spring （1）demo 初识IoC容器

最近开始学习spring，第一天 先敲一个 实例demo，大概了解

1.新建一个java project，导入项目所学的jar包，这个jar包很复杂，本来打算用spring-framework3.3.1的，可以去了spring官网发现没有这个版本的可以下载，而且都是maven与gradle有关的，这里推荐一个比较好的下载jar的地址：

http://repo.springsource.org/libs-release-local/org/springframework/spring/3.2.1.RELEASE/

在这里下载的jar比较靠谱，另外在往工程里面加入jar包的时候学会new user library这一类的包，这样项目中的jar包就不是很乱，分类比较清楚

2.新建com.bean包

写一个person接口

package com.bean;

public interface Person {
	public void speak();

}

 3.新建两个实现这个接口的类

package com.bean;

public class ChineseImpl implements Person {
	private String name;
	private int age;
	
	

	public String getName() {
		return name;
	}



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



	public int getAge() {
		return age;
	}



	public void setAge(int age) {
		this.age = age;
	}



	@Override
	public void speak() {
		System.out.println("chinese,name,age"+this.name+this.age);
		
	}
	
}

 

另一个

package com.bean;

public class AmericanImpl implements Person {

	private String name;
	private int age;
	
	

	public String getName() {
		return name;
	}



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



	public int getAge() {
		return age;
	}



	public void setAge(int age) {
		this.age = age;
	}



	@Override
	public void speak() {
		System.out.println("american,name,age"+this.name+this.age);
		
	}
}

 在spring中，spring容器负责调用这两个类的setter方法以设置实例中属性的值。 这里要用到xml的配置文件

4在src下新建applicationContext.xml这个配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"  
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
    xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"  
    xmlns:context="http://www.springframework.org/schema/context"  
    xsi:schemaLocation="http://www.springframework.org/schema/beans  http://www.springframework.org/schema/beans/spring-beans-3.0.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-3.0.xsd   
     http://www.springframework.org/schema/jee  http://www.springframework.org/schema/jee/spring-jee-3.0.xsd   
     http://www.springframework.org/schema/context  http://www.springframework.org/schema/context/spring-context-3.0.xsd"  
    default-lazy-init="true" default-autowire="byName">  
    
    
    <bean id="chinese" class="com.bean.ChineseImpl">
    <property name="name"><value>小明</value></property>
      <property name="age"><value>10</value></property>
    </bean>
    
    
    <bean id="american" class="com.bean.AmericanImpl">
    <property name="name"><value>jack</value></property>
      <property name="age"><value>10</value></property>
    </bean>
    
    
    
    
    
</beans>

 在配置文件中，他帮我们办了这样一件事，就是

<bean id="chinese" class="com.bean.ChineseImpl">
    <property name="name"><value>小明</value></property>
      <property name="age"><value>10</value></property>
    </bean>
就是
ChineseImpl chinese=new ChineseImpl();
chinese.setName("小明");
chinese.setAge("10");
这样的作用

5新建com.spring包，新建test类

package com.spring;

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

import com.bean.Person;

public class Test {
	public static void main(String[] args) {
		System.out.println("a");
		ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
		Person person=(Person)context.getBean("chinese");
		person.speak();
		//person=(Person)context.getBean("american");
		//person.speak();
	}

}

 6查看输出的结果