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 & 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)
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.