Struts 2 + JSON Integration Annotation Example
January 03, 2015
Required Software to Run Example
To run the example, we need below software.1. Java 6
2. Tomcat 7
3. Eclipse
4. Maven
Project Structure in Eclipse
Find the project structure in eclipse for struts 2 and JSON integration.
Struts2 JSON Plugin
To resolve the struts 2 JSON API, we need the below plugin in our pom.xml<dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-json-plugin</artifactId> <version>2.3.20</version> </dependency>
json-default Parent Package
To support JSON, we need to use json-default in parent package. Use below annotation in the action class.
@ParentPackage("json-default")
json Result Type
The return type of action method should be JSON. To achieve it, struts 2 provides json type in result. Define it as below.@Result(name="success",type="json")
Action Class to Return JSON
Now find the action class where we are generating a sample JSON. We can use collection to create the required JSON. To get the output create setter and getter method of the property.Struts2JSON.java
package com.concretepage.action;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.struts2.convention.annotation.Action;
import org.apache.struts2.convention.annotation.ParentPackage;
import org.apache.struts2.convention.annotation.Result;
import com.opensymphony.xwork2.ActionSupport;
@Result(name="success",type="json")
@ParentPackage("json-default")
public class Struts2JSON extends ActionSupport{
private static final long serialVersionUID = 1L;
private List<String> listOfName = Arrays.asList("Ram","Shyam","Mohan");
private List<String> listOfCity = Arrays.asList("Varanasi","Jaunpur","Bhadohi");
private Map<String,List<String>> map = new HashMap<String,List<String>>();
{
map.put("names", listOfName);
map.put("cities", listOfCity);
}
private List<Map<String,List<String>>> result = new ArrayList<Map<String,List<String>>>();
{
result.add(map);
}
@Action("/json")
public String one() {
return SUCCESS;
}
public List<Map<String, List<String>>> getResult() {
return result;
}
public void setResult(List<Map<String, List<String>>> result) {
this.result = result;
}
}
web.xml for the Application
Find the web.xml for struts 2.web.xml
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<display-name>Struts 2 JSON </display-name>
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
<init-param>
<param-name>actionPackages</param-name>
<param-value>com.concretepage.action</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
Complete pom.xml Used in Example
Find the pom.xml that is being used in example to resolve struts 2 JAR dependency.pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.concretepage</groupId>
<artifactId>struts2json</artifactId>
<packaging>war</packaging>
<version>1</version>
<name>Struts2JSON</name>
<dependencies>
<dependency>
<groupId>org.apache.struts</groupId>
<artifactId>struts2-core</artifactId>
<version>2.3.20</version>
</dependency>
<dependency>
<groupId>org.apache.struts</groupId>
<artifactId>struts2-convention-plugin</artifactId>
<version>2.3.20</version>
</dependency>
<dependency>
<groupId>org.apache.struts</groupId>
<artifactId>struts2-json-plugin</artifactId>
<version>2.3.20</version>
</dependency>
</dependencies>
</project>
Output
To run the example, create WAR using maven and deploy it into tomcat. Use below URL to run the application. http://localhost:8080/struts2json-1/jsonWe will get JSON response as
{"result":[{"cities":["Varanasi","Jaunpur","Bhadohi"],"names":["Ram","Shyam","Mohan"]}]}
