android手机端上传指定路径的文件

手机端代码：

public class MainActivity extends Activity {

     @Override

     protected void onCreate(Bundle savedInstanceState) {

           super.onCreate(savedInstanceState);

          setContentView(R.layout. activity_main);

     }

     public void onclick(View view){

          String uploadUrl = "http://192.168.0.103:8080/upload/UploadServlet" ;//ip根据机器ip设置

          String end = "\r\n";

          String twoHyphens = "--";//两个连字符

          String boundary = "******";//分界符

          String filename = Environment.getExternalStorageDirectory()+ "/my.jpg";//上传文件的路径

           try {

              URL url = new URL(uploadUrl);

              HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();

              httpURLConnection.setDoInput( true);

              httpURLConnection.setDoOutput( true);

              httpURLConnection.setUseCaches( false);

              httpURLConnection.setRequestMethod( "POST");//必须大写

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

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

               httpURLConnection.setRequestProperty( "Content-type", "multipart/form-data;boundary=" +boundary);

              DataOutputStream dos = new DataOutputStream(httpURLConnection.getOutputStream());

              dos.writeBytes(twoHyphens+boundary+end);

               dos.writeBytes( "Content-Disposition:form-data; name=\"file\"; filename=\""

                        +filename.substring(filename.lastIndexOf( "/")+1)+"\"" +end);

              dos.writeBytes(end);

               if(!new File(filename).exists()){

                   Toast. makeText(this, "文件不存在" , 1000).show();

                    return;

              }

              FileInputStream fis = new FileInputStream(filename);

               byte[] buf = new byte[8192];

               int count = 0;

               while((count = fis.read(buf))>0){

                   dos.write(buf, 0, count);

              }

              fis.close();

              dos.writeBytes(end);

               dos.writeBytes(twoHyphens+boundary+twoHyphens+end);

              dos.flush();

              InputStream is = httpURLConnection.getInputStream();

              InputStreamReader isr = new InputStreamReader(is,"utf-8" );

              BufferedReader br = new BufferedReader(isr);

              String result = br.readLine();

              Toast. makeText(this, result, Toast.LENGTH_LONG).show();

              dos.close();

              is.close();             

          } catch (Exception e) {

              e.printStackTrace();

          }

     }

}