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:
struts.messages.error.uploading
- a general error that occurs when the file could not be uploadedstruts.messages.error.file.too.large
- occurs when the uploaded file is too largestruts.messages.error.content.type.not.allowed
- occurs when the uploaded file does not match the expected content types specifiedstruts.messages.error.file.extension.not.allowed
- occurs when the uploaded file does not match the expected file extensions specified
Parameters
maximumSize
(optional) - the maximum size (in bytes) that the interceptor will allow a file reference to be set on the action. Note, this is not related to the various properties found in struts.properties. Default to approximately 2MB.allowedTypes
(optional) - a comma separated list of content types (ie:text/html
) that the interceptor will allow a file reference to be set on the action. If none is specified allow all types to be uploaded.allowedExtensions
(optional) - a comma separated list of file extensions (ie:.html
) that the interceptor will allow a file reference to be set on the action. If none is specified allow all extensions to be uploaded.
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.