转自：http://blog.csdn.net/5iasp/article/details/8669644

模拟表单html如下:

java代码如下:

[java] view plain copy

package com.yanek.util;

import java.io.BufferedReader;

import java.io.DataInputStream;

import java.io.DataOutputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.net.HttpURLConnection;

import java.net.URL;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;

import javax.activation.MimetypesFileTypeMap;

import net.sf.json.JSONArray;

import net.sf.json.JSONObject;

public class HttpPostUploadUtil {

/**

* @param args

*/

public static void main(String[] args) {

String filepath="E:\\ziliao\\0.jpg";

String urlStr = "http://127.0.0.1:8080/minicms/up/up_result.jsp";

Map textMap = new HashMap();

textMap.put("name", "testname");

Map fileMap = new HashMap();

fileMap.put("file", filepath);

String ret = formUpload(urlStr, textMap, fileMap);

System.out.println(ret);

}

/**

* 上传图片

*

* @param urlStr

* @param textMap

* @param fileMap

* @return

*/

public static String formUpload(String urlStr, Map textMap,

Map fileMap) {

String res = "";

HttpURLConnection conn = null;

String BOUNDARY = "---------------------------123821742118716"; //boundary就是request头和上传文件内容的分隔符

try {

URL url = new URL(urlStr);

conn = (HttpURLConnection) url.openConnection();

conn.setConnectTimeout(5000);

conn.setReadTimeout(30000);

conn.setDoOutput(true);

conn.setDoInput(true);

conn.setUseCaches(false);

conn.setRequestMethod("POST");

conn.setRequestProperty("Connection", "Keep-Alive");

conn

.setRequestProperty("User-Agent",

"Mozilla/5.0 (Windows; U; Windows NT 6.1; zh-CN; rv:1.9.2.6)");

conn.setRequestProperty("Content-Type",

"multipart/form-data; boundary=" + BOUNDARY);

OutputStream out = new DataOutputStream(conn.getOutputStream());

// text

if (textMap != null) {

StringBuffer strBuf = new StringBuffer();

Iterator iter = textMap.entrySet().iterator();

while (iter.hasNext()) {

Map.Entry entry = (Map.Entry) iter.next();

String inputName = (String) entry.getKey();

String inputValue = (String) entry.getValue();

if (inputValue == null) {

continue;

}

strBuf.append("\r\n").append("--").append(BOUNDARY).append(

"\r\n");

strBuf.append("Content-Disposition: form-data; name=\""

+ inputName + "\"\r\n\r\n");

strBuf.append(inputValue);

}

out.write(strBuf.toString().getBytes());

}

// file

if (fileMap != null) {

Iterator iter = fileMap.entrySet().iterator();

while (iter.hasNext()) {

Map.Entry entry = (Map.Entry) iter.next();

String inputName = (String) entry.getKey();

String inputValue = (String) entry.getValue();

if (inputValue == null) {

continue;

}

File file = new File(inputValue);

String filename = file.getName();

String contentType = new MimetypesFileTypeMap()

.getContentType(file);

if (filename.endsWith(".png")) {

contentType = "image/png";

}

if (contentType == null || contentType.equals("")) {

contentType = "application/octet-stream";

}

StringBuffer strBuf = new StringBuffer();

strBuf.append("\r\n").append("--").append(BOUNDARY).append(

"\r\n");

strBuf.append("Content-Disposition: form-data; name=\""

+ inputName + "\"; filename=\"" + filename

+ "\"\r\n");

strBuf.append("Content-Type:" + contentType + "\r\n\r\n");

out.write(strBuf.toString().getBytes());

DataInputStream in = new DataInputStream(

new FileInputStream(file));

int bytes = 0;

byte[] bufferOut = new byte[1024];

while ((bytes = in.read(bufferOut)) != -1) {

out.write(bufferOut, 0, bytes);

}

in.close();

}

}

byte[] endData = ("\r\n--" + BOUNDARY + "--\r\n").getBytes();

out.write(endData);

out.flush();

out.close();

// 读取返回数据

StringBuffer strBuf = new StringBuffer();

BufferedReader reader = new BufferedReader(new InputStreamReader(

conn.getInputStream()));

String line = null;

while ((line = reader.readLine()) != null) {

strBuf.append(line).append("\n");

}

res = strBuf.toString();

reader.close();

reader = null;

} catch (Exception e) {

System.out.println("发送POST请求出错。" + urlStr);

e.printStackTrace();

} finally {

if (conn != null) {

conn.disconnect();

conn = null;

}

}

return res;

}

}