Android使用post方式上传图片到服务器的方法

本文实例讲述了android使用post方式上传图片到服务器的方法。分享给大家供大家参考，具体如下：

/**
 * 上传文件到服务器类
 * 
 * @author tom
 */
public class uploadutil {
  private static final string tag = "uploadfile";
  private static final int time_out = 10 * 1000; // 超时时间
  private static final string charset = "utf-8"; // 设置编码
  /**
   * android上传文件到服务端
   * 
   * @param file 需要上传的文件
   * @param requesturl 请求的rul
   * @return 返回响应的内容
   */
  public static string uploadfile(file file, string requesturl) {
    string result = null;
    string boundary = uuid.randomuuid().tostring(); // 边界标识 随机生成
    string prefix = "--", line_end = "\r\n";
    string content_type = "multipart/form-data"; // 内容类型
    try {
      url url = new url(requesturl);
      httpurlconnection conn = (httpurlconnection) url.openconnection();
      conn.setreadtimeout(time_out);
      conn.setconnecttimeout(time_out);
      conn.setdoinput(true); // 允许输入流
      conn.setdooutput(true); // 允许输出流
      conn.setusecaches(false); // 不允许使用缓存
      conn.setrequestmethod("post"); // 请求方式
      conn.setrequestproperty("charset", charset); // 设置编码
      conn.setrequestproperty("connection", "keep-alive");
      conn.setrequestproperty("content-type", content_type + ";boundary=" + boundary);
      if (file != null) {
        /**
         * 当文件不为空，把文件包装并且上传
         */
        dataoutputstream dos = new dataoutputstream(conn.getoutputstream());
        stringbuffer sb = new stringbuffer();
        sb.append(prefix);
        sb.append(boundary);
        sb.append(line_end);
        /**
         * 这里重点注意： name里面的值为服务端需要key 只有这个key 才可以得到对应的文件
         * filename是文件的名字，包含后缀名的 比如:abc.png
         */
        sb.append("content-disposition: form-data; name=\"uploadfile\"; filename=\""
            + file.getname() + "\"" + line_end);
        sb.append("content-type: application/octet-stream; charset=" + charset + line_end);
        sb.append(line_end);
        dos.write(sb.tostring().getbytes());
        inputstream is = new fileinputstream(file);
        byte[] bytes = new byte[1024];
        int len = 0;
        while ((len = is.read(bytes)) != -1) {
          dos.write(bytes, 0, len);
        }
        is.close();
        dos.write(line_end.getbytes());
        byte[] end_data = (prefix + boundary + prefix + line_end).getbytes();
        dos.write(end_data);
        dos.flush();
        /**
         * 获取响应码 200=成功 当响应成功，获取响应的流
         */
        int res = conn.getresponsecode();
        log.e(tag, "response code:" + res);
        // if(res==200)
        // {
        log.e(tag, "request success");
        inputstream input = conn.getinputstream();
        stringbuffer sb1 = new stringbuffer();
        int ss;
        while ((ss = input.read()) != -1) {
          sb1.append((char) ss);
        }
        result = sb1.tostring();
        log.e(tag, "result : " + result);
        // }
        // else{
        // log.e(tag, "request error");
        // }
      }
    } catch (malformedurlexception e) {
      e.printstacktrace();
    } catch (ioexception e) {
      e.printstacktrace();
    }
    return result;
  }
  /**
   * 通过拼接的方式构造请求内容，实现参数传输以及文件传输
   * 
   * @param url service net address
   * @param params text content
   * @param files pictures
   * @return string result of service response
   * @throws ioexception
   */
  public static string post(string url, map<string, string> params, map<string, file> files)
      throws ioexception {
    string boundary = java.util.uuid.randomuuid().tostring();
    string prefix = "--", linend = "\r\n";
    string multipart_from_data = "multipart/form-data";
    string charset = "utf-8";
    url uri = new url(url);
    httpurlconnection conn = (httpurlconnection) uri.openconnection();
    conn.setreadtimeout(10 * 1000); // 缓存的最长时间
    conn.setdoinput(true);// 允许输入
    conn.setdooutput(true);// 允许输出
    conn.setusecaches(false); // 不允许使用缓存
    conn.setrequestmethod("post");
    conn.setrequestproperty("connection", "keep-alive");
    conn.setrequestproperty("charsert", "utf-8");
    conn.setrequestproperty("content-type", multipart_from_data + ";boundary=" + boundary);
    // 首先组拼文本类型的参数
    stringbuilder sb = new stringbuilder();
    for (map.entry<string, string> entry : params.entryset()) {
      sb.append(prefix);
      sb.append(boundary);
      sb.append(linend);
      sb.append("content-disposition: form-data; name=\"" + entry.getkey() + "\"" + linend);
      sb.append("content-type: text/plain; charset=" + charset + linend);
      sb.append("content-transfer-encoding: 8bit" + linend);
      sb.append(linend);
      sb.append(entry.getvalue());
      sb.append(linend);
    }
    dataoutputstream outstream = new dataoutputstream(conn.getoutputstream());
    outstream.write(sb.tostring().getbytes());
    // 发送文件数据
    if (files != null)
      for (map.entry<string, file> file : files.entryset()) {
        stringbuilder sb1 = new stringbuilder();
        sb1.append(prefix);
        sb1.append(boundary);
        sb1.append(linend);
        sb1.append("content-disposition: form-data; name=\"uploadfile\"; filename=\""
            + file.getvalue().getname() + "\"" + linend);
        sb1.append("content-type: application/octet-stream; charset=" + charset + linend);
        sb1.append(linend);
        outstream.write(sb1.tostring().getbytes());
        inputstream is = new fileinputstream(file.getvalue());
        byte[] buffer = new byte[1024];
        int len = 0;
        while ((len = is.read(buffer)) != -1) {
          outstream.write(buffer, 0, len);
        }
        is.close();
        outstream.write(linend.getbytes());
      }
    // 请求结束标志
    byte[] end_data = (prefix + boundary + prefix + linend).getbytes();
    outstream.write(end_data);
    outstream.flush();
    // 得到响应码
    int res = conn.getresponsecode();
    inputstream in = conn.getinputstream();
    stringbuilder sb2 = new stringbuilder();
    if (res == 200) {
      int ch;
      while ((ch = in.read()) != -1) {
        sb2.append((char) ch);
      }
    }
    outstream.close();
    conn.disconnect();
    return sb2.tostring();
  }
}

示例调用第二种方式上传：

final map<string, string> params = new hashmap<string, string>();
params.put("send_userid", string.valueof(id));
params.put("send_email", address);
params.put("send_name", name);
params.put("receive_email", emails);
final map<string, file> files = new hashmap<string, file>();
files.put("uploadfile", file);
final string request = uploadutil.post(requesturl, params, files);

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希望本文所述对大家android程序设计有所帮助。