Spring EL regular expression example
Spring EL supports regular expression using a simple keyword “matches“, which is really awesome! For examples,
@Value("#{'100' matches '\\d+' }")
private boolean isDigit;
It test whether ‘100‘ is a valid digit via regular expression ‘\\d+‘.
Spring EL in Annotation
See following Spring EL regular expression examples, some mixed with ternary operator, which makes Spring EL pretty flexible and powerful.
Below example should be self-explanatory.
package com.mkyong.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,})$";
// if this is a digit?
@Value("#{'100' matches '\\d+' }")
private boolean validDigit;
// if this is a digit + ternary operator
@Value("#{ ('100' matches '\\d+') == true ? " +
"'yes this is digit' : 'No this is not a digit' }")
private String msg;
// if this emailBean.emailAddress contains a valid email address?
@Value("#{emailBean.emailAddress matches customerBean.emailRegEx}")
private boolean validEmail;
//getter and setter methods, and constructor
}
package com.mkyong.core;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
@Component("emailBean")
public class Email {
@Value("[email protected]")
String emailAddress;
//...
}
Output
Customer [isDigit=true, msg=yes this is digit, isValidEmail=true]
Spring EL in XML
See equivalent version in bean definition XML file.
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
<bean id="customerBean" class="com.mkyong.core.Customer">
<property name="validDigit" value="#{'100' matches '\d+' }" />
<property name="msg"
value="#{ ('100' matches '\d+') == true ? 'yes this is digit' : 'No this is not a digit' }" />
<property name="validEmail"
value="#{emailBean.emailAddress matches '^[_A-Za-z0-9-]+(\.[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\.[A-Za-z0-9]+)*(\.[A-Za-z]{2,})$' }" />
</bean>
<bean id="emailBean" class="com.mkyong.core.Email">
<property name="emailAddress" value="[email protected]" />
</bean>
</beans>
Download Source Code
Download It – Spring3-EL-Regular-Expression-Example.zip (6 KB)
Are u shure that an email could start with ‘-‘ (minus)? With your regexp it’s possible. See: 3.4. Address Specification on RFC 5322. Better use: ^[_A-Za-z0-9]+(\\.[_A-Za-z0-9]+)*@[A-Za-z0-9]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$