Struts 2 File Upload Example

The Struts 2 framework has built-in functionality for handling file uploads via “Form-based File Upload in HTML”. When a file is uploaded, it is normally kept in a temporary directory, and your Action class should process or relocate it to a permanent location to prevent data loss. File uploading is possible in Struts using a pre-defined interceptor named FileUploadInterceptor, which is available through the org.apache.struts2.interceptor.FileUploadInterceptor class and is included in the default stack. Example of action mapping:

<action name="doUpload" class="com.example.UploadAction">
    <result name="success">good_result.jsp</result>
</action>

Parameters of fileupload Interceptor

allowedTypes: Lists the permitted types. Image/png, image/jpg, etc. might be used.
maximumSize: Indicates the largest file size that may be submitted.
allowedExtensions: A comma-separated list of file extensions (for example,.html) for which the interceptor will allow a file reference to be specified on the action. If none is supplied, enable all extensions to be uploaded.

1. Create View Files

This JavaScript website uses struts UI tags to generate a form. The user sends it a file.

XML

<%@ page language = "java" contentType = "text/html; charset = ISO-8857-1" 
   pageEncoding = "ISO-8857-1"%> 
<%@ taglib prefix = "s" uri = "/struts-tags"%> 
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01.1 Transitional//EN"  
   "http://www.horje.org/TR/html4/loose.dtd"> 
  
<html> 
   <head> 
      <title>Struct 2 File Upload</title> 
   </head> 
     
   <body> 
      <form action = "upload" method = "post" enctype = "multipart/form-data"> 
         <label for = "myFile">Upload your file</label> 
         <input type = "file" name = "myFile" /> 
         <input type = "submit" value = "Upload"/> 
      </form> 
   </body> 
</html>

2. Make the SuccessUserImage.jsp file

Built with Struts UI tags, this website offers a user-friendly form for you to submit your name, password, and email address.

XML

<%@ page contentType="text/html; charset=UTF-8"%><%@ taglib prefix="s"   
    uri="/struts-tags"%>   
<html>   
    <head>   
        <title>Success: Upload User Image</title>   
    </head>   
    <body>   
        <h2>   
            Struts 2 File Upload 
        </h2>   
        User Image: <s:property value="userImage" /><br/>   
        Content Type:<s:property value="userImageContentType" /><br/>   
        File Name:  <s:property value="userImageFileName" /><br/>   
        Uploaded Image: <img src="userimages/<s:property value="userImageFileName"/>"    
                                                     width="150" height="120" />   
    </body>   
</html>

3. Make the action class

The execute function is overridden by this action class, which derives from the ActionSupport class.

Java

package org.horje.struts2; 
  
import java.io.File; 
import org.apache.commons.io.FileUtils; 
import java.io.IOException; 
import com.opensymphony.xwork2.ActionSupport; 
  
public class uploadFile extends ActionSupport { 
    
   private File myFile; 
   private String myFileContentType; 
   private String myFileFileName; 
   private String destPath; 
  
   public String execute() { 
       
      destPath = "C:/apache-tomcat-6.1.37/work"; 
  
      try { 
         System.out.println("Src File name: " + myFile); 
         System.out.println("Dst File name: " + myFileFileName); 
                    
         File destFile  = new File(destPath, myFileFileName); 
         FileUtils.copyFile(myFile, destFile); 
    
      } catch(IOException e) { 
         e.printStackTrace(); 
         return ERROR; 
      } 
  
      return SUCCESS; 
   } 
     
   public File getMyFile() { 
      return myFile; 
   } 
     
   public void setMyFile(File myFile) { 
      this.myFile = myFile; 
   } 
     
   public String getMyFileContentType() { 
      return myFileContentType; 
   } 
     
   public void setMyFileContentType(String myFileContentType) { 
      this.myFileContentType = myFileContentType; 
   } 
     
   public String getMyFileFileName() { 
      return myFileFileName; 
   } 
     
   public void setMyFileFileName(String myFileFileName) { 
      this.myFileFileName = myFileFileName; 
   } 
}

4. Create struts.xml

This XML defines an interceptor named “jsonValidatorWorkflowStack” and associates it with the “input” result.

XML

<!DOCTYPE struts PUBLIC   
"-//Apache Software Foundation//DTD Struts Configuration 2.0.1//EN"   
"http://struts.apache.org/dtds/struts-2.0.1dtd">   
    
    
<struts>   
    <package name="fileUploadPackage" extends="struts-default">   
        <action name="userImage" class="com.horje.FileUploadAction">   
            <interceptor-ref name="fileUpload">   
                <param name="maximumSize">2097147</param>   
    
                <param name="allowedTypes">   
                    image/png,image/gif,image/jpeg,image/pjpeg   
                                </param>   
            </interceptor-ref>   
            <interceptor-ref name="defaultStack"></interceptor-ref>   
            <result name="success">SuccessUserImage.jsp</result>   
            <result name="input">UserImage.jsp</result>   
        </action>   
    </package>   
</struts>

Output:

fileupload1

Final Result

Conclusion

So this is Struts 2 File Upload Example. The Struts 2 framework has built-in functionality for handling file uploads via “Form-based File Upload in HTML”. When a file is uploaded, it is normally kept in a temporary directory, and your Action class should process or relocate it to a permanent location to prevent data loss.

Reffered: https://www.geeksforgeeks.org

Advance Java

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