java实现利用HTTP基于servlet上传文件至服务器

Java客户端程序fileupload.java

import java.io.DataOutputStream;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStream;

import https://www.360docs.net/doc/c9102474.html,.HttpURLConnection;

import https://www.360docs.net/doc/c9102474.html,.URL;

public class fileupload {

public static String upload(String actionUrl,String FileName)throws IOException{

String BOUNDARY = java.util.UUID.randomUUID().toString();

String PREFFIX = "--", LINEND = "\r\n";

String MULTIPART_FROM_DATA = "multipart/form-data";

String CHARSET = "UTF-8";

URL uri = new URL(actionUrl);

HttpURLConnection conn = (HttpURLConnection) uri.openConnection();// 设置从主机读取数据超时

conn.setReadTimeout(10 * 1000);

conn.setDoInput(true);

conn.setDoOutput(true);

conn.setUseCaches(false);

conn.setRequestMethod("POST");

conn.setRequestProperty("connection", "keep-alive");

conn.setRequestProperty("Charset", "UTF-8");

conn.setRequestProperty("Content-Type", MULTIPART_FROM_DATA + ";boundary=" + BOUNDARY);

DataOutputStream outStream = new DataOutputStream(

conn.getOutputStream());

if (FileName != null) {

// 构建发送字符串数据

StringBuilder sb1 = new StringBuilder();

sb1.append(PREFFIX);

sb1.append(BOUNDARY);

sb1.append(LINEND);

sb1.append("Content-Disposition: form-data; name=\"file\"; filename=\""

+ FileName + "\"" + LINEND);

sb1.append("Content-Type: application/octet-stream;chartset="

+ CHARSET + LINEND);

sb1.append(LINEND);

// 写入到输出流中

outStream.write(sb1.toString().getBytes());

// 将文件读入输入流中

InputStream is = new FileInputStream(FileName);

byte[] buffer = new byte[1024];

int len = 0;

// 写入输出流

while ((len = is.read(buffer)) != -1) {

outStream.write(buffer, 0, len);

}

is.close();

// 添加换行标志

outStream.write(LINEND.getBytes());

}

// 请求结束标志

byte[] end_data = (PREFFIX + BOUNDARY + PREFFIX + LINEND).getBytes();

outStream.write(end_data);

// 刷新发送数据

outStream.flush();

// 得到响应码

int res = conn.getResponseCode();

//System.out.println(res);

InputStream in = null;

// 上传成功返回200

if (res == 200) {

in = conn.getInputStream();

int ch;

StringBuilder sb2 = new StringBuilder();

// 保存数据

while ((ch = in.read()) != -1) {

sb2.append((char) ch);

}

}

// 如果数据不为空，则以字符串方式返回数据，否则返回null

return in == null ? null : in.toString();

}

}

在web.xml中配置Servlet

MyServlet

umb.load.Fileupload

MyServlet

/upload/*

服务器端程序Fileupload.java

package umb.load;

import java.io.File;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.Iterator;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import https://www.360docs.net/doc/c9102474.html,mons.fileupload.FileItem;

import https://www.360docs.net/doc/c9102474.html,mons.fileupload.FileItemFactory;

import https://www.360docs.net/doc/c9102474.html,mons.fileupload.disk.DiskFileItemFactory;

import https://www.360docs.net/doc/c9102474.html,mons.fileupload.servlet.ServletFileUpload;

@SuppressWarnings("serial")

public class Fileupload extends HttpServlet{

public void doPost(HttpServletRequest request,HttpServletResponse response)throws IOException, ServletException{

boolean isMultipart = ServletFileUpload.isMultipartContent(request);

if (isMultipart) {

FileItemFactory factory = new DiskFileItemFactory();

ServletFileUpload upload = new ServletFileUpload(factory);

@SuppressWarnings("rawtypes")

Iterator items;

try {

items = upload.parseRequest(request).iterator();

while (items.hasNext()) {

FileItem item = (FileItem) items.next();

if (!item.isFormField()) {

//取出上传文件的文件名称

String name = item.getName();

//System.out.println(name);

String fileName =

name.substring(https://www.360docs.net/doc/c9102474.html,stIndexOf('\\')+1,name.length());

//System.out.println(fileName);

String path =

request.getRealPath("upload")+File.separatorChar+fileName;

//上传文件

File uploadedFile = new File(path);

item.write(uploadedFile);

response.setContentType("text/html;charset=gb2312");

PrintWriter out = response.getWriter();

//System.out.println(path);

out.print("上传的文件为："+name+"
");

out.print("保存的地址为："+path+"");

}

}

} catch (Exception e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

}