您提供的解决方案并不完全正确，如果我想要严格的上传限制以及 i18n，这将不起作用。为此，我还为 strut2 创建了一个问题。请查看以下链接https://issues.apache.org/jira/browse/WW-3177。它应该在 struts2.1.9 中修复，并且已经分配给一个 struts 团队成员。
在这两者之间，我正在使用 hack。我浏览了struts2的源代码，找到了FileUploadInterceptor的代码。使用该代码，我创建了自己的代码。这是下面的代码。您可以在上面的链接中找到问题的详细信息。希望这会有所帮助。
import java.io.File;
import java.util.*;
import javax.servlet.http.HttpServletRequest;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.dispatcher.multipart.MultiPartRequestWrapper;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.ActionProxy;
import com.opensymphony.xwork2.ValidationAware;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;
import com.opensymphony.xwork2.util.LocalizedTextUtil;
import com.opensymphony.xwork2.util.TextParseUtil;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;
public class CustomFileUploaderInterceptor extends AbstractInterceptor {
private static final long serialVersionUID = -4764627478894962478L;
protected static final Logger LOG = LoggerFactory.getLogger(CustomFileUploaderInterceptor.class);
private static final String DEFAULT_MESSAGE = "no.message.found";
protected boolean useActionMessageBundle;
protected Long maximumSize;
protected Set<String> allowedTypesSet = Collections.emptySet();
protected Set<String> allowedExtensionsSet = Collections.emptySet();
public void setUseActionMessageBundle(String value) {
this.useActionMessageBundle = Boolean.valueOf(value);
}
/**
* Sets the allowed extensions
*
* @param allowedExtensions A comma-delimited list of extensions
*/
public void setAllowedExtensions(String allowedExtensions) {
allowedExtensionsSet = TextParseUtil.commaDelimitedStringToSet(allowedExtensions);
}
/**
* Sets the allowed mimetypes
*
* @param allowedTypes A comma-delimited list of types
*/
public void setAllowedTypes(String allowedTypes) {
allowedTypesSet = TextParseUtil.commaDelimitedStringToSet(allowedTypes);
}
/**
* Sets the maximum size of an uploaded file
*
* @param maximumSize The maximum size in bytes
*/
public void setMaximumSize(Long maximumSize) {
this.maximumSize = maximumSize;
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.interceptor.Interceptor#intercept(com.opensymphony.xwork2.ActionInvocation)
*/
public String intercept(ActionInvocation invocation) throws Exception {
ActionContext ac = invocation.getInvocationContext();
Map<String, Object> params1 = ac.getParameters();
Set<String> keySet = params1.keySet();
for(String s : keySet){
LOG.debug("Key: "+ s +", Value: " + params1.get(s).toString());
}
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()}, ac.getLocale()));
}
return invocation.invoke();
}
ValidationAware validation = null;
Object action = invocation.getAction();
if (action instanceof ValidationAware) {
validation = (ValidationAware) action;
}
MultiPartRequestWrapper multiWrapper = (MultiPartRequestWrapper) request;
if (multiWrapper.hasErrors()) {
String inputName = null;
if(multiWrapper.getFileParameterNames().hasMoreElements()){
inputName = (String)multiWrapper.getFileParameterNames().nextElement();
}
for (String error : multiWrapper.getErrors()) {
if (validation != null) {
Object[] args = new Object[]{inputName};
validation.addActionError(getTextMessage(action, "struts.messages.error.file.too.large", args, ac.getLocale()));
}
LOG.error(error);
}
}
// 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 && files.length > 0) {
List<File> acceptedFiles = new ArrayList<File>(files.length);
List<String> acceptedContentTypes = new ArrayList<String>(files.length);
List<String> acceptedFileNames = new ArrayList<String>(files.length);
String contentTypeName = inputName + "ContentType";
String fileNameName = inputName + "FileName";
for (int index = 0; index < files.length; index++) {
if (acceptFile(action, files[index], fileName[index], contentType[index], inputName, validation, ac.getLocale())) {
acceptedFiles.add(files[index]);
acceptedContentTypes.add(contentType[index]);
acceptedFileNames.add(fileName[index]);
}
}
if (!acceptedFiles.isEmpty()) {
Map<String, Object> params = ac.getParameters();
params.put(inputName, acceptedFiles.toArray(new File[acceptedFiles.size()]));
params.put(contentTypeName, acceptedContentTypes.toArray(new String[acceptedContentTypes.size()]));
params.put(fileNameName, acceptedFileNames.toArray(new String[acceptedFileNames.size()]));
}
}
} else {
LOG.error(getTextMessage(action, "struts.messages.invalid.file", new Object[]{inputName}, ac.getLocale()));
}
} else {
LOG.error(getTextMessage(action, "struts.messages.invalid.content.type", new Object[]{inputName}, ac.getLocale()));
}
}
// invoke action
String result = invocation.invoke();
// cleanup
fileParameterNames = multiWrapper.getFileParameterNames();
while (fileParameterNames != null && fileParameterNames.hasMoreElements()) {
String inputValue = (String) fileParameterNames.nextElement();
File[] files = multiWrapper.getFiles(inputValue);
for (File currentFile : files) {
if (LOG.isInfoEnabled()) {
LOG.info(getTextMessage(action, "struts.messages.removing.file", new Object[]{inputValue, currentFile}, ac.getLocale()));
}
if ((currentFile != null) && currentFile.isFile()) {
currentFile.delete();
}
}
}
return result;
}
/**
* Override for added functionality. Checks if the proposed file is acceptable based on contentType and size.
*
* @param action - uploading action for message retrieval.
* @param file - proposed upload file.
* @param contentType - contentType of the file.
* @param inputName - inputName of the file.
* @param validation - Non-null ValidationAware if the action implements ValidationAware, allowing for better
* logging.
* @param locale
* @return true if the proposed file is acceptable by contentType and size.
*/
protected boolean acceptFile(Object action, File file, String filename, String contentType, String inputName, ValidationAware validation, Locale locale) {
boolean fileIsAcceptable = false;
// If it's null the upload failed
if (file == null) {
String errMsg = getTextMessage(action, "struts.messages.error.uploading", new Object[]{inputName}, locale);
if (validation != null) {
validation.addFieldError(inputName, errMsg);
}
LOG.error(errMsg);
} else if (maximumSize != null && maximumSize < file.length()) {
String errMsg = getTextMessage(action, "struts.messages.error.file.too.large", new Object[]{inputName, filename, 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(action, "struts.messages.error.content.type.not.allowed", new Object[]{inputName, filename, file.getName(), contentType}, locale);
if (validation != null) {
validation.addFieldError(inputName, errMsg);
}
LOG.error(errMsg);
} else if ((! allowedExtensionsSet.isEmpty()) && (!hasAllowedExtension(allowedExtensionsSet, filename))) {
String errMsg = getTextMessage(action, "struts.messages.error.file.extension.not.allowed", new Object[]{inputName, filename, file.getName(), contentType}, locale);
if (validation != null) {
validation.addFieldError(inputName, errMsg);
}
LOG.error(errMsg);
} else {
fileIsAcceptable = true;
}
return fileIsAcceptable;
}
/**
* @param extensionCollection - Collection of extensions (all lowercase).
* @param filename - filename to check.
* @return true if the filename has an allowed extension, false otherwise.
*/
private static boolean hasAllowedExtension(Collection<String> extensionCollection, String filename) {
if (filename == null) {
return false;
}
String lowercaseFilename = filename.toLowerCase();
for (String extension : extensionCollection) {
if (lowercaseFilename.endsWith(extension)) {
return true;
}
}
return false;
}
/**
* @param itemCollection - Collection of string items (all lowercase).
* @param item - Item to search for.
* @return true if itemCollection contains the item, false otherwise.
*/
private static boolean containsItem(Collection<String> itemCollection, String item) {
return itemCollection.contains(item.toLowerCase());
}
private static boolean isNonEmpty(Object[] objArray) {
boolean result = false;
for (int index = 0; index < objArray.length && !result; index++) {
if (objArray[index] != null) {
result = true;
}
}
return result;
}
private String getTextMessage(String messageKey, Object[] args, Locale locale) {
return getTextMessage(null, messageKey, args, locale);
}
private String getTextMessage(Object action, String messageKey, Object[] args, Locale locale) {
if (args == null || args.length == 0) {
if ( action != null && useActionMessageBundle) {
return LocalizedTextUtil.findText(action.getClass(), messageKey, locale);
}
return LocalizedTextUtil.findText(this.getClass(), messageKey, locale);
} else {
if ( action != null && useActionMessageBundle) {
return LocalizedTextUtil.findText(action.getClass(), messageKey, locale, DEFAULT_MESSAGE, args);
}
return LocalizedTextUtil.findText(this.getClass(), messageKey, locale, DEFAULT_MESSAGE, args);
}
}
}