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Struts2字典的FileUploadInterceptor 拦截器 主要帮助获取上传文件的ContentType、fileName、文件对象。如果开发人员在开发过程中使用。则需要设置set/get方法：
比如
setXXXContentType()
getXXXFileName()
getXXXContentType()
setXXXFileName()
getXXXFile()
setXXXFile()
其中,"xxx"为渲染器的name.
问题在这里
第一，如果除了ContentType/File/FileName ，还需要其他的消息怎么办呢。拦截器就无能为力了。 这个可以忽略。
第二，平时在开发过程中，我们经常有动态添加附件功能。如果上传的附件同属于一类的话，还尚可。但是，如果一个页面中，需要上传多种类型的附件，而且每个附件类型动态增加的。拦截器就有点力不从心了。只能针对每个类型的附件，在Action中写多个方法。
setType1File();
setType2File();
setType1ContentType();
setType2ContentType();
setType1FileName();
setType2FileName();
---------
问题在这里。如果我再增加一个类型呢？
在深层挖掘一下，如果我想做一个公共的文件上传处理类，怎么办。
本人研究了下自带的拦截器，在此基础上，通过自己的实践，提出自己的一个解决方案。
我通过Map 来管理上传的文件列表。这样就不惧怕多类型文件上传，且可扩展性也提高了。
修正后的Strut2 FileUploadInterceptor 如下
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()}, 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()) {
for (String error : multiWrapper.getErrors()) {
if (validation != null) {
validation.addActionError(error);
}
LOG.warn(error);
}
}
// bind allowed Files
Enumeration fileParameterNames = multiWrapper.getFileParameterNames();
Map<String,List<Map<String,Object>>> fileParameterMap = new HashMap<String,List<Map<String,Object>>>();//文件值对 //zhaogy
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);
List<String> renderNames = 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]);
List<Map<String, Object>> vfl=null;
if(fileParameterMap.containsKey(inputName)){//是否已存在
vfl = fileParameterMap.get(inputName);
}else{
vfl = new ArrayList<Map<String,Object>>();
fileParameterMap.put(inputName, vfl);
}
Map<String, Object> value = new HashMap<String,Object>();
value.put("contentType", contentType[index]);
value.put("fileName", fileName[index]);
value.put("acceptedFile", files[index]);
vfl.add(value);
}
}
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()]));
params.put("fileParameterMap", fileParameterMap);// zhaogy
}
}
} else {
LOG.warn(getTextMessage(action, "struts.messages.invalid.file", new Object[]{inputName}, ac.getLocale()));
}
} else {
LOG.warn(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()) {
if (currentFile.delete() == false) {
LOG.warn("Resource Leaking: Could not remove uploaded file '" + currentFile.getCanonicalPath() + "'.");
}
}
}
}
return result;
}
测试代码：
/*
* $Id: MultipleFileUploadUsingListAction.java 660522 2008-05-27 14:08:00Z jholmes $
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
// START SNIPPET: entire-file
package org.apache.struts2.showcase.fileupload;
import java.io.File;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import com.opensymphony.xwork2.ActionSupport;
/**
* Showcase action - multiple file upload using List
* @version $Date: 2008-05-27 16:08:00 +0200 (Tue, 27 May 2008) $ $Id: MultipleFileUploadUsingListAction.java 660522 2008-05-27 14:08:00Z jholmes $
*/
public class MultipleFileUploadUsingListAction extends ActionSupport {
private List<File> uploads = new ArrayList<File>();
private List<String> uploadFileNames = new ArrayList<String>();
private List<String> uploadContentTypes = new ArrayList<String>();
public void setFileParameterMap(
Map<String, List<Map<String, Object>>> fileParameterMap) {
this.fileParameterMap = fileParameterMap;
}
public List<File> getUpload() {
return this.uploads;
}
public void setUpload(List<File> uploads) {
this.uploads = uploads;
}
public List<String> getUploadFileName() {
return this.uploadFileNames;
}
public void setUploadFileName(List<String> uploadFileNames) {
this.uploadFileNames = uploadFileNames;
}
public List<String> getUploadContentType() {
return this.uploadContentTypes;
}
public void setUploadContentType(List<String> contentTypes) {
this.uploadContentTypes = contentTypes;
}
private Map<String,List<Map<String,Object>>> fileParameterMap;
public Map<String, List<Map<String, Object>>> getFileParameterMap() {
return fileParameterMap;
}
public String upload() throws Exception {
Iterator<String> iter = this.fileParameterMap.keySet().iterator();
while(iter.hasNext()){
String key = iter.next();
List<Map<String, Object>> vs = this.fileParameterMap.get(key);
System.out.println("key========"+key);
for(Map<String, Object> v : vs){
Object contentType = v.get("contentType");
Object fileName = v.get("fileName");
Object file = v.get("acceptedFile");
System.out.println("contentType>>"+contentType);
System.out.println("fileName>>"+fileName);
System.out.println("file>>"+file);
}
}
// System.out.println("\n\n upload1");
// System.out.println("files:");
// for (File u: uploads) {
// System.out.println("*** "+u+"\t"+u.length());
// }
// System.out.println("filenames:");
// for (String n: uploadFileNames) {
// System.out.println("*** "+n);
// }
// System.out.println("content types:");
// for (String c: uploadContentTypes) {
// System.out.println("*** "+c);
// }
// System.out.println("\n\n");
return SUCCESS;
}
}
// END SNIPPET: entire-file
输出
key========upload2
contentType>>application/octet-stream
fileName>>xm_xvs.cfg
file>>D:\Tomcat-6.0.20\work\Catalina\localhost\struts2-showcase\upload_8c1aaae_1372ca9bef5__8000_00000011.tmp
contentType>>text/html
fileName>>login.html
file>>D:\Tomcat-6.0.20\work\Catalina\localhost\struts2-showcase\upload_8c1aaae_1372ca9bef5__8000_00000012.tmp
key========upload
contentType>>text/plain
fileName>>说明.txt
file>>D:\Tomcat-6.0.20\work\Catalina\localhost\struts2-showcase\upload_8c1aaae_1372ca9bef5__8000_00000008.tmp
contentType>>application/vnd.openxmlformats-officedocument.wordprocessingml.document
fileName>>孕妇饮食注意事项.docx
file>>D:\Tomcat-6.0.20\work\Catalina\localhost\struts2-showcase\upload_8c1aaae_1372ca9bef5__8000_00000009.tmp
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