java模擬post方式提交表單實現圖片上傳

模擬表單html如下:

<form action="up_result.jsp" method="post" enctype="multipart/form-data" name="form1" id="form1">
 
    <label>
  <input type="text" name="name" value="" />
  </label>
 
    <label>
  <input type="file" name="userfile" />
  </label>
 
  <label>
  <input type="submit" value="上傳" />
  </label>
</form>

java代碼如下:

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<String, String> textMap = new HashMap<String, String>();  

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

        Map<String, String> fileMap = new HashMap<String, String>();  

        fileMap.put("userfile", filepath);  

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

        System.out.println(ret);  


    }  



    /** 
     * 上傳圖片 
     *  
     * @param urlStr 
     * @param textMap 
     * @param fileMap 
     * @return 
     */  
    public static String formUpload(String urlStr, Map<String, String> textMap,  
            Map<String, String> fileMap) {  
        String res = "";  
        HttpURLConnection conn = null;  
        String BOUNDARY = "---------------------------123821742118716"; //boundary就是request頭和上傳文件內容的分隔符  
        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();  

            // 讀取返回數據  
            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("發送POST請求出錯。" + urlStr);  
            e.printStackTrace();  
        } finally {  
            if (conn != null) {  
                conn.disconnect();  
                conn = null;  
            }  
        }  
        return res;  
    }  

}