Uploading image using Struts 2

Question

What I'm trying to do is upload an image using this JSP file :

<%@ page contentType="text/html; charset=UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
 
<html>
  <head>
    <title>Upload User Image</title>
  </head>
 
  <body>
    <h2>Struts2 File Upload &amp; Save Example</h2>
 
    <s:actionerror />
    <s:form action="imageinsert.action" method="post" enctype="multipart/form-data">

      <td>Image : </td><td><input type="file" name="Image"></td> 
      <s:submit value="Upload" align="center" />
    </s:form>
  </body>
</html>

And the action class is as follows :

public class InsertImageBean extends ActionSupport{
   
    private static final long serialVersionUID = 1L;
   
    private File Image;
    private String myFileContentType;
    private String myFileFileName;
   
    public String execute()
    {
        /* Copy file to a safe location */
     
        InsertImage.save(this);

        return SUCCESS;
    }
    public File getMyFile() {
        return Image;
    }
    public void setMyFile(File myFile) {
        this.Image = myFile;
    }
    public String getMyFileContentType() {
        return myFileContentType;
    }
    public void setMyFileContentType(String myFileContentType) {
        this.myFileContentType = myFileContentType;
    }
    public String getMyFileName() {
        return myFileFileName;
    }
    public void setMyFileName(String myFileFileName) {
        this.myFileFileName = myFileFileName;
    }
}

And the bean class is as follows :

public class InsertImage {

    public static int save(InsertImageBean iib) {
        try{
            String filepath = "D:/TEAMWORK/NaTelangana/WebContent/Images";
            File image = iib.getMyFile();
            String myfilename = iib.getMyFileName();
            System.out.println("Src File name: " + iib.getMyFileName());
            System.out.println("Dst File name: " + myfilename);
                     
            File destFile  = new File(filepath, myfilename); // Null pointer exception is thrown here
            FileUtils.copyFile(image, destFile);
            
            System.out.println(System.getProperty("user.dir") );
            
            if(image.renameTo(new File(filepath)))
                System.out.println("File is moved successful!");
            else
                System.out.println("Failed to move!");
        }catch(Exception e){
            e.printStackTrace();
        }
        return 0;
    }
}

Problem is, in the above program I'm getting a NullPointerException in the program above near this line:

File destFile  = new File(filepath, myfilename);

The problem is the input sent is not being received in the bean file. How do I rectify this error ?

This is the error I'm getting :

java.lang.NullPointerException
    at java.io.File.<init>(File.java:317)
    at natelangana.com.InsertImage.save(InsertImage.java:23)
    at bean.com.InsertImageBean.execute(InsertImageBean.java:26)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:440)
    at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:279)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)Src File name: null
Dst File name: null

    at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:163)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:249)
    at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:148)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:93)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:306)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:128)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at org.apache.struts2.interceptor.ProfilingActivationInterceptor.intercept(ProfilingActivationInterceptor.java:104)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:148)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:128)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:306)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
    at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:468)
    at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:395)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)

Your file input name in jsp is `Image` but there is not getter/setter in action class for this name. — Aleksandr M, Sep 09 '14 at 08:07

score 1 · Accepted Answer · edited May 23 '17 at 11:59

1

Change your input name to begin with a lowercase character:
```
<input type="file" name="image">
```

Then in Action you need to prepend the File variable's name to the contentType and FileName Strings, as follows:

private File image;
private String imageContentType;
private String imageFileName;

/* GETTERS AND SETTERS FOR ALL OF THEM */

You may also being interested in how to configure the maximum size for a single file (and for the entire request), allow only certain kind of files to be uploaded, or upload multiple files at once.

EDIT

You didn't post your struts.xml and web.xml configuration, but the line of the stacktrace

at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:395)

unveils that you are using the wrong Filter.

Also the File Upload Interceptor seems to be configured to run twice... and this usually happens when configuring it the wrong way, like

<!-- WRONG  -->
<interceptor-ref name="fileUpload">
    <param name="maximumSize">2097152</param>
    <param name="allowedTypes">
        image/png,image/gif,image/jpeg,image/pjpeg
    </param>            
</interceptor-ref>
<interceptor-ref name="defaultStack" />

instead of

<!-- RIGHT  -->
<interceptor-ref name="defaultStack">
    <param name="fileUpload.maximumSize">2097152</param>
    <param name="fileUpload.allowedTypes">
        image/png,image/gif,image/jpeg,image/pjpeg
    </param>            
</interceptor-ref>

Again, check carefully your configuration both in web.xml and struts.xml, it will work automatically.

edited May 23 '17 at 11:59

Community

1
1

answered Sep 09 '14 at 09:10

Andrea Ligios

49,480
26
114
243

I configured that data in struts.xml using an interceptor. – Karthik Sep 09 '14 at 09:21
Your bean makes no sense; ensure the Action is called, and that it is your `InsertImageBean` action; then check the three variables above, generates their getters and setters automatically, and ensure the value in JSP is changed accordingly. It works, a little bug hunting is the only thing needed. Also ensure you are using an Interceptor Stack containing the upload interceptor, and that everything is configured fine. Using the default one as a test may help. – Andrea Ligios Sep 09 '14 at 10:05
Yes, I tried and got the output. But please don't ask how I got it. I'm still learning it – Karthik Sep 12 '14 at 09:57
@Karthik Ok I won't ask :D Please consider accepting and upvoting the answer if it helped, thank you :) – Andrea Ligios Sep 12 '14 at 09:59
It requires 15 reputation.. Which I don't have – Karthik Sep 12 '14 at 11:24
@Karthik Accepting (marking the white V sign in the top left corner of the answer) doesn't require any reputation. It will instead give you 2 rep points... then you will reach 15 and will gain the privilege to upvote – Andrea Ligios Sep 12 '14 at 11:53

score 0 · Answer 2 · answered Sep 09 '14 at 08:59

0

Try to use <s:file name="Image"/> tag instead of plain <input/>

answered Sep 09 '14 at 08:59

user1164889

13
1
3

Tried that also.. Still same problem – Karthik Sep 09 '14 at 09:05

score 0 · Answer 3 · answered Sep 09 '14 at 11:25

You can start with simple file upload example then you can see where the uploaded file is stored. If you get the uploaded file name is set you can copy file. You can prevent null pointer exception before you start saving.

if (myFileFileName != null)
  InsertImage.save(this);

You can also add required validator that will check the field value before your action is executed.

Uploading image using Struts 2

3 Answers3

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