对commons fileupload组件的简单封装
<input type="text" name="possess">String possess = request.getParameter("possess") DiskFileItemFactory factory = new DiskFileItemFactory(); //Create a new file upload handler ServletFileUpload upload = new ServletFileUpload(factory); String possess = "";
try {
List items = upload.parseRequest(request); Iterator iterator = items.iterator();
while(iterator.hasNext()){
FileItem item = (FileItem)iterator.next(); if(item.isFormField()){ String fieldName = item.getFieldName(); String value = item.getString(); if(fieldName.equals("possess")){ possess = value;
} } } } catch (FileUploadException e) { e.printStackTrace();
}总体设计思想：
1.我们可以像以前那样，传入控件的name，就可以取得该控件的value，因此我想可以遍历所有FileItem，然后把他们存入一个Map中(key中存入fieldname，value中存入该控件的value)，这样就可以达到以上目的了。
2.在该包装类中，我们还要可以设置一些值，从而我们可以更改commons fileupload中的一些配置。
具体实现： 2.在该包装类中，我们还要可以设置一些值，从而我们可以更改commons fileupload中的一些配置。
根据以上要求，我写出了一个MutiFileUpload类，代码如下，稍后再做详细解释。
package chb.commons.fileupload.web;import java.util.HashMap;import java.util.Iterator;import java.util.List;import java.util.Map;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import org.apache.commons.fileupload.FileItem;import org.apache.commons.fileupload.FileUploadException;import org.apache.commons.fileupload.disk.DiskFileItemFactory;import org.apache.commons.fileupload.servlet.ServletFileUpload;/** * @author chb * */public class MutiFileUpload extends HttpServlet{ private static final long serialVersionUID = 670829239023754119L; protected Map<String, String> parameters;//保存普通form表单域 protected Map<String, FileItem> files;//保存上传的文件 /** * The directory in which uploaded files will be stored, if stored on disk. */ private int sizeThreshold = DiskFileItemFactory.DEFAULT_SIZE_THRESHOLD; /** * The maximum size permitted for the complete request, as opposed to * {@link #fileSizeMax}. A value of -1 indicates no maximum. */ private long sizeMax = -1; private String encoding = "utf-8";//字符编码，当读取上传表单的各部分时会用到该encoding public String getEncoding() { return encoding; } public void setEncoding(String encoding) { this.encoding = encoding; } public long getSizeMax() { return sizeMax; } public void setSizeMax(long sizeMax) { this.sizeMax = sizeMax; } public int getSizeThreshold() { return sizeThreshold; } public void setSizeThreshold(int sizeThreshold) { this.sizeThreshold = sizeThreshold; } public void parse(HttpServletRequest request){ parameters = new HashMap<String, String>(); files = new HashMap<String, FileItem>(); //Create a factory for disk-based file items DiskFileItemFactory factory = new DiskFileItemFactory(); //Set factory constraints factory.setSizeThreshold(sizeThreshold); //factory.setRepository(repository); //Create a new file upload handler ServletFileUpload upload = new ServletFileUpload(factory); //Set overall request size constraint upload.setSizeMax(sizeMax); upload.setHeaderEncoding(encoding); try { List items = upload.parseRequest(request); Iterator iterator = items.iterator(); while(iterator.hasNext()){ FileItem item = (FileItem)iterator.next(); if(item.isFormField()){ String fieldName = item.getFieldName(); String value = item.getString(); parameters.put(fieldName, value); }else{ String fieldName = item.getFieldName(); files.put(fieldName, item); } } } catch (FileUploadException e) { e.printStackTrace(); } } /** 得到上传文件的文件名 * @param item * @return */ public String getFileName(FileItem item){ String fileName = item.getName(); fileName = replace(fileName,"/","/"); fileName = fileName.substring(fileName.lastIndexOf("/")+1); return fileName; } /**字符串替换 * @param source * @param oldString * @param newString * @return */ public static String replace(String source, String oldString, String newString) { StringBuffer output = new StringBuffer(); int lengthOfSource = source.length(); int lengthOfOld = oldString.length(); int posStart = 0; int pos; while ((pos = source.indexOf(oldString, posStart)) >= 0) { output.append(source.substring(posStart, pos)); output.append(newString); posStart = pos + lengthOfOld; } if (posStart < lengthOfSource) { output.append(source.substring(posStart)); } return output.toString(); }}以上代码很简单，看过commons FileUpload组件API的程序员，应该都能看明白。值得注意一下的是：编码问题（setHeaderEncoding），这个方法是从FileUploadBase类里继承的，根据其说明，当读取上传表单的各部分时会用到该encoding，如果没有指定encoding则使用系统缺省的encoding。建议在这里设置成utf-8，并把jsp的charset也设置成utf-8，否则可能会出现乱码。
测试demo
好了，下面我就写个简单的demo吧，说明一下MutiFileUpload的用法。
1.新建一个jsp页面，注意设置form表单的enctype，如下：
<form id="form1" method="post" action="../servlet/UploadServlet" enctype="multipart/form-data"> <tr> <td width="25%" align="right">上传图片：</td> <td> <input id="file1" type="file" NAME="file1" style="300px;"> </td> </tr> <tr> <td width="25%" align="right">上传音频：</td> <td> <input id="file2" type="file" NAME="file2" style="300px;"> </td> </tr> <tr align="center" valign="middle"> <td height="60" colspan="2"> <input type="submit" id="BtnOK" value="确认上传"> <button onclick="javascript:window.opener == null;window.close();">取消上传</button> </td> </tr> <tr align="center" valign="middle"> <td height="60" colspan="2"> <input type="text" name="possess" value="private"> </td> </tr> </form>public class UploadServlet extends MutiFileUpload {} public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { parse(request); System.out.println(parameters.get("possess")); Iterator iterator = files.values().iterator(); while(iterator.hasNext()){ FileItem item = (FileItem) iterator.next(); String fileName = getFileName(item); File file = new File("/root/upload/"+fileName); try { item.write(file); } catch (Exception e) { e.printStackTrace(); } } }好了，先写到这里吧，具体应用时，我们可能需要很多变通，比如集成到spring,hibernate中，关键是给出一个想法，我们可以对他进行包装变更，使其更适合我们的系统。