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  • Spring EL Operators example

    Spring EL supports most of the standard mathematical, logical or relational operators. For example,

    • Relational operators – equal (==, eq), not equal (!=, ne), less than (<, lt), less than or equal (<= , le), greater than (>, gt), and greater than or equal (>=, ge).
    • Logical operators – and, or, and not (!).
    • Mathematical operators – addition (+), Subtraction (-), Multiplication (*), division (/), modulus (%) and exponential power (^).

    Spring EL in Annotation

    This example demonstrates the use of operators in SpEL.

    package com.mkyong.core;
    
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.stereotype.Component;
    
    @Component("customerBean")
    public class Customer {
    
    	//Relational operators
    	
    	@Value("#{1 == 1}") //true
    	private boolean testEqual;
    	
    	@Value("#{1 != 1}") //false
    	private boolean testNotEqual;
    	
    	@Value("#{1 < 1}") //false
    	private boolean testLessThan;
    	
    	@Value("#{1 <= 1}") //true
    	private boolean testLessThanOrEqual;
    	
    	@Value("#{1 > 1}") //false
    	private boolean testGreaterThan;
    	
    	@Value("#{1 >= 1}") //true
    	private boolean testGreaterThanOrEqual;
    
    	//Logical operators , numberBean.no == 999
    	
    	@Value("#{numberBean.no == 999 and numberBean.no < 900}") //false
    	private boolean testAnd;
    	
    	@Value("#{numberBean.no == 999 or numberBean.no < 900}") //true
    	private boolean testOr;
    	
    	@Value("#{!(numberBean.no == 999)}") //false
    	private boolean testNot;
    
    	//Mathematical operators
    	
    	@Value("#{1 + 1}") //2.0
    	private double testAdd;
    	
    	@Value("#{'1' + '@' + '1'}") //1@1
    	private String testAddString;
    	
    	@Value("#{1 - 1}") //0.0
    	private double testSubtraction;
    
    	@Value("#{1 * 1}") //1.0
    	private double testMultiplication;
    	
     	@Value("#{10 / 2}") //5.0
    	private double testDivision;
    	
    	@Value("#{10 % 10}") //0.0
    	private double testModulus ;
    	
    	@Value("#{2 ^ 2}") //4.0
    	private double testExponentialPower;
    
    	@Override
    	public String toString() {
    		return "Customer [testEqual=" + testEqual + ", testNotEqual="
    				+ testNotEqual + ", testLessThan=" + testLessThan
    				+ ", testLessThanOrEqual=" + testLessThanOrEqual
    				+ ", testGreaterThan=" + testGreaterThan
    				+ ", testGreaterThanOrEqual=" + testGreaterThanOrEqual
    				+ ", testAnd=" + testAnd + ", testOr=" + testOr + ", testNot="
    				+ testNot + ", testAdd=" + testAdd + ", testAddString="
    				+ testAddString + ", testSubtraction=" + testSubtraction
    				+ ", testMultiplication=" + testMultiplication
    				+ ", testDivision=" + testDivision + ", testModulus="
    				+ testModulus + ", testExponentialPower="
    				+ testExponentialPower + "]";
    	}
    	
    }
    
    package com.mkyong.core;
    
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.stereotype.Component;
    
    @Component("numberBean")
    public class Number {
    
    	@Value("999")
    	private int no;
    
    	public int getNo() {
    		return no;
    	}
    
    	public void setNo(int no) {
    		this.no = no;
    	}
    
    }
    

    Run it

           Customer obj = (Customer) context.getBean("customerBean");
           System.out.println(obj);
    

    Output

    Customer [
    	testEqual=true, 
    	testNotEqual=false, 
    	testLessThan=false, 
    	testLessThanOrEqual=true, 
    	testGreaterThan=false, 
    	testGreaterThanOrEqual=true, 
    	testAnd=false, 
    	testOr=true, 
    	testNot=false, 
    	testAdd=2.0, 
    	testAddString=1@1, 
    	testSubtraction=0.0, 
    	testMultiplication=1.0, 
    	testDivision=5.0, 
    	testModulus=0.0, 
    	testExponentialPower=4.0
    ]
    

    Spring EL in XML

    See equivalent version in bean definition XML file. In XML, symbol like "less than" is always not support, instead, you should use the textual equivalents shown above, for example, ('<' = 'lt') and ('<=' = 'le').

    <beans xmlns="http://www.springframework.org/schema/beans"
    	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    	xsi:schemaLocation="http://www.springframework.org/schema/beans
    	http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
    
    	<bean id="customerBean" class="com.mkyong.core.Customer">
    	
    	  <property name="testEqual" value="#{1 == 1}" />
    	  <property name="testNotEqual" value="#{1 != 1}" />
    	  <property name="testLessThan" value="#{1 lt 1}" />
    	  <property name="testLessThanOrEqual" value="#{1 le 1}" />
    	  <property name="testGreaterThan" value="#{1 > 1}" />
    	  <property name="testGreaterThanOrEqual" value="#{1 >= 1}" />
    		
    	  <property name="testAnd" value="#{numberBean.no == 999 and numberBean.no lt 900}" />
    	  <property name="testOr" value="#{numberBean.no == 999 or numberBean.no lt 900}" />
    	  <property name="testNot" value="#{!(numberBean.no == 999)}" />
    		
    	  <property name="testAdd" value="#{1 + 1}" />
    	  <property name="testAddString" value="#{'1' + '@' + '1'}" />
    	  <property name="testSubtraction" value="#{1 - 1}" />
    	  <property name="testMultiplication" value="#{1 * 1}" />
    	  <property name="testDivision" value="#{10 / 2}" />
    	  <property name="testModulus" value="#{10 % 10}" />
    	  <property name="testExponentialPower" value="#{2 ^ 2}" />
    		
    	</bean>
    	
    	<bean id="numberBean" class="com.mkyong.core.Number">
    		<property name="no" value="999" />
    	</bean>
    
    </beans>
    
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  • 原文地址:https://www.cnblogs.com/ghgyj/p/4749591.html
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