从头认识Spring-1.7 如何通过属性注入Bean?(1)-如何通过属性向对象注入值?

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

<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>


<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>


是一样的

 可是像以下的全然的大写,就会抛异常

<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>


 

測试输出:

0
Blueberry Cheesecake
7.0

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:http://blog.csdn.net/raylee2007/article/details/50611627 

 

我的github:https://github.com/raylee2015/my_new_spring

原文地址:https://www.cnblogs.com/gccbuaa/p/7249788.html