我正在尝试以表格形式将我的数据从mysql数据库获取到android应用程序 公共类MainActivity扩展活动{ 表格布局tl； 创建时的公共void（Bundle savedInstanceState） { super.onCreate（savedInstanceState）； setContentView（R.layout.activity_main）； tl=（TableLayout）findviewbyd（R.id.table）； 类DownloadTask扩展了AsyncTask { 字符串结果=null； InputStream=null； @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 试一试{ HttpClient HttpClient=新的DefaultHttpClient（）； HttpPost HttpPost=新的HttpPost（“http://192.168.1.3/worker2.php"); HttpResponse response=httpclient.execute（httppost）； HttpEntity=response.getEntity（）； is=entity.getContent（）； Log.e（“Log_标签”，“连接成功”）； }捕获（例外e）{ e（“Log_标记”，“http连接错误”+e.toString（））； } 返回null； } @凌驾 受保护的void onPostExecute（字符串结果）{ //TODO自动生成的方法存根 试一试{ JSONArray jArray=新JSONArray（结果）； TableLayout tv=（TableLayout）findViewById（R.id.table）； tv.removeAllViewsInLayout（）； int标志=1； for（int i=-1；i

错误

10-13 15:21:20.743:E/log_标记（3135）：http connectionorg.apache.http.conn.HttpHostConnectException:连接到http://localhost:3307 拒绝
10-13 15:21:20.763:E/AndroidRuntime（3135）：致命异常：main
10-13 15:21:20.763:E/AndroidRuntime（3135）：进程：com.example.inform，PID:3135
10-13 15:21:20.763:E/AndroidRuntime（3135）：java.lang.NullPointerException
10-13 15:21:20.763:E/AndroidRuntime（3135）：位于org.json.JSONTokener.nextCleanInternal（JSONTokener.java:116）
10-13 15:21:20.763:E/AndroidRuntime（3135）：位于org.json.JSONTokener.nextValue（JSONTokener.java:94）
10-13 15:21:20.763:E/AndroidRuntime（3135）：位于org.json.JSONArray（JSONArray.java:92）
10-13 15:21:20.763:E/AndroidRuntime（3135）：位于org.json.JSONArray（JSONArray.java:108）
10-13 15:21:20.763:E/AndroidRuntime（3135）：在com.example.inform.MainActivity$1DownloadTask.onPostExecute（MainActivity.java:69）
10-13 15:21:20.763:E/AndroidRuntime（3135）：在com.example.inform.MainActivity$1DownloadTask.onPostExecute（MainActivity.java:1）
10-13 15:21:20.763:E/AndroidRuntime（3135）：在android.os.AsyncTask.finish（AsyncTask.java:632）
10-13 15:21:20.763:E/AndroidRuntime（3135）：在android.os.AsyncTask.access$600（AsyncTask.java:177）
10-13 15:21:20.763:E/AndroidRu
public class MainActivity extends Activity {
TableLayout tl;

public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);     
    setContentView(R.layout.activity_main);

    tl= (TableLayout) findViewById(R.id.table);

    class DownloadTask extends AsyncTask<String, Void, String>
    {       
        String result = null;
        InputStream is = null;
        @Override
        protected String doInBackground(String... params) {
            // TODO Auto-generated method stub
            try {
    HttpClient httpclient = new DefaultHttpClient();                    
    HttpPost httppost = new HttpPost("http://192.168.1.3/worker2.php");                 
    HttpResponse response = httpclient.execute(httppost);                   
    HttpEntity entity = response.getEntity();

    is = entity.getContent();                   

                Log.e("log_tag", "connection success");                 

                } catch (Exception e) {
        Log.e("log_tag", "Error in http connection" + e.toString());                    
                }
            return null;
        }
        @Override
        protected void onPostExecute(String result) {
            // TODO Auto-generated method stub
            try {
            JSONArray jArray = new JSONArray(result);
            TableLayout tv = (TableLayout) findViewById(R.id.table);
            tv.removeAllViewsInLayout();
            int flag = 1;
            for (int i = -1; i < jArray.length() - 1; i++) {
            TableRow tr = new TableRow(MainActivity.this);
            tr.setLayoutParams(new LayoutParams(
            LayoutParams.FILL_PARENT,
            LayoutParams.WRAP_CONTENT));
            if (flag == 1) {
            TextView b6 = new TextView(MainActivity.this);

            b6.setText("Id");                           
            b6.setTextColor(Color.BLUE);

            b6.setTextSize(15);                         
            tr.addView(b6);

            TextView b19 = new TextView(MainActivity.this);

            b19.setPadding(10, 0, 0, 0);                            
            b19.setTextSize(15);

            b19.setText("Name");                            
            b19.setTextColor(Color.BLUE);
            tr.addView(b19);
            TextView b29 = new TextView(MainActivity.this);
            b29.setPadding(10, 0, 0, 0);
            b29.setText("Status");
            b29.setTextColor(Color.BLUE);
            b29.setTextSize(15);
            tr.addView(b29);

            tv.addView(tr);                         
            final View vline = new View(MainActivity.this);

            vline.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.FILL_PARENT, 2));
            vline.setBackgroundColor(Color.BLUE);

            tv.addView(vline);
            flag = 0;                           
            } 
                    else 
            {   
            JSONObject json_data = jArray.getJSONObject(i);
            Log.i("log_tag", "id: " + json_data.getInt("Worker_id") + ", Username: " + json_data.getString("Worker_name") + ", No: " + json_data.getString("Nationality"));
            TextView b = new TextView(MainActivity.this);
            String stime = String.valueOf(json_data.getInt("Worker_id"));
            b.setText(stime);
            b.setTextColor(Color.RED);
            b.setTextSize(15);
            tr.addView(b);
            TextView b1 = new TextView(MainActivity.this);
            b1.setPadding(10, 0, 0, 0);
            b1.setTextSize(15);
            String stime1 = json_data.getString("Worker_name");
            b1.setText(stime1);
            b1.setTextColor(Color.BLACK);
            tr.addView(b1);
            TextView b2 = new TextView(MainActivity.this);
            b2.setPadding(10, 0, 0, 0);
            String stime2 = json_data.getString("Nationality");
            b2.setText(stime2);
            b2.setTextColor(Color.BLACK);
            b2.setTextSize(15);
            tr.addView(b2);
            tv.addView(tr);
            final View vline1 = new View(MainActivity.this);
            vline1.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.FILL_PARENT, 1));
            vline1.setBackgroundColor(Color.WHITE);
            tv.addView(vline1);
                    }
                }
            } catch (JSONException e) {
                Log.e("log_tag", "Error parsing data" + e.toString());
                Toast.makeText(getApplicationContext(), "JsonArray fail", Toast.LENGTH_SHORT).show();
            }

            super.onPostExecute(result);
        }
    }
 DownloadTask dl = new DownloadTask();
dl.execute();
}

10-13 15:21:20.743: E/log_tag(3135): Error in http connectionorg.apache.http.conn.HttpHostConnectException: Connection to http://localhost:3307 refused
10-13 15:21:20.763: E/AndroidRuntime(3135): FATAL EXCEPTION: main
10-13 15:21:20.763: E/AndroidRuntime(3135): Process: com.example.inform, PID: 3135
10-13 15:21:20.763: E/AndroidRuntime(3135): java.lang.NullPointerException
10-13 15:21:20.763: E/AndroidRuntime(3135):     at org.json.JSONTokener.nextCleanInternal(JSONTokener.java:116)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at org.json.JSONTokener.nextValue(JSONTokener.java:94)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at org.json.JSONArray.<init>(JSONArray.java:92)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at org.json.JSONArray.<init>(JSONArray.java:108)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at com.example.inform.MainActivity$1DownloadTask.onPostExecute(MainActivity.java:69)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at com.example.inform.MainActivity$1DownloadTask.onPostExecute(MainActivity.java:1)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at android.os.AsyncTask.finish(AsyncTask.java:632)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at android.os.AsyncTask.access$600(AsyncTask.java:177)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at android.os.Handler.dispatchMessage(Handler.java:102)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at android.os.Looper.loop(Looper.java:136)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at android.app.ActivityThread.main(ActivityThread.java:5001)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at java.lang.reflect.Method.invokeNative(Native Method)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at java.lang.reflect.Method.invoke(Method.java:515)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
10-13 15:21:20.763: E/AndroidRuntime(3135):     at dalvik.system.NativeStart.main(Native Method)