从头认识Spring-1.15 对SpEl的值的操作-逻辑运算以及条件表达式

Posted 李灵晖

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这一章节我们来讨论一下对SpEl的逻辑运算以及条件表达式。

1.domain

烤炉类：（修改了toString方法，因为配置文件的表达式需要只返回跟Bean的id相同的name的属性值）

package com.raylee.my_new_spring.my_new_spring.ch01.topic_1_18;

public class Oven {
	private String name = "";

	private double size = 0;

	private boolean bigOrNot = false;

	public boolean isBigOrNot() {
		return bigOrNot;
	}

	public void setBigOrNot(boolean bigOrNot) {
		this.bigOrNot = bigOrNot;
	}

	public double getSize() {
		return size;
	}

	public void setSize(double size) {
		this.size = size;
	}

	@Override
	public String toString() {
		return name;
	}

	public String getName() {
		return name;
	}

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

}


厨师类：（不变）

package com.raylee.my_new_spring.my_new_spring.ch01.topic_1_18;

public class Chief {

	private String name = "";

	private Oven oven;

	public void checkOven() {
		if (getOven().isBigOrNot()) {
			System.out.println(getOven());
			System.out.println("oven is big");
		} else {
			System.out.println(getOven());
			System.out.println("oven is not big");
		}
	}

	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;
	}
}



2.测试类：（为了方便，我们只是用jack）

package com.raylee.my_new_spring.my_new_spring.ch01.topic_1_18;

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_18/ApplicationContext-test.xml" })
public class ChiefTest {

	@Autowired
	private ApplicationContext applicationContext;

	@Test
	public void testChief() {
		Chief jack = (Chief) applicationContext.getBean("jack");
		jack.checkOven();		
	}
}



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.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="smallOven"
		class="com.raylee.my_new_spring.my_new_spring.ch01.topic_1_19.Oven"
		p:name="smallOven" p:size="#{2*5}" p:bigOrNot="#{10 >= 8 and 2 > 3}" />

	<bean id="midOven"
		class="com.raylee.my_new_spring.my_new_spring.ch01.topic_1_19.Oven"
		p:name="smallOven" p:size="#{3*5}" p:bigOrNot="#{1 == 2}" />


	<bean id="jack"
		class="com.raylee.my_new_spring.my_new_spring.ch01.topic_1_19.Chief"
		p:name="jack">
		<property name="oven" ref="#{jack.name=='jack'?smallOven:midOven}" />
	</bean>

</beans>



配置文件的重点就是看Oven里面的p:bigOrNot属性，在这里我们不单是通过对比符号来对比两个值，而且还引入逻辑运算符and（还有or和not）；还有一个就是在jack的Bean的oven属性，我们使用条件表达式，根据名称来决定使用哪个烤炉。

测试输出：

smallOven
oven is not big


总结：这一章节我们讨论了对SpEl的逻辑运算以及条件表达式。


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

 

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