通过Java servlet从Android应用程序获取POST请求

Question

我正在开发一个项目，用Java servlet传递Android应用程序。在这个android应用程序中，在editText视图中输入的字符串应作为请求发送到Java servlet，Java servlet应将此字符串替换为另一个字符串作为响应。

以下是我的Android应用代码：

public class DoubleMeActivity extends Activity implements OnClickListener {

static EditText inputValue=null;
Integer doubledValue =0;
Button doubleMe;
TextView tv;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.calculate);

    inputValue = (EditText) findViewById(R.id.inputNum);
    doubleMe = (Button) findViewById(R.id.doubleme);
    tv = (TextView) findViewById(R.id.textView2);
    doubleMe.setOnClickListener(this);

 // check if you are connected or not
    if(isConnected()){
        tv.setBackgroundColor(0xFF00CC00);
        tv.setText("You are conncted");
    }
    else{
        tv.setText("You are NOT conncted");
    }

}



@Override
public void onClick(final View v) {

    switch (v.getId()){
    case R.id.doubleme:
        if(!validate())
            Toast.makeText(getBaseContext(), "Enter some data!", Toast.LENGTH_LONG).show();
        else

        new HttpAsyncTask().execute("http://139.179.92.123:8080/SmartStoreServlet/FemtoStore");






        break;
        }
}



private class HttpAsyncTask extends AsyncTask<String, Void, String> {
    @Override
    protected String doInBackground(String... urls) {



        return POST(urls[0]);
    }
    // onPostExecute displays the results of the AsyncTask.
    @Override
    protected void onPostExecute(String result) {
        Toast.makeText(getBaseContext(), "Data Sent!", Toast.LENGTH_LONG).show();
   }
}

public static String POST(String url){
    InputStream inputStream = null;
    String result = "";
    try {

        // 1. create HttpClient
        HttpClient httpclient = new DefaultHttpClient();

        // 2. make POST request to the given URL
        HttpPost httpPost = new HttpPost(url);

        JSONObject jsonObject = new JSONObject();
        jsonObject.accumulate("string" , inputValue.getText().toString());

        String json = jsonObject.toString();

        System.out.println(json);
        StringEntity se = new StringEntity(json);

        httpPost.setEntity(se);

        // 7. Set some headers to inform server about the type of the content   
        httpPost.setHeader("Accept", "application/json");
        httpPost.setHeader("Content-type", "application/json");

        // 8. Execute POST request to the given URL
        HttpResponse httpResponse = httpclient.execute(httpPost);
        System.out.println("ajsajsd" + inputStream); --> is not executed
        // 9. receive response as inputStream
        inputStream = httpResponse.getEntity().getContent();

        // 10. convert inputstream to string

        if(inputStream != null)
        {
            result = convertInputStreamToString(inputStream);
            System.out.println("jndkjsn" + result);
        }
        else
            result = "Did not work!";

    } catch (Exception e) {
        Log.d("InputStream", e.getLocalizedMessage());
    }

    // 11. return result
    return result;
}



private boolean validate(){
    if(inputValue.getText().toString().trim().equals("")) //DO CHECK
        return false;
    else
        return true;    
}

public boolean isConnected(){
    ConnectivityManager connMgr = (ConnectivityManager) getSystemService(Activity.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
        if (networkInfo != null && networkInfo.isConnected()) 
            return true;
        else
            return false;    
}

private static String convertInputStreamToString(InputStream inputStream) throws IOException{
    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
    String line = "";
    String result = "";
    while((line = bufferedReader.readLine()) != null)
        result += line;

    inputStream.close();
    return result;

}   

}

和我的java servlet代码：

public class FemtoStore extends HttpServlet {
private static final long serialVersionUID = 1L;

/**
 * @see HttpServlet#HttpServlet()
 */
public FemtoStore() {
    super();
    // TODO Auto-generated constructor stub
}

/**
 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
 */
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    doPost(request, response);
}

/**
 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
 */
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    System.out.println(request.getRemoteAddr());

    BufferedReader br = new BufferedReader(new InputStreamReader(request.getInputStream()));
    String json = "";
    if(br != null){
        json = br.readLine();
    }

    System.out.println(json);
}

}

问题是我在Android应用程序端获得连接拒绝错误，而我正在使用真实设备。如果你帮助我，我将非常感激。