Spring学习-- SpEL表达式

本文内容纲要：

**Spring表达式语言(简称SpEL)：**是一个支持运行时查询和操作对象图的强大的表达式语言。

**语法类似于EL：**SpEL使用#{...}作为定界符,所有在大括号中的字符都将被认为是SpEL,SpEL为bean的属性进行动态赋值提供了便利。

通过SpEL可以实现：

通过bean的id对bean进行引用。

调用方式以及引用对象中的属性。

计算表达式的值

正则表达式的匹配。

1 2<beansxmlns="http://www.springframework.org/schema/beans" 3xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans.xsd"> 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

1packagecom.itdjx.spring.spel; 2 3/** 4*@authorWángChéngDá 5*@create2017-03-0213:26 6*/ 7publicclassCar{ 8 9privateStringbrand; 10 11privatedoubleprice; 12 13privateStringperimeter; 14 15publicStringgetBrand(){ 16returnbrand; 17} 18 19publicvoidsetBrand(Stringbrand){ 20this.brand=brand; 21} 22 23publicdoublegetPrice(){ 24returnprice; 25} 26 27publicvoidsetPrice(doubleprice){ 28this.price=price; 29} 30 31publicStringgetPerimeter(){ 32returnperimeter; 33} 34 35publicvoidsetPerimeter(Stringperimeter){ 36this.perimeter=perimeter; 37} 38 39@Override 40publicStringtoString(){ 41return"Car{"+ 42"brand="+brand++ 43",price="+price+ 44",perimeter="+perimeter++ 45}; 46} 47}

1packagecom.itdjx.spring.spel; 2 3/** 4*@authorWángChéngDá 5*@create2017-03-0213:48 6*/ 7publicclassAddress{ 8 9privateStringprovince; 10 11privateStringcity; 12 13privateStringarea; 14 15publicStringgetProvince(){ 16returnprovince; 17} 18 19publicvoidsetProvince(Stringprovince){ 20this.province=province; 21} 22 23publicStringgetCity(){ 24returncity; 25} 26 27publicvoidsetCity(Stringcity){ 28this.city=city; 29} 30 31publicStringgetArea(){ 32returnarea; 33} 34 35publicvoidsetArea(Stringarea){ 36this.area=area; 37} 38 39@Override 40publicStringtoString(){ 41return"Address{"+ 42"province="+province++ 43",city="+city++ 44",area="+area++ 45}; 46} 47}

1packagecom.itdjx.spring.spel; 2 3/** 4*@authorWángChéngDá 5*@create2017-03-0213:27 6*/ 7publicclassPerson{ 8 9privateStringname; 10 11privateintage; 12 13privatebooleanmarriage; 14 15privateCarcar; 16 17privateStringsocialStatus; 18 19privateStringaddress; 20 21publicStringgetName(){ 22returnname; 23} 24 25publicvoidsetName(Stringname){ 26this.name=name; 27} 28 29publicintgetAge(){ 30returnage; 31} 32 33publicvoidsetAge(intage){ 34this.age=age; 35} 36 37publicbooleanisMarriage(){ 38returnmarriage; 39} 40 41publicvoidsetMarriage(booleanmarriage){ 42this.marriage=marriage; 43} 44 45publicCargetCar(){ 46returncar; 47} 48 49publicvoidsetCar(Carcar){ 50this.car=car; 51} 52 53publicStringgetSocialStatus(){ 54returnsocialStatus; 55} 56 57publicvoidsetSocialStatus(StringsocialStatus){ 58this.socialStatus=socialStatus; 59} 60 61publicStringgetAddress(){ 62returnaddress; 63} 64 65publicvoidsetAddress(Stringaddress){ 66this.address=address; 67} 68 69@Override 70publicStringtoString(){ 71return"Person{"+ 72"name="+name++ 73",age="+age+ 74",marriage="+marriage+ 75",car="+car+ 76",socialStatus="+socialStatus++ 77",address="+address++ 78}; 79} 80}

packagecom.itdjx.spring.spel;

importorg.springframework.context.ApplicationContext; importorg.springframework.context.support.ClassPathXmlApplicationContext;

/**

@authorWángChéngDá

@create2017-03-0213:42 */ publicclassMain{

publicstaticvoidmain(String[]args){

ApplicationContextapp=newClassPathXmlApplicationContext("spel-beans.xml"); Personperson=(Person)app.getBean("person"); System.out.println(person);

} }

控制台输出：

Person{name=华崽儿,age=25,marriage=false,car=Car{brand=玛莎拉蒂,price=32000.78,perimeter=238.13273272948624},socialStatus=金领,address=辽宁省大连市沙河口区}

SpEL字面量：

整数：#{8} 小数：#{8.8} 科学计数法：#{1e4} String：可以使用单引号或者双引号作为字符串的定界符号。 Boolean：#{true}

SpEL引用bean,属性和方法：

引用其他对象:#{car} 引用其他对象的属性：#{car.brand} 调用其它方法,还可以链式操作：#{car.toString()} 调用静态方法静态属性：#{T(java.lang.Math).PI}

SpEL支持的运算符号：

算术运算符：+，-，*，/，%，^(加号还可以用作字符串连接) 比较运算符：<,>,==,>=,<=,lt,gt,eg,le,ge 逻辑运算符：and,or,not,| if-else运算符(类似三目运算符)：？:(temary),?:(Elvis) 正则表达式：#{admin.emailmatches[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,4}}

本文内容总结：

原文链接：https://www.cnblogs.com/chinda/p/6490896.html