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Action File Upload Interceptor

Available since Struts 6.4.0 as replacement for File Upload Interceptor

See this page for more examples and advanced configuration.

Interceptor that is based off of MultiPartRequestWrapper, which is automatically applied for any request that includes a file. If an action implements org.apache.struts2.action.UploadedFilesAware interface, the interceptor will pass information and content of uploaded files using the callback method withUploadedFiles(List<UploadedFile>).

See the example code section.

This interceptor will add several field errors, assuming that the action implements ValidationAware. These error messages are based on several i18n values stored in struts-messages.properties, a default i18n file processed for all i18n requests. You can override the text of these messages by providing text for the following keys:

Parameters

Extending the Interceptor

You can extend this interceptor and override the acceptFile method to provide more control over which files are supported and which are not.

Examples

See this page for more examples and advanced configuration.

Example action mapping:

 <action name="doUpload" class="com.example.UploadAction">
     <interceptor-ref name="actionFileUpload"/>
     <interceptor-ref name="basicStack"/>
     <result name="success">good_result.jsp</result>
 </action>

Notice the interceptor configuration in the preceding example.

Example JSP form tags:

   <s:form action="doUpload" method="post" enctype="multipart/form-data">
       <s:file name="upload" label="File"/>
       <s:submit/>
   </s:form>

You must set the encoding to multipart/form-data in the form where the user selects the file to upload.

Example Action class:

public class UploadAction extends ActionSupport implements UploadedFilesAware {
   private UploadedFile uploadedFile;
   private String contentType;
   private String fileName;
   private String originalName;

   @Override
   public void withUploadedFiles(List<UploadedFile> uploadedFiles) {
      if (!uploadedFiles.isEmpty()) {
         this.uploadedFile = uploadedFiles.get(0);
         this.fileName = uploadedFile.getName();
         this.contentType = uploadedFile.getContentType();
         this.originalName = uploadedFile.getOriginalName();
      }
   }

   public String execute() {
      //do something with the file
      return SUCCESS;
   }
}

Setting parameters example:

<interceptor-ref name="fileUpload">
  <param name="allowedTypes">
     image/png,image/gif,image/jpeg
  </param>
</interceptor-ref>

This part is optional and would be done in place of the <interceptor-ref name="actionFileUpload"/> line in the action mapping example above.