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
– Aleksandr M, Commented Sep 9, 2014 at 8:07

Community · Accepted Answer · 2017-05-23 11:59:30Z

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, 2017 at 11:59

CommunityBot

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answered Sep 9, 2014 at 9:10

Andrea Ligios

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6 Comments

Karthik Over a year ago

I configured that data in struts.xml using an interceptor.

Andrea Ligios Over a year ago

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.

Karthik Over a year ago

Yes, I tried and got the output. But please don't ask how I got it. I'm still learning it

Andrea Ligios Over a year ago

@Karthik Ok I won't ask :D Please consider accepting and upvoting the answer if it helped, thank you :)

Karthik Over a year ago

It requires 15 reputation.. Which I don't have

|

user1164889 · Accepted Answer · 2014-09-09 08:59:47Z

0

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

answered Sep 9, 2014 at 8:59

user1164889

131 silver badge3 bronze badges

1 Comment

Karthik Over a year ago

Tried that also.. Still same problem

Roman C · Accepted Answer · 2024-03-18 18:19:40Z

0

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.

edited Mar 18, 2024 at 18:19

answered Sep 9, 2014 at 11:25

Roman C

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