这一章节我们来讨论一下如何通过属性注入Bean?
这一章节分为两部分,第一部分我们通过属性向对象注入值,第二部分我们通过属性向对象注入还有一个对象的引用。
1.如何通过属性向对象注入值?
(1)domain
package com.raylee.my_new_spring.my_new_spring.ch01.topic_1_7;public class Cake { private final int id = index++; private static int index = 0; private String name = ""; private double size = 0; public String getName() { return name; } public void setName(String name) { this.name = name; } public double getSize() { return size; } public void setSize(double size) { this.size = size; } public int getId() { return id; } @Override public String toString() { return "create the cake,its id:" + id + ", size:" + size + " inch ,name:" + name; }}这一个领域类我们仅仅须要一个Cake就够了。可是我们在里面会加上名称(name)和大小(size)这两个属性,然后我们通过Spring来帮我们赋值。
(2)測试类:
package com.raylee.my_new_spring.my_new_spring.ch01.topic_1_7;import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.context.ApplicationContext;import org.springframework.test.context.ContextConfiguration;import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration(locations = { "/com/raylee/my_new_spring/my_new_spring/ch01/topic_1_7/ApplicationContext-test.xml" })public class CakeTest { @Autowired private ApplicationContext applicationContext; @Test public void testChief() { Cake cake = applicationContext.getBean(Cake.class); System.out.println(cake.getId()); System.out.println(cake.getName()); System.out.println(cake.getSize()); }}没什么特别。仅仅须要get那个Bean出来,然后打印一下几个属性就可以。
(3)配置文件
xml version="1.0" encoding="UTF-8"?
> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.1.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.0.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd"> <bean id="cake" class="com.raylee.my_new_spring.my_new_spring.ch01.topic_1_7.Cake"> <property name="name" value="Blueberry Cheesecake" /> <property name="size" value="7" /> </bean> </beans>
配置文件比較重要,我们在Bean里面须要插入property这个标签,然后name这个属性须要跟我们的domain类的属性名字一样。注意:这里首字母能够不区分大写和小写
也就是
和
是一样的
可是像以下的全然的大写,就会抛异常
測试输出:
0
Blueberry Cheesecake7.0
总结:这一章节主要介绍了如何通过属性向对象注入值,还有中间须要注意的大写和小写的问题
文件夹:
我的github: