.out.println("\tApple MAC Book");
}
}
package com.cnblogs.yjmyzz.domain;
public class ThinkPad extends Computer {
@Override
public void showInfo() {
System.out.println("\tLenovo ThinkPad");
}
}
package com.cnblogs.yjmyzz.domain;
public abstract class Pet {
public abstract void welcomeMeToHome();
}
package com.cnblogs.yjmyzz.domain;
public class Dog extends Pet {
@Override
public void welcomeMeToHome() {
System.out.println("\twang! wang!");
}
}
package com.cnblogs.yjmyzz.domain;
import java.util.List;
public class Programmer {
private String name;
private Pet pet;
private List
public void setName(String name) {
this.name = name;
}
public List
return computers;
}
public void setComputers(List
this.computers = computers;
}
public void setPet(Pet pet) {
this.pet = pet;
}
public void show() {
System.out.print("My name is " + name);
System.out.print(", and I have " + computers.size() + " computer" + (computers.size() > 1 ? "s" : "") + ":");
System.out.println();
for (Computer c : computers) {
c.showInfo();
}
System.out.println("And I have a pet, everyday,when I go home, it will welcome me by ");
pet.welcomeMeToHome();
}
}
3、 spring的配置文件，这里是最基本配置文件，其余配置请自行添加
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">
<bean id="jimmy" class="com.cnblogs.yjmyzz.domain.Programmer">
<property name="name" value="jimmy.yang"/>
<property name="pet" ref="wangcai"/>
<property name="computers">
<list>
<ref bean="t60"/>
<ref bean="macbook_pro"/>
list>
property>
bean>
<bean id="t60" class="com.cnblogs.yjmyzz.domain.ThinkPad"/>
<bean id="macbook_pro" class="com.cnblogs.yjmyzz.domain.MacBook"/>
<bean id="wangcai" class="com.cnblogs.yjmyzz.domain.Dog"/>
beans>
这个配置文件SimpleBeans.xml中，一共配置了4个bean实例, 该配置被Spring容器加载后,这些对象都会被实例化(默认是单例模式实例化),并保持在容器中,需要使用的时候,可以手动通过ApplicationContext的getBean方法获取
4、 测试注入
为了方便，需要写一个工具类SpringUtils
package com.cnblogs.yjmyzz.utils;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class SpringUtils {
private static ApplicationContext applicationContext;
private static ApplicationContext getContext() {
if (applicatiOnContext== null) {
applicationContext = new ClassPathXmlApplicationContext("SimpleBeans.xml");
}
return applicationContext;
}
public static
return getContext().getBean(beanName, clazz);
}
}
然后就可以用这个工具类,通过getBean来获取注入的对象实例
package com.cnblogs.yjmyzz.test;
import com.cnblogs.yjmyzz.domain.Programmer;
import com.cnblogs.yjmyzz.utils.SpringUtils;
import org.junit.Test;
public class TestSpring {
@Test
public void testSimpleInject(){
Programmer jimmy= SpringUtils.getBean(Programmer.class,"jimmy");
jimmy.show();
}
}
以上代码从我的myeclipse复制出来的，亲测可用，如有疑问的地方请联系我。
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