Android 无法使用用户名和密码在HTTP Post请求上获取JSON数据？

使用get方法它是有效的，但当我尝试Post方法时，我什么也得不到。 请查看我的代码，并让我知道我做错了什么地方。
我有两个参数来传递用户名和密码

class AsyncT extends AsyncTask<Void, Void, Void> {
    @Override
    protected Void doInBackground(Void... voids) {


        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://192.168.1.105:8080/api/login");

        try {
            // Add your data
         List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
            nameValuePairs.add(new BasicNameValuePair("username", "adii@adii.com"));
            nameValuePairs.add(new BasicNameValuePair("password", "password"));
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            httppost.setHeader("content-type", "application/json; charset= utf-8");
            httppost.setHeader("Accept", "application/json");
            // Execute HTTP Post Request
            HttpResponse response = httpclient.execute(httppost);
            HttpEntity entity = response.getEntity();
            is = entity.getContent();


        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
        } catch (IOException e) {
            // TODO Auto-generated catch block
        }

        try {
            BufferedReader reader = null;
            if (is != null) {
                reader = new BufferedReader(new InputStreamReader(
                //"UTF-8"  "iso-8859-1"
                        is, "UTF-8"), 8);
            }
            StringBuilder sb = new StringBuilder();
            String line;
            if (reader != null) {
                while ((line = reader.readLine()) != null) {
                    sb.append(line).append("\n");


                }
            }
            if (is != null) {
                is.close();

            }
            result = sb.toString();

            Log.e("sb",result);

        } catch (Exception e) {
            Log.e("log_tag", "Error converting result " + e.toString());
        }
        return null;
    }

}

类AsyncT扩展了AsyncTask{
@凌驾
受保护的空位背景（空位…空位）{
HttpClient HttpClient=新的DefaultHttpClient（）；
HttpPost HttpPost=新的HttpPost（“http://192.168.1.105:8080/api/login");
试一试{
//添加您的数据
List nameValuePairs=新的ArrayList（2）；
添加（新的BasicNameValuePair（“用户名”adii@adii.com"));
添加（新的BasicNameValuePair（“密码”、“密码”））；
setEntity（新的UrlEncodedFormEntity（nameValuePairs））；
setHeader（“内容类型”，“应用程序/json；字符集=utf-8”）；
setHeader（“接受”、“应用程序/json”）；
//执行HTTP Post请求
HttpResponse response=httpclient.execute（httppost）；
HttpEntity=response.getEntity（）；
is=entity.getContent（）；
}捕获（客户端协议例外e）{
//TODO自动生成的捕捉块
}捕获（IOE异常）{
//TODO自动生成的捕捉块
}
试一试{
BufferedReader reader=null；
如果（is！=null）{
reader=新的BufferedReader（新的InputStreamReader(
//“UTF-8”“iso-8859-1”
为“UTF-8”）、8）；
}
StringBuilder sb=新的StringBuilder（）；
弦线；
if（读卡器！=null）{
而（（line=reader.readLine（））！=null）{
sb.append（行）。append（“\n”）；
}
}
如果（is！=null）{
is.close（）；
}
结果=sb.toString（）；
Log.e（“sb”，结果）；
}捕获（例外e）{
Log.e（“Log_标记”，“错误转换结果”+e.toString（））；
}
返回null；
}
}

我不知道你的代码有什么问题，但你应该试试这段代码，它在这里对我非常有效。希望对你有帮助

class AsyncT extends AsyncTask<Void, Void, Void> {
    @Override
    protected Void doInBackground(Void... voids) {


        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://192.168.1.105:8080/api/login");

        try {
            // Add your data
         List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
            nameValuePairs.add(new BasicNameValuePair("username", "adii@adii.com"));
            nameValuePairs.add(new BasicNameValuePair("password", "password"));
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            httppost.setHeader("content-type", "application/json; charset= utf-8");
            httppost.setHeader("Accept", "application/json");
            // Execute HTTP Post Request
            HttpResponse response = httpclient.execute(httppost);
            HttpEntity entity = response.getEntity();
            is = entity.getContent();


        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
        } catch (IOException e) {
            // TODO Auto-generated catch block
        }

        try {
            BufferedReader reader = null;
            if (is != null) {
                reader = new BufferedReader(new InputStreamReader(
                //"UTF-8"  "iso-8859-1"
                        is, "UTF-8"), 8);
            }
            StringBuilder sb = new StringBuilder();
            String line;
            if (reader != null) {
                while ((line = reader.readLine()) != null) {
                    sb.append(line).append("\n");


                }
            }
            if (is != null) {
                is.close();

            }
            result = sb.toString();

            Log.e("sb",result);

        } catch (Exception e) {
            Log.e("log_tag", "Error converting result " + e.toString());
        }
        return null;
    }

}

public String ip = "192.168.43.114";
public String port = "59397";

public HttpPost httppost;
String ServerAddress;
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();

JSONObject json = new JSONObject();

公共字符串ip=“192.168.43.114”； 公共字符串端口=“59397”； 公共HttpPost-HttpPost； 字符串服务器地址； ArrayList nameValuePairs=新的ArrayList（）； JSONObject json=新的JSONObject（）； 尝试在函数中实现任务，使其可重用

class AsyncT extends AsyncTask<Void, Void, Void> {
    @Override
    protected Void doInBackground(Void... voids) {


        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://192.168.1.105:8080/api/login");

        try {
            // Add your data
         List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
            nameValuePairs.add(new BasicNameValuePair("username", "adii@adii.com"));
            nameValuePairs.add(new BasicNameValuePair("password", "password"));
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            httppost.setHeader("content-type", "application/json; charset= utf-8");
            httppost.setHeader("Accept", "application/json");
            // Execute HTTP Post Request
            HttpResponse response = httpclient.execute(httppost);
            HttpEntity entity = response.getEntity();
            is = entity.getContent();


        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
        } catch (IOException e) {
            // TODO Auto-generated catch block
        }

        try {
            BufferedReader reader = null;
            if (is != null) {
                reader = new BufferedReader(new InputStreamReader(
                //"UTF-8"  "iso-8859-1"
                        is, "UTF-8"), 8);
            }
            StringBuilder sb = new StringBuilder();
            String line;
            if (reader != null) {
                while ((line = reader.readLine()) != null) {
                    sb.append(line).append("\n");


                }
            }
            if (is != null) {
                is.close();

            }
            result = sb.toString();

            Log.e("sb",result);

        } catch (Exception e) {
            Log.e("log_tag", "Error converting result " + e.toString());
        }
        return null;
    }

}

public int login(String username, String password)  {
        ServerAddress = "http://"+ip+":"+port+"/api/Users/Login";
        Log.v("check","inLoginMethod");
        try {

            json = new JSONObject();
            json.put("UserName", username);
            json.put("PassWord", password);

            AsyncTask<String, Integer, String> asynchTask;
            AsynchServerConnection asc = new AsynchServerConnection();
            asynchTask = asc.execute("");
            String res = asynchTask.get();
            Log.v("RES", res);

            //res = jsonObject.toString();
            //int check = Integer.parseInt(res);
            Log.i("checkR", res + "here");
            return res;

        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            Log.i("checkR", "Interrupted exception");
            return 0;
        } catch (ExecutionException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            Log.i("checkR", "ExecutionException");
            return 0;
        } 
        catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            Log.i("checkR", "JSONException");
            Log.i("checkR", e.getMessage());
            return 0;
        }
}

public int登录（字符串用户名、字符串密码）{
ServerAddress=“http://“+ip+”：“+port+”/api/Users/Login”；
Log.v（“检查”、“输入法”）；
试一试{
json=新的JSONObject（）；
put（“用户名”，UserName）；
put（“密码”，PassWord）；
异步任务异步任务；
AsynchServerConnection asc=新的AsynchServerConnection（）；
asynchTask=asc.execute（“”）；
String res=asynchTask.get（）；
Log.v（“RES”，RES）；
//res=jsonObject.toString（）；
//int check=Integer.parseInt（res）；
Log.i（“checkR”，res+“此处”）；
返回res；
}捕捉（中断异常e）{
//TODO自动生成的捕捉块
e、 printStackTrace（）；
Log.i（“检查”、“中断异常”）；
返回0；
}捕获（执行例外）{
//TODO自动生成的捕捉块
e、 printStackTrace（）；
Log.i（“检查”、“执行例外”）；
返回0；
} 
捕获（JSONException e）{
//TODO自动生成的捕捉块
e、 printStackTrace（）；
Log.i（“checkR”、“JSONException”）；
Log.i（“checkR”，即getMessage（））；
返回0；
}
}

最后是异步任务类

class AsyncT extends AsyncTask<Void, Void, Void> {
    @Override
    protected Void doInBackground(Void... voids) {


        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://192.168.1.105:8080/api/login");

        try {
            // Add your data
         List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
            nameValuePairs.add(new BasicNameValuePair("username", "adii@adii.com"));
            nameValuePairs.add(new BasicNameValuePair("password", "password"));
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            httppost.setHeader("content-type", "application/json; charset= utf-8");
            httppost.setHeader("Accept", "application/json");
            // Execute HTTP Post Request
            HttpResponse response = httpclient.execute(httppost);
            HttpEntity entity = response.getEntity();
            is = entity.getContent();


        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
        } catch (IOException e) {
            // TODO Auto-generated catch block
        }

        try {
            BufferedReader reader = null;
            if (is != null) {
                reader = new BufferedReader(new InputStreamReader(
                //"UTF-8"  "iso-8859-1"
                        is, "UTF-8"), 8);
            }
            StringBuilder sb = new StringBuilder();
            String line;
            if (reader != null) {
                while ((line = reader.readLine()) != null) {
                    sb.append(line).append("\n");


                }
            }
            if (is != null) {
                is.close();

            }
            result = sb.toString();

            Log.e("sb",result);

        } catch (Exception e) {
            Log.e("log_tag", "Error converting result " + e.toString());
        }
        return null;
    }

}

private class AsynchServerConnection extends
            AsyncTask<String, Integer, String> {

        @Override
        protected void onPostExecute(String result) {
            // TODO Auto-generated method stub

            super.onPostExecute(result);
        }

        @Override
        protected void onProgressUpdate(Integer... values) {
            // TODO Auto-generated method stub

            super.onProgressUpdate(values);
        }

        @Override
        protected String doInBackground(String... params) {
            // TODO Auto-generated method stub

            String result = null;
            try {
                 HttpClient client = new DefaultHttpClient();

                    HttpConnectionParams.setConnectionTimeout(client.getParams(), 3000); //Timeout Limit
                    HttpResponse response;


                    try {
                         HttpPost post = new HttpPost(ServerAddress);
                         Log.v(TAG, "server Addr: "+ServerAddress);

                        StringEntity se = new StringEntity( json.toString());
                        se.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));

                        post.setEntity(se);
                        response = client.execute(post);

                        /*Checking response */
                        if(response!=null){

                            HttpEntity e = response.getEntity();
                            String r =EntityUtils.toString(e);
                            result = r;
                            Log.v("checkR", r);
                        }

                    } catch(Exception e) {
                        e.printStackTrace();
                        Log.v("check", "exception");
                        Log.v("check", e.getMessage());
                        //createDialog("Error", "Cannot Estabilish Connection");
                    }

                return result;

            } catch (Exception e) {
                // TODO Auto-generated catch block

                e.printStackTrace();
            }
            return result;
        }
    }

私有类AsynchServerConnection扩展
异步任务{
@凌驾
受保护的void onPostExecute（字符串结果）{
//TODO自动生成的方法存根
super.onPostExecute（结果）；
}
@凌驾
受保护的void onProgressUpdate（整型…值）{
//TODO自动生成的方法存根
super.onProgressUpdate（值）；
}
@凌驾
受保护的字符串doInBackground（字符串…参数）{
//TODO自动生成的方法存根
字符串结果=null；
试一试{
HttpClient=new DefaultHttpClient（）；
HttpConnectionParams.setConnectionTimeout（client.getParams（），3000）；//超时限制
HttpResponse响应；
试一试{
HttpPost=新的HttpPost（服务器地址）；
Log.v（标签“服务器地址：”+ServerAddress）；
StringEntity se=新的StringEntity（json.toString（））；
setContentType（新的BasicHeader（HTTP.CONTENT_TYPE，“application/json”）；
邮政实体（se）；
响应=client.execute（post）；
/*检查响应*/
if（响应！=null）{
HttpEntity e=response.getEntity（）；
字符串r=EntityUtils.toString（e）；
结果=r；
Log.v（“checkR”，r）；
}
}捕获（例外e）{
e、 printStackTrace（）；
Log.v（“检查”、“例外”）；
Log.v（“check”，e.getMessage（））；
//createDialog（“错误”，“无法建立连接”）；
}
返回结果；
}捕获（例外e）{
//TODO自动生成的捕捉块