org.apache.struts2.interceptor
Class FileUploadInterceptor

java.lang.Object
  extended by com.opensymphony.xwork2.interceptor.AbstractInterceptor
      extended by org.apache.struts2.interceptor.FileUploadInterceptor
All Implemented Interfaces:
Interceptor, java.io.Serializable

public class FileUploadInterceptor
extends AbstractInterceptor

Interceptor that is based off of MultiPartRequestWrapper, which is automatically applied for any request that includes a file. It adds the following parameters, where [File Name] is the name given to the file uploaded by the HTML form:

You can get access to these files by merely providing setters in your action that correspond to any of the three patterns above, such as setDocument(File document), setDocumentContentType(String contentType), etc.
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:

Interceptor 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.

Example code:

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

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

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

And then in your action code you'll have access to the File object if you provide setters according to the naming convention documented in the start.

 
    package com.example;
 

import java.io.File; import com.opensymphony.xwork2.ActionSupport;

public UploadAction extends ActionSupport { private File file; private String contentType; private String filename;

public void setUpload(File file) { this.file = file; }

public void setUploadContentType(String contentType) { this.contentType = contentType; }

public void setUploadFileName(String filename) { this.filename = filename; }

public String execute() { //... return SUCCESS; } }

See Also:
Serialized Form

Field Summary
protected  java.util.Set<java.lang.String> allowedExtensionsSet
           
protected  java.util.Set<java.lang.String> allowedTypesSet
           
protected static Logger LOG
           
protected  java.lang.Long maximumSize
           
protected  boolean useActionMessageBundle
           
 
Constructor Summary
FileUploadInterceptor()
           
 
Method Summary
protected  boolean acceptFile(java.lang.Object action, java.io.File file, java.lang.String filename, java.lang.String contentType, java.lang.String inputName, ValidationAware validation, java.util.Locale locale)
          Override for added functionality.
 java.lang.String intercept(ActionInvocation invocation)
           
 void setAllowedExtensions(java.lang.String allowedExtensions)
          Sets the allowed extensions
 void setAllowedTypes(java.lang.String allowedTypes)
          Sets the allowed mimetypes
 void setMatcher(PatternMatcher matcher)
           
 void setMaximumSize(java.lang.Long maximumSize)
          Sets the maximum size of an uploaded file
 void setUseActionMessageBundle(java.lang.String value)
           
 
Methods inherited from class com.opensymphony.xwork2.interceptor.AbstractInterceptor
destroy, init
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

LOG

protected static final Logger LOG

useActionMessageBundle

protected boolean useActionMessageBundle

maximumSize

protected java.lang.Long maximumSize

allowedTypesSet

protected java.util.Set<java.lang.String> allowedTypesSet

allowedExtensionsSet

protected java.util.Set<java.lang.String> allowedExtensionsSet
Constructor Detail

FileUploadInterceptor

public FileUploadInterceptor()
Method Detail

setMatcher

public void setMatcher(PatternMatcher matcher)

setUseActionMessageBundle

public void setUseActionMessageBundle(java.lang.String value)

setAllowedExtensions

public void setAllowedExtensions(java.lang.String allowedExtensions)
Sets the allowed extensions

Parameters:
allowedExtensions - A comma-delimited list of extensions

setAllowedTypes

public void setAllowedTypes(java.lang.String allowedTypes)
Sets the allowed mimetypes

Parameters:
allowedTypes - A comma-delimited list of types

setMaximumSize

public void setMaximumSize(java.lang.Long maximumSize)
Sets the maximum size of an uploaded file

Parameters:
maximumSize - The maximum size in bytes

intercept

public java.lang.String intercept(ActionInvocation invocation)
                           throws java.lang.Exception
Specified by:
intercept in interface Interceptor
Specified by:
intercept in class AbstractInterceptor
Throws:
java.lang.Exception

acceptFile

protected boolean acceptFile(java.lang.Object action,
                             java.io.File file,
                             java.lang.String filename,
                             java.lang.String contentType,
                             java.lang.String inputName,
                             ValidationAware validation,
                             java.util.Locale locale)
Override for added functionality. Checks if the proposed file is acceptable based on contentType and size.

Parameters:
action - - uploading action for message retrieval.
file - - proposed upload file.
contentType - - contentType of the file.
inputName - - inputName of the file.
validation - - Non-null ValidationAware if the action implements ValidationAware, allowing for better logging.
locale -
Returns:
true if the proposed file is acceptable by contentType and size.


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