从头认识Spring-1.15 对SpEl的值的操作（1）-数值运算

这一章节我们来讨论一下对SpEl的值的运算。

1.domain

烤炉类：（不变）

package com.raylee.my_new_spring.my_new_spring.ch01.topic_1_17;public class Oven {private String name = "";private double size = 0;public double getSize() {return size;}public void setSize(double size) {this.size = size;}@Overridepublic String toString() {return name + " size:" + size;}public String getName() {return name;}public void setName(String name) {this.name = name;}}

厨师类：（为了方便，减少了friend的属性）

package com.raylee.my_new_spring.my_new_spring.ch01.topic_1_17;public class Chief {private String name = "";private Oven oven;public String getName() {return name;}public Oven getOven() {return oven;}public void setName(String name) {this.name = name;}public void setOven(Oven oven) {this.oven = oven;}public void userOven() {System.out.println(name + " use " + oven);}}

2.测试类：（不变）

package com.raylee.my_new_spring.my_new_spring.ch01.topic_1_17;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_17/ApplicationContext-test.xml" })public class ChiefTest {@Autowiredprivate ApplicationContext applicationContext;@Testpublic void testChief() {Chief jack = (Chief) applicationContext.getBean("jack");jack.userOven();Chief mike = (Chief) applicationContext.getBean("mike");mike.userOven();Chief rose = (Chief) applicationContext.getBean("rose");rose.userOven();}}

3.配置文件：（重点）

<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans"xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"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.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsdhttp://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.1.xsdhttp://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.0.xsdhttp://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="smallOven"class="com.raylee.my_new_spring.my_new_spring.ch01.topic_1_17.Oven"p:name="smallOven" p:size="#{2*3}" /><bean id="midOven"class="com.raylee.my_new_spring.my_new_spring.ch01.topic_1_17.Oven"p:name="smallOven" p:size="#{T(java.lang.Math).PI*4}" /><bean id="bigOven"class="com.raylee.my_new_spring.my_new_spring.ch01.topic_1_17.Oven"p:name="smallOven" p:size="#{smallOven.getSize()*4}" /><bean id="mike"class="com.raylee.my_new_spring.my_new_spring.ch01.topic_1_17.Chief"p:name="mike"><property name="oven" ref="smallOven" /></bean><bean id="jack"class="com.raylee.my_new_spring.my_new_spring.ch01.topic_1_17.Chief"p:name="jack"><property name="oven" ref="midOven" /></bean><bean id="rose"class="com.raylee.my_new_spring.my_new_spring.ch01.topic_1_17.Chief"p:name="rose"><property name="oven" ref="bigOven" /></bean></beans>

配置文件的重点就是看Oven里面的size属性，在这里我们可以通过运行符来计算我们需要的值，直接对SpEl的值进行操作。

测试输出：

jack use smallOven size:12.566370614359172
mike use smallOven size:6.0
rose use smallOven size:24.0

我们上面只是演示了乘法，它有：+ 加 - 减 * 乘 / 除 % 模 ^平方 这几种运算方式，大家后面可以逐一尝试。

总结：这一章节我们讨论了对SpEl的值的运算。

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

 

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