java模拟表单上传文件，java通过模拟post方式提交表单实现图片上传功能实例

java模拟表单上传文件，java通过模拟post方式提交表单实现图片上传功能实例
HttpClient 测试类，提供get post方法实例

 package com.zdz.httpclient;

 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;

 /**
  * java通过模拟post方式提交表单实现图片上传功能实例
  * 其他文件类型可以传入 contentType 实现
  * @author zdz8207
  * {@link http://www.cnblogs.com/zdz8207/}
  * @version 1.0
  */
 public class HttpUploadFile {

     public static void main(String[] args) {
         testUploadImage();
     }

     /**
      * 测试上传png图片
      *
      */
     public static void testUploadImage(){
         String url = "http://xxx/wnwapi/index.php/Api/Index/testUploadModelBaking";
         String fileName = "e:/chenjichao/textures/antimap_0017.png";
         Map<String, String> textMap = new HashMap<String, String>();
         //可以设置多个input的name，value
         textMap.put("name", "testname");
         textMap.put("type", "2");
         //设置file的name，路径
         Map<String, String> fileMap = new HashMap<String, String>();
         fileMap.put("upfile", fileName);
         String contentType = "";//image/png
         String ret = formUpload(url, textMap, fileMap,contentType);
         System.out.println(ret);
         //{"status":"0","message":"add succeed","baking_url":"group1\/M00\/00\/A8\/CgACJ1Zo-LuAN207AAQA3nlGY5k151.png"}
     }

     /**
      * 上传图片
      * @param urlStr
      * @param textMap
      * @param fileMap
      * @param contentType 没有传入文件类型默认采用application/octet-stream
      * contentType非空采用filename匹配默认的图片类型
      * @return 返回response数据
      */
     @SuppressWarnings("rawtypes")
     public static String formUpload(String urlStr, Map<String, String> textMap,
             Map<String, String> fileMap,String contentType) {
         String res = "";
         HttpURLConnection conn = null;
         // boundary就是request头和上传文件内容的分隔符
         String BOUNDARY = "---------------------------123821742118716";
         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();

                     //没有传入文件类型，同时根据文件获取不到类型，默认采用application/octet-stream
                     contentType = new MimetypesFileTypeMap().getContentType(file);
                     //contentType非空采用filename匹配默认的图片类型
                     if(!"".equals(contentType)){
                         if (filename.endsWith(".png")) {
                             contentType = "image/png";
                         }else if (filename.endsWith(".jpg") || filename.endsWith(".jpeg") || filename.endsWith(".jpe")) {
                             contentType = "image/jpeg";
                         }else if (filename.endsWith(".gif")) {
                             contentType = "image/gif";
                         }else if (filename.endsWith(".ico")) {
                             contentType = "image/image/x-icon";
                         }
                     }
                     if (contentType == null || "".equals(contentType)) {
                         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;
     }
 }

HttpClientTest.java

package com.zdz.httpclient;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.NameValuePair;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.methods.PostMethod;

/**
 * HttpClient 测试类，提供get post方法实例
 * @author zdz8207
 *
 */
public class HttpClientTest {
    private static final String URL = "http://www.163.com";
    private static final int PORT = 80;

    public static void main(String[] args) throws Exception {
        //测试get方法
        doGetMethod(URL,PORT);
        //测试post方法
        String posturl = "http://mail.163.com/";
        doPostMethod(posturl,PORT);
    }

    /**
     * http get 方法
     * @param url
     * @param port
     * @throws HttpException
     * @throws IOException
     * @return bodystring
     */
    public static String doGetMethod(String url,int port) throws HttpException, IOException {
        HttpClient client = new HttpClient();
        // 设置代理服务器地址和端口
        client.getHostConfiguration().setHost(url, port);
        // 使用 GET 方法
        GetMethod method = new GetMethod(url);
        //执行请求
        client.executeMethod(method);

        // 打印服务器返回的状态
        System.out.println(method.getStatusLine());
        // 打印返回的信息
//        System.out.println(method.getResponseBodyAsString());
        // response body of large or unknown size. Using getResponseBodyAsStream instead is recommended.
        InputStream bodystreams = method.getResponseBodyAsStream();
        String body = convertStreamToString(bodystreams);
        System.out.println(body);
        // 释放连接
        method.releaseConnection();

        return body;
    }

    /**
     * http post 方法
     * @param url
     * @param port
     * @throws HttpException
     * @throws IOException
     * @return bodystring
     */
    public static String doPostMethod(String url,int port) throws HttpException, IOException {
        HttpClient client = new HttpClient();
        // 设置代理服务器地址和端口
        client.getHostConfiguration().setHost(url, port);
        // 使用POST方法
        PostMethod method = new PostMethod(url);
        //设置传递参数
        NameValuePair agent = new NameValuePair("User-Agent","Mozilla/4.0 (compatible; MSIE 8.0; Windows 2000)");
        NameValuePair username = new NameValuePair("email", "xxx@163.com");
        NameValuePair password = new NameValuePair("password", "xxxxxx");
        method.setRequestBody(new NameValuePair[] { agent, username, password });
        //执行请求
        client.executeMethod(method);
//        设置cookies
//        Cookie[] cookies = client.getState().getCookies();
//        client.getState().addCookies(cookies);

        // 打印服务器返回的状态
        System.out.println(method.getStatusLine());
        // 打印返回的信息
//        System.out.println(method.getResponseBodyAsString());
        // response body of large or unknown size. Using getResponseBodyAsStream instead is recommended.
        InputStream bodystreams = method.getResponseBodyAsStream();
        String body = convertStreamToString(bodystreams);
        System.out.println(body);
        // 释放连接
        method.releaseConnection();

        return body;
    }

    /**
     * 把InputStream 转换成String返回
     * @param is InputStream
     * @return String
     * @throws UnsupportedEncodingException
     */
    public static String convertStreamToString(InputStream is) throws UnsupportedEncodingException {
//        BufferedReader reader = new BufferedReader(new InputStreamReader(is));//输出的中文乱码
        BufferedReader reader = new BufferedReader(new InputStreamReader(is,"utf8")); //GBK
        StringBuilder sb = new StringBuilder();
        String line = null;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
               e.printStackTrace();
            }
        }
        return sb.toString();
    }

}

项目实例下载地址（包括对应jar包）

ps:New text file line delimiter选择不同导致控制台输出编码不同,如下图所示：