Spring EL支持正则表达式，可使用一个简单的关键词“matches”。如下实例，
@Value("#{'100' matches '\\d+' }")
private boolean isDigit;
它测试'100'是否是通过正则表达式‘\\d+‘测试过的一个有效的数字。
Spring EL以注解的形式
请参阅下面的 Spring EL 正则表达式的例子，这里有部分掺入三元运算符，这使得 Spring EL 非常灵活，功能强大。
下面的例子应该是不言自明的。
package com.yiibai.core;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
@Component("customerBean")
public class Customer {
// email regular expression
String emailRegEx = "^[_A-Za-z0-9-]+(\\.[_A-Za-z0-9-]+)" +
"*@[A-Za-z0-9]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";
// if this is a digit?
@Value("#{'100' matches '\\d+' }")
private boolean validDigit;
// if this is a digit + ternary operator
@Value("#{ ('100' matches '\\d+') == true ? " +
"'yes this is digit' : 'No this is not a digit' }")
private String msg;
// if this emailBean.emailAddress contains a valid email address?
@Value("#{emailBean.emailAddress matches customerBean.emailRegEx}")
private boolean validEmail;
//getter and setter methods, and constructor
}
package com.yiibai.core;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
@Component("emailBean")
public class Email {
@Value("admin@yiibai.com")
String emailAddress;
//...
}
输出
Customer [isDigit=true, msg=yes this is digit, isValidEmail=true]
Spring EL以XML的形式
请参阅在XML文件定义bean的等效版本。
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
<bean id="customerBean" class="com.yiibai.core.Customer">
<property name="validDigit" value="#{'100' matches '\d+' }" />
<property name="msg"
value="#{ ('100' matches '\d+') == true ? 'yes this is digit' : 'No this is not a digit' }" />
<property name="validEmail"
value="#{emailBean.emailAddress matches '^[_A-Za-z0-9-]+(\.[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\.[A-Za-z0-9]+)*(\.[A-Za-z]{2,})$' }" />
</bean>
<bean id="emailBean" class="com.yiibai.core.Email">
<property name="emailAddress" value="admin@yiibai.com" />
</bean>
</beans>
参考
