Struts 2 s:sort control tag

by

s:sort:

The s:sort tag is used to sort a List by using java.util.Comparator.
Syntax:
<s:sort comparator=”#comparatorName” source=”fieldName”>

Example:

index.jsp

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
  	<title>Struts 2 s:sort control tag example</title>
	<META HTTP-EQUIV="Refresh" CONTENT="0;URL=Test.action">
  </head>  
  <body>
  </body>
</html>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	xmlns="http://java.sun.com/xml/ns/javaee" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
 
 
 	<filter>
	  <filter-name>struts2</filter-name>
	  <filter-class>
        	org.apache.struts2.dispatcher.ng.
        	filter.StrutsPrepareAndExecuteFilter
          </filter-class>
	</filter>
 
	<filter-mapping>
		<filter-name>struts2</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
 
	<welcome-file-list>
	  <welcome-file>index.jsp</welcome-file>
	</welcome-file-list>
 
</web-app>

struts.xml

<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
 
<struts>
 
	<package name="default" extends="struts-default">
		<action name="Test" class="com.w3schools.action.Test">
			<result name="success">/test.jsp</result>
		</action>
	</package>
 
</struts>

Test.java

import java.util.ArrayList;
import java.util.List;
import com.opensymphony.xwork2.ActionSupport;
 
/**
 * This class is used as an action class.
 * @author w3schools
 */
public class Test extends ActionSupport{
	//data members
	private List<Subject> subjectList;
 
	//business logic
	public String execute(){
		subjectList = new ArrayList<Subject>();
		subjectList.add(new Subject("Java","1"));
		subjectList.add(new Subject("Networking","2"));
		subjectList.add(new Subject("Compiler","3"));
		subjectList.add(new Subject("DBMS","4"));
 
		return SUCCESS;	
	}
 
	//getter setters
	public List<Subject> getSubjectList() {
		return subjectList;
	}
 
	public void setSubjectList(List<Subject> subjectList) {
		this.subjectList = subjectList;
	}	
}

SubjectNameComparator.java

import java.util.Comparator;
 
/**
 * This class is used to compare the Subject 
 * objects based on the subject name.
 * @author w3schools
 */
public class SubjectNameComparator implements Comparator<Subject>{
	public int compare(Subject subject1, Subject subject2) { 
		return subject1.getSubjectName().
				compareTo(subject2.getSubjectName());
	}
}

welcome.jsp

<%@ taglib uri="/struts-tags" prefix="s"%>
<html>
	<head>
		<title>Struts 2 s:sort control tag example</title>
	</head>
	<body>
		<h3>This is a s:sort control tag example.</h3>		
		<s:bean 
                  name="com.w3schools.action.SubjectNameComparator"
		  var="subjectNameComparator" />
 
		<h4>Iterator values</h4>
		<s:iterator value="subjectList">
			Subject Name: <s:property value="subjectName"/> , 
			Subject Id: <s:property value="subjectId"/><br/>
		</s:iterator>
 
	       <s:sort comparator="#subjectNameComparator" 
                                                 source="subjectList">
		<h4>Iterator values after sorting by subject name</h4>
		<s:iterator>
			Subject Name: <s:property value="subjectName"/> , 
			Subject Id: <s:property value="subjectId"/><br/>
		</s:iterator>
		</s:sort>
 
	</body>
</html>

Output:

struts 47
 
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