项目中多处用到文件批量上传功能，今天正好解决了此问题，在此写出来，以便日后借鉴。首先，以下架构下的批量文件上传可能会失败或者不会成功： 1.android客户端+
springMVC服务端：服务端采用org.springframework.web.multipart.MultipartHttpServletRequest作为批量上传接收类，这种搭配下的批量文件上传会失败，最终服务端只会接受到一个文件，即只会接受到第一个文件。可能因为MultipartHttpServletRequest对servlet原本的HttpServletRequest类进行封装，导致批量上传有问题。 2.android客户端+
strutsMVC服务端：这种搭配下的多文件上传，本人没有亲自尝试，不做评论。如果有网友采用此种方式上传失败的，原因可能同1。

接下来说明上传成功的方案： 采用android客户端+
Servlet（HttpServletRequest）进行文件上传。 Servlet端代码如下：

DiskFileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
try {
List items = upload.parseRequest(request);
Iterator itr = items.iterator();
while (itr.hasNext()) {
FileItem item = (FileItem) itr.next();
if (item.isFormField()) {
System.out.println("表单参数名:" + item.getFieldName() + "，表单参数值:" + item.getString("UTF-8"));
}
else {
if (item.getName() != null && !item.getName().equals("")) {
System.out.println("上传文件的大小:" + item.getSize());
System.out.println("上传文件的类型:" + item.getContentType());
// item.getName()返回上传文件在客户端的完整路径名称 System.out.println("上传文件的名称:" + item.getName());
File tempFile = new File(item.getName());
// 上传文件的保存路径 File file = new File(sc.getRealPath("/") + savePath, tempFile.getName());
item.write(file);
request.setAttribute("upload.message", "上传文件成功！");
}
else {
request.setAttribute("upload.message", "没有选择上传文件！");
}
}
}
}
catch (FileUploadException e) {
e.printStackTrace();
}
catch (Exception e) {
e.printStackTrace();
request.setAttribute("upload.message", "上传文件失败！");
}
request.getRequestDispatcher("/uploadResult.jsp").forward(request, response);

android端代码如下：

public class SocketHttpRequester {
/** *多文件上传 * 直接通过HTTP协议提交数据到服务器,实现如下面表单提交功能: *
* @param path 上传路径(注：避免使用localhost或127.0.0.1这样的路径测试，因为它会指向手机模拟器，你可以使用http://www.iteye.cn或http://192.168.1.101:8083这样的路径测试) * @param params 请求参数 key为参数名,value为参数值 * @param file 上传文件 */ public static boolean post(String path, Map params, FormFile[] files) throws Exception{
final String BOUNDARY = "---------------------------7da2137580612";
//数据分隔线 final String endline = "--" + BOUNDARY + "--rn";
//数据结束标志 int fileDataLength = 0;
for(FormFile uploadFile : files){
//得到文件类型数据的总长度 StringBuilder fileExplain = new StringBuilder();
fileExplain.append("--");
fileExplain.append(BOUNDARY);
fileExplain.append("rn");
fileExplain.append("Content-Disposition: form-data;
name=""+ uploadFile.getParameterName()+"";
filename=""+ uploadFile.getFilname() + ""rn");
fileExplain.append("Content-Type: "+ uploadFile.getContentType()+"rnrn");
fileExplain.append("rn");
fileDataLength += fileExplain.length();
if(uploadFile.getInStream()!=null){
fileDataLength += uploadFile.getFile().length();
}
else{
fileDataLength += uploadFile.getData().length;
}
}
StringBuilder textEntity = new StringBuilder();
for (Map.Entry entry : params.entrySet()) {
//构造文本类型参数的实体数据 textEntity.append("--");
textEntity.append(BOUNDARY);
textEntity.append("rn");
textEntity.append("Content-Disposition: form-data;
name=""+ entry.getKey() + ""rnrn");
textEntity.append(entry.getValue());
textEntity.append("rn");
}
//计算传输给服务器的实体数据总长度 int dataLength = textEntity.toString().getBytes().length + fileDataLength + endline.getBytes().length;
URL url = new URL(path);
int port = url.getPort()==-1 ? 80 : url.getPort();
Socket socket = new Socket(InetAddress.getByName(url.getHost()), port);
OutputStream outStream = socket.getOutputStream();
//下面完成HTTP请求头的发送 String requestmethod = "POST "+ url.getPath()+" HTTP/1.1rn";
outStream.write(requestmethod.getBytes());
String accept = "Accept: image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*rn";
outStream.write(accept.getBytes());
String language = "Accept-Language: zh-CNrn";
outStream.write(language.getBytes());
String contenttype = "Content-Type: multipart/form-data;
boundary="+ BOUNDARY+ "rn";
outStream.write(contenttype.getBytes());
String contentlength = "Content-Length: "+ dataLength + "rn";
outStream.write(contentlength.getBytes());
String alive = "Connection: Keep-Alivern";
outStream.write(alive.getBytes());
String host = "Host: "+ url.getHost() +":"+ port +"rn";
outStream.write(host.getBytes());
//写完HTTP请求头后根据HTTP协议再写一个回车换行 outStream.write("rn".getBytes());
//把所有文本类型的实体数据发送出来 outStream.write(textEntity.toString().getBytes());
//把所有文件类型的实体数据发送出来 for(FormFile uploadFile : files){
StringBuilder fileEntity = new StringBuilder();
fileEntity.append("--");
fileEntity.append(BOUNDARY);
fileEntity.append("rn");
fileEntity.append("Content-Disposition: form-data;
name=""+ uploadFile.getParameterName()+"";
filename=""+ uploadFile.getFilname() + ""rn");
fileEntity.append("Content-Type: "+ uploadFile.getContentType()+"rnrn");
outStream.write(fileEntity.toString().getBytes());
if(uploadFile.getInStream()!=null){
byte[] buffer = new byte[1024];
int len = 0;
while((len = uploadFile.getInStream().read(buffer, 0, 1024))!=-1){
outStream.write(buffer, 0, len);
}
uploadFile.getInStream().close();
}
else{
outStream.write(uploadFile.getData(), 0, uploadFile.getData().length);
}
outStream.write("rn".getBytes());
}
//下面发送数据结束标志，表示数据已经结束 outStream.write(endline.getBytes());
BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
if(reader.readLine().indexOf("200")==-1){
//读取web服务器返回的数据，判断请求码是否为200，如果不是200，代表请求失败 return false;
}
outStream.flush();
outStream.close();
reader.close();
socket.close();
return true;
}
/** *单文件上传 * 提交数据到服务器 * @param path 上传路径(注：避免使用localhost或127.0.0.1这样的路径测试，因为它会指向手机模拟器，你可以使用http://www.itcast.cn或http://192.168.1.10:8080这样的路径测试) * @param params 请求参数 key为参数名,value为参数值 * @param file 上传文件 */ public static boolean post(String path, Map params, FormFile file) throws Exception{
return post(path, params, new FormFile[]{
file}
);
}
}

public class FormFile {
/* 上传文件的数据 */ private byte[] data;
private InputStream inStream;
private File file;
private int fileSize;
/* 文件名称 */ private String filname;
/* 请求参数名称*/ private String parameterName;
/* 内容类型 */ private String contentType = "application/octet-stream";
public FormFile(String filname, byte[] data, String parameterName, String contentType) {
this.data = data;
this.filname = filname;
this.parameterName = parameterName;
if(contentType!=null) this.contentType = contentType;
}
public FormFile(String filname, File file, String parameterName, String contentType) {
this.filname = filname;
this.parameterName = parameterName;
this.file = file;
try {
this.inStream = new FileInputStream(file);
}
catch (FileNotFoundException e) {
e.printStackTrace();
}
if(contentType!=null) this.contentType = contentType;
}
public FormFile(InputStream inStream, int fileSize, String filname, String parameterName, String contentType) {
super();
this.inStream = inStream;
this.fileSize = fileSize;
this.filname = filname;
this.parameterName = parameterName;
this.contentType = contentType;
}
public int getFileSize() {
return fileSize;
}
public File getFile() {
return file;
}
public InputStream getInStream() {
return inStream;
}
public byte[] getData() {
return data;
}
public String getFilname() {
return filname;
}
public void setFilname(String filname) {
this.filname = filname;
}
public String getParameterName() {
return parameterName;
}
public void setParameterName(String parameterName) {
this.parameterName = parameterName;
}
public String getContentType() {
return contentType;
}
public void setContentType(String contentType) {
this.contentType = contentType;
}
}

注：以上android端上传代码是从网上借用的，对原作者表示感谢！ 以上代码经本人测试，能正常进行多文件上传。