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。
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;
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
private int sizeThreshold = DiskFileItemFactory.DEFAULT_SIZE_THRESHOLD;
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();
}
}
public String getFileName(FileItem item){
String fileName = item.getName();
fileName = replace(fileName,"\\","/");
fileName = fileName.substring(fileName.lastIndexOf("/")+1);
return fileName;
}
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="width:300px;">
</td>
</tr>
<tr>
<td width="25%" align="right">上传音频：</td>
<td>
<input id="file2" type="file" NAME="file2" style="width: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>
2.新建一个UploadServlet并继承自MutiFileUpload，如下：
public class UploadServlet extends MutiFileUpload {
}
3.然后在post方法中如下处理：
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();
}
}
}
选择上传文件，然后我们就可以在/root/upload下看到我们上传的文件了。
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。
