laxman: How to write our own result type in struts2

How to write our own result type in struts2

Action Class

package com.lkr.action;


import com.lkr.service.UserService;
import com.lkr.vo.User;
import com.opensymphony.xwork2.ActionSupport;


public class GetImageAction extends ActionSupport {


 private static final long serialVersionUID = 1L;
 private UserService userService;
 private Long id;
 private User user;


 public Long getId() {
  return id;
 }


 public void setId(Long id) {
  this.id = id;
 }


 public UserService getUserService() {
  return userService;
 }


 public void setUserService(UserService userService) {
  this.userService = userService;
 }


 @Override
 public String execute() throws Exception {

  System.out.println("this is come from after display image jsp");
  user = userService.getUserById(id);
  return "imageBytesResult";
 }


 public String getContentDisposition() {
  return "";
 }

 public int getBufferSize() {
  return 4096;
 }
}

Result Type Class

package com.lkr.action;


import javax.servlet.http.HttpServletResponse;


import org.apache.struts2.ServletActionContext;


import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.Result;


public class ImageBytesResult implements Result {


 private static final long serialVersionUID = 1L;


 @Override
 public void execute(ActionInvocation invocation) throws Exception {
  GetImageAction action = (GetImageAction) invocation.getAction();
  HttpServletResponse response = ServletActionContext.getResponse();


  //response.setContentType(action.getContentType());
  //response.setContentLength(action.getContentLength());
  response.getOutputStream().write(action.getImageInBytes());
  response.getOutputStream().flush();
 }


}

Service

package com.lkr.service;


import java.util.List;

import com.lkr.dao.UserDAO;
import com.lkr.vo.User;


public class UserService{
 private UserDAO userDao;


 public UserDAO getUserDao() {
  return userDao;
 }


 public void setUserDao(UserDAO userDao) {
  this.userDao = userDao;
 }


 
 public User save(User user) throws Exception {


  return userDao.save(user);
 }



 public List<User> getAllUsers() throws Exception {


  return userDao.getAllUsers();
 }


 
 public User getUserById(long id) throws Exception {
  return userDao.getUserById(id);
 }
}

DAO

package com.lkr.dao;


import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.List;

import org.hibernate.Transaction;

import com.lkr.vo.User;


public class UserDAO {


 
 public User save(User user) throws Exception {
  Transaction tx=getSession().beginTransaction();
  getSession().save(user);
  
  tx.commit();
  return user;
 }


 
 public List<User> getAllUsers() throws Exception {
  List<User> allUsers = getSession().createQuery("from User").list();
  return allUsers;
 }


 
 public User getUserById(long id) throws Exception {
  User user = (User) getSession().get(User.class, new Long(id));
  // Convert BLOB to byte array
  user.setImageInBytes(getImageInBytes(user));
  user.setContentLength((int) user.getImage().length());
  return user;
 }


 public byte[] getImageInBytes(User user) {


  if (user.getImage() == null) {
   return new byte[0];
  }
  ByteArrayOutputStream baos = new ByteArrayOutputStream();
  try {
   InputStream is = user.getImage().getBinaryStream();
   byte[] buf = new byte[1024];
   int i = 0;
   while ((i = is.read(buf)) >= 0) {
    baos.write(buf, 0, i);
   }
   is.close();
  } catch (Exception ex) {
   ex.printStackTrace();
  }
  return baos.toByteArray();
 }
}

struts.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">


<struts>
 <constant name="struts.devMode" value="false" />
 <constant name="struts.custom.i18n.resources" value="global" />
 <constant name="struts.objectFactory" value="spring" />


 <package name="commonPackage" namespace="/" extends="struts-default">


  <result-types>
   <result-type name="imageBytesResult"
    class="com.lkr.action.ImageBytesResult" />
  </result-types>


  <action name="addUserData" class="com.lkr.action.UserAction">
   <result name="input">
    WEB-INF/jsp/imageUploader.jsp
   </result>
  </action>
  <action name="displayFullImage" class="com.lkr.action.FullImageAction">
   <result name="input">
    WEB-INF/jsp/dispalyFullImage.jsp
   </result>
  </action>


  <action name="getImage" class="com.lkr.action.GetImageAction">
   <result name="imageBytesResult" type="imageBytesResult">
   </result>
  </action>
 </package>


</struts>

If you are directly getting Byte[] from the database then you don't need to convert Blob to Byte[]

Jsp:

-----

<!DOCTYPE HTML>
<%@taglib uri="/struts-tags" prefix="s"%>
<html>
<head>
<meta charset="utf-8">
<title>Tracking Gadget - View User</title>
<link href="style.css" rel="stylesheet" type="text/css">
<link rel="stylesheet" href="css/menu.css" type="text/css"
media="screen" charset="utf-8">

</head>
<body>

<div id="content">



<s:form method="post" theme="simple" name="myprofile"
id="myprofile">

<fieldset>
<legend>Licence</legend>
<table width="100%" border="0">
<tr>
<td><img alt="" width="150" height="100"
src="getImage!getImage?id=<s:property value="user.id" />"></td>
</tr>
</table>
</fieldset>

</table> <br />

</s:form>

</div>
</body>
</html>

laxman

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Tuesday, April 17, 2012

How to write our own result type in struts2

How to write our own result type in struts2

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