List items = upload.parseRequest(request); 为什么items是空的？

lcfsuccess 2009-05-14 10:52:56

代码如下：
FileItemFactory factory = new DiskFileItemFactory();

ServletFileUpload upload = new ServletFileUpload(factory);

List items = upload.parseRequest(request);

Iterator iter = items.iterator();
while (iter.hasNext()) {
FileItem item = (FileItem) iter.next();

//上传文件
if (!item.isFormField()) {
......
......
try{
File uploadedFile = new File(savePath,tempName);

item.write(uploadedFile);
}catch(Exception e){
errorMsg = "上传文件失败。";
}
}
}

为什么程序执行到 List items = upload.parseRequest(request); 后，发现items是空的呢？

请大侠们帮忙分析一下啊。

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jinlin516293816 2011-12-13

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我的解决方案：
Struts2的配置文件加上如下内容：

<constant name="struts.multipart.maxSize" value="1152921504606846970006" />
<constant name="struts.i18n.encoding" value="UTF-8" />
<constant name="struts.multipart.saveDir" value="/tmp" />
<constant name="struts.objectFactory" value="spring" />
<constant name="struts.devMode" value="false" />
<bean type="org.apache.struts2.dispatcher.multipart.MultiPartRequest"
name="myRequestParser" class="com.cn.RequestParseWrapper"
scope="default" optional="true" />
<constant name="struts.multipart.handler" value="myRequestParser" />

标红的这里你要写一个类，这个类的代码哪下所示：

public class RequestParseWrapper extends JakartaMultiPartRequest {

public void parse(HttpServletRequest servletRequest, String saveDir)throws IOException
{

}
｝
虽然这个类什么也没有，但是必须得有。
这样就可以解决 List items = upload.parseRequest(request);它为空的问题了。

启程- 2011-12-06

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22楼和23楼的神人们，解决了吗？要是解决了麻烦加qq指导下啊。万分感谢。 459013614

匿名旅途 2011-12-06

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lcfsuccess
(liuliu)
等　级：
结帖率：0.00%

longhu453226594 2011-08-11

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[Quote=引用 22 楼 csuchenpeng1119 的回复:]

这个是Android客户端上传代码

---------------------------------------------------------------------

package com.chenpeng.prj13;

import java.io.File;
import java.io.FileInputStream;
imp……
[/Quote]

哥们，解决了没？我也遇到此问题，我你的一样，在android开发中.

csuchenpeng1119 2011-04-04

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这个是Android客户端上传代码

---------------------------------------------------------------------

package com.chenpeng.prj13;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

import com.chenpeng.util.Constant;
import com.chenpeng.util.FormFile;
import com.chenpeng.util.HttpFormUtil;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class UploadPicActivity extends Activity{
EditText myEditText1,myEditText2;
Button submitButton,selectButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.upload_pic);
myEditText1=(EditText) findViewById(R.id.picDescEditText);
myEditText2=(EditText) findViewById(R.id.picPathEditText);
submitButton=(Button) findViewById(R.id.submitPicButton);
selectButton=(Button) findViewById(R.id.selectPicButton);
selectButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent=new Intent(UploadPicActivity.this,FileExplorerActivity.class);
//第二个参数为请求码requestCode:1
startActivityForResult(intent, 1);
}
});
submitButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String des=myEditText1.getText().toString().trim();
String actionUrl=myEditText2.getText().toString().trim();
if(uploadFile(actionUrl, des).equals("1")){
showDialog("上传成功!");
}else{
showDialog("上传失敗!");
}
}
});
}
public void showDialog(String msg){
AlertDialog.Builder builder=new AlertDialog.Builder(this);
builder.setMessage(msg).setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
});
AlertDialog ad=builder.create();
ad.show();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
//此处的请求码必须和startActivityForResult中的请求码一致才能接受另一个Activity传递过来的数据
if(requestCode==1){
String path=data.getStringExtra("filepath");
myEditText2.setText(path);
}
}
public String uploadFile(String fileName,String fileDes){
//获取服务器地址
String SERVERPATH=Constant.ServerPath+"/servlet/UploadServlet";
File PicFile=new File(fileName);
FileInputStream picStream;
String result="";
try {
picStream = new FileInputStream(fileName);
Map<String,File> uploadFile=new HashMap<String,File>();
uploadFile.put("uploadPic", PicFile);
byte[] buffer=new byte[picStream.available()];
picStream.read();
FormFile formFile=new FormFile(buffer,fileName,"图片文件","image/gif");
Map<String,String> param=new HashMap<String,String>();
Date d=new Date();
SimpleDateFormat sdf=new SimpleDateFormat("yy-MM-dd HH:mm");
String date=sdf.format(d);
param.put("uploadtime", date);
param.put("filedes", fileDes);
result=HttpFormUtil.post(SERVERPATH, param, uploadFile);
return result;
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
}

-----------------------------------------------------------------------------------

package com.chenpeng.util;

import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Map;

public class HttpFormUtil {
public static String post(String actionUrl,Map<String,String>params,Map<String,File>files) throws Exception{
String BOUNDARY="######"; //分隔符
String PREFIX="--"; //分隔符前后缀
String LINEND="\r\n"; //回车换行
URL url=new URL(actionUrl);
HttpURLConnection conn=(HttpURLConnection) url.openConnection();
conn.setReadTimeout(5*1000);
conn.setDoInput(true); //可以输入
conn.setDoOutput(true); //可以输出
conn.setUseCaches(false); //禁止使用缓存
conn.setRequestMethod("POST"); //请求方法为POST
conn.setRequestProperty("Connection", "Keep-Alive");//连接状态
conn.setRequestProperty("Charset", "UTF-8");
conn.setRequestProperty("ContentType", "multipart/form-data;boundary="+BOUNDARY);//内容类型
StringBuilder sb=new StringBuilder();
//首先组拼文本类型的参数
for(Map.Entry<String,String> entry:params.entrySet()){
sb.append(PREFIX);
sb.append(BOUNDARY);
sb.append(LINEND);
sb.append("Content-Disposition:form-data;name=\""+entry.getKey()+"\""+LINEND);
sb.append("Content-Type:text/plain"+LINEND);
sb.append("Content-Transfer-Encoding:8bit"+LINEND);
sb.append(LINEND);
sb.append(entry.getValue());
sb.append(LINEND);
}
DataOutputStream outputStream=new DataOutputStream(conn.getOutputStream());
outputStream.write(sb.toString().getBytes());
//发送文件数据
if(files!=null){
for(Map.Entry<String,File> file:files.entrySet()){
StringBuilder sb1=new StringBuilder();
sb1.append(PREFIX);
sb1.append(BOUNDARY);
sb1.append(LINEND);
sb1.append("Content-Disposition:form-data;name=\"file\";filename=\""+file.getKey()+"\"");
sb1.append("Content-Type:application/octet-stream;charset=\"UTF-8\""+LINEND);
outputStream.write(sb1.toString().getBytes());
InputStream is=new FileInputStream(file.getValue());
byte[] buffer=new byte[is.available()];
int len=0;
while((len=is.read(buffer))!=-1){
outputStream.write(buffer, 0, len);
}
is.close();
outputStream.write(LINEND.getBytes());
}

//请求结束标志
byte[] end_data=(PREFIX+BOUNDARY+PREFIX+LINEND).getBytes();
outputStream.write(end_data);
outputStream.flush();
//得到响应码
if(conn.getResponseCode()==200){
InputStream in=conn.getInputStream();
byte[] b=new byte[in.available()];
int ch;
if((ch=in.read())!=-1){
sb.append((char)ch);
}
}
}
outputStream.close();
conn.disconnect();
return sb.toString();

}
}

以下是服务器端接收上传文件代码

package Servlet;

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;
import java.util.Iterator;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.FileUpload;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.RequestContext;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.fileupload.servlet.ServletRequestContext;

import vo.UploadFile;

public class UploadServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
// response.setCharacterEncoding("utf-8");
System.out.println("--------------");
PrintWriter out=response.getWriter();
RequestContext req=new ServletRequestContext(request);
FileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
UploadFile uf = new UploadFile();
try {
System.out.println("--------------");
List list = upload.parseRequest(request);
System.out.println("--------------"+list.size());
Iterator it = list.iterator();
while (it.hasNext()) {
FileItem item = (FileItem) it.next();
if (item.isFormField()) {
String fileName = item.getFieldName();
System.out.println(fileName);
if (fileName.equals("uploadtime")) {
uf.setUploadTime(item.getString());
}
if (fileName.equals("filedes")) {
uf.setFileDesc(item.getString());
}
} else {
String fullFileName = item.getName();
int idx = fullFileName.lastIndexOf(".");
String subfix = fullFileName.substring(idx);
String fileName = new Date().getTime() + subfix;
String path = this.getServletContext().getRealPath(
"/upload");
File f = new File(path + "/" + fileName);
item.write(f);
}
}
} catch (Exception e) {
e.printStackTrace();
}
out.print("1");
out.flush();
out.close();
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}
}

希望看过代码后的大侠能够快速给出答复，急急急急急急急急！！！！小弟万分感谢！

csuchenpeng1119 2011-04-04

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有没有高手回答呀？

csuchenpeng1119 2011-04-04

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对呀，我也没有用struts，直接用servlet去接收上传的文件夹，可还是空的，请求高手解释

rockflying 2011-03-28

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我没有用struts，直接用servlet去接收上传的文件夹，可还是空的，请求高手解释

晚风残 2010-12-02

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官方网站上有了：struts2没有解决的办法，struts1可能有。下面是网址
http://commons.apache.org/fileupload/faq.html

hahaizi_liu 2010-11-04

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\过滤时，会改变reqeust的类型，由HttpServletRequest变成MultiPartRequestWrapper

所以parseRequest就返回了null
\

hahaizi_liu 2010-11-04

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各位大哥，我的还是不行啊？web.xml、jsp、action都改成以上说的了，还是空啊！！？？？？？？

love1901 2010-11-03

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mark

qianqian51267 2010-07-21

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struts2过滤时，会改变reqeust的类型，由HttpServletRequest变成MultiPartRequestWrapper

所以parseRequest就返回了null

xiazhilian1987 2010-06-21

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本人用的是struts 1

xiazhilian1987 2010-06-21

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<filter>
<filter-name>EnFilter</filter-name>
<filter-class>com.cnpc.common.EncodingFilter</filter-class>
<init-param>
<param-name>Encoding</param-name>
<param-value>GBK</param-value>
</init-param>
<init-param>
<param-name>OutEncoding</param-name>
<param-value>text/html;charset=GBK</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>EnFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

我也改了*.action 为什么就不行呢那？
谁能解释一哈。万分感谢。

xiaoli19880505 2010-03-14

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难不成过滤器过滤掉了multipart/form-data的请求，应该是吧，吃一垫长一智啊

xiaoli19880505 2010-03-14

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我也遇到了这种情况，为什么7楼的解决就是正确的真是不明白为什么那样就行了

javawang1111 2010-03-03

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跪谢7楼的大哥！太感谢了啊

naiyi1984 2009-12-16

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跪谢7楼的大哥！

jaguarlsl 2009-09-25

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原因就是因为在web.xml中配置了Struts的filter
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

改成

<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>*.action</url-pattern>
</filter-mapping>

就可以了