org.apache.struts2.interceptor
public class: FileUploadInterceptor [javadoc |
source]
java.lang.Object
com.opensymphony.xwork2.interceptor.AbstractInterceptor
org.apache.struts2.interceptor.FileUploadInterceptor
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:
- [File Name] : File - the actual File
- [File Name]ContentType : String - the content type of the file
- [File Name]FileName : String - the actual name of the file uploaded (not the HTML name)
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:
- struts.messages.error.uploading - a general error that occurs when the file could not be uploaded
- struts.messages.error.file.too.large - occurs when the uploaded file is too large
- struts.messages.error.content.type.not.allowed - occurs when the uploaded file does not match the expected
content types specified
Interceptor 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.
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.examples.UploadAction">
<interceptor-ref name="fileUpload"/>
<interceptor-ref name="basicStack"/>
<result name="success">good_result.ftl</result>
</action>
And then you need to set encoding
multipart/form-data in the form where the user selects the file to upload.
<a:form action="doUpload" method="post" enctype="multipart/form-data">
<a:file name="upload" label="File"/>
<a:submit/>
</a: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.
public com.examples.UploadAction implemements Action {
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;
}
...
}
| Field Summary |
|---|
| protected static final Log | log | |
| protected Long | maximumSize | |
| protected String | allowedTypes | |
| protected Set | allowedTypesSet | |
| Method from org.apache.struts2.interceptor.FileUploadInterceptor Detail: |
|---|
 protected boolean acceptFile(File file,
String contentType,
String inputName,
ValidationAware validation,
Locale locale) {
boolean fileIsAcceptable = false;
// If it's null the upload failed
if (file == null) {
String errMsg = getTextMessage("struts.messages.error.uploading", new Object[]{inputName}, locale);
if (validation != null) {
validation.addFieldError(inputName, errMsg);
}
log.error(errMsg);
} else if (maximumSize != null && maximumSize.longValue() < file.length()) {
String errMsg = getTextMessage("struts.messages.error.file.too.large", new Object[]{inputName, file.getName(), "" + file.length()}, locale);
if (validation != null) {
validation.addFieldError(inputName, errMsg);
}
log.error(errMsg);
} else if ((! allowedTypesSet.isEmpty()) && (!containsItem(allowedTypesSet, contentType))) {
String errMsg = getTextMessage("struts.messages.error.content.type.not.allowed", new Object[]{inputName, file.getName(), contentType}, locale);
if (validation != null) {
validation.addFieldError(inputName, errMsg);
}
log.error(errMsg);
} else {
fileIsAcceptable = true;
}
return fileIsAcceptable;
}
Override for added functionality. Checks if the proposed file is acceptable based on contentType and size. |
public String intercept(ActionInvocation invocation) throws Exception {
ActionContext ac = invocation.getInvocationContext();
HttpServletRequest request = (HttpServletRequest) ac.get(ServletActionContext.HTTP_REQUEST);
if (!(request instanceof MultiPartRequestWrapper)) {
if (log.isDebugEnabled()) {
ActionProxy proxy = invocation.getProxy();
log.debug(getTextMessage("struts.messages.bypass.request", new Object[]{proxy.getNamespace(), proxy.getActionName()}, ActionContext.getContext().getLocale()));
}
return invocation.invoke();
}
final Object action = invocation.getAction();
ValidationAware validation = null;
if (action instanceof ValidationAware) {
validation = (ValidationAware) action;
}
MultiPartRequestWrapper multiWrapper = (MultiPartRequestWrapper) request;
if (multiWrapper.hasErrors()) {
for (Iterator errorIter = multiWrapper.getErrors().iterator(); errorIter.hasNext();) {
String error = (String) errorIter.next();
if (validation != null) {
validation.addActionError(error);
}
log.error(error);
}
}
Map parameters = ac.getParameters();
// Bind allowed Files
Enumeration fileParameterNames = multiWrapper.getFileParameterNames();
while (fileParameterNames != null && fileParameterNames.hasMoreElements()) {
// get the value of this input tag
String inputName = (String) fileParameterNames.nextElement();
// get the content type
String[] contentType = multiWrapper.getContentTypes(inputName);
if (isNonEmpty(contentType)) {
// get the name of the file from the input tag
String[] fileName = multiWrapper.getFileNames(inputName);
if (isNonEmpty(fileName)) {
// Get a File object for the uploaded File
File[] files = multiWrapper.getFiles(inputName);
if (files != null) {
for (int index = 0; index < files.length; index++) {
if (acceptFile(files[index], contentType[index], inputName, validation, ac.getLocale())) {
parameters.put(inputName, files);
parameters.put(inputName + "ContentType", contentType);
parameters.put(inputName + "FileName", fileName);
}
}
}
} else {
log.error(getTextMessage("struts.messages.invalid.file", new Object[]{inputName}, ActionContext.getContext().getLocale()));
}
} else {
log.error(getTextMessage("struts.messages.invalid.content.type", new Object[]{inputName}, ActionContext.getContext().getLocale()));
}
}
// invoke action
String result = invocation.invoke();
// cleanup
fileParameterNames = multiWrapper.getFileParameterNames();
while (fileParameterNames != null && fileParameterNames.hasMoreElements()) {
String inputValue = (String) fileParameterNames.nextElement();
File[] file = multiWrapper.getFiles(inputValue);
for (int index = 0; index < file.length; index++) {
File currentFile = file[index];
log.info(getTextMessage("struts.messages.removing.file", new Object[]{inputValue, currentFile}, ActionContext.getContext().getLocale()));
if ((currentFile != null) && currentFile.isFile()) {
currentFile.delete();
}
}
}
return result;
} |
public void setAllowedTypes(String allowedTypes) {
this.allowedTypes = allowedTypes;
// set the allowedTypes as a collection for easier access later
allowedTypesSet = getDelimitedValues(allowedTypes);
} Sets the allowed mimetypes |
public void setMaximumSize(Long maximumSize) {
this.maximumSize = maximumSize;
} Sets the maximum size of an uploaded file |
Save This Page