mysql을 php에 뿌려준 것을 android에 가져오는 작업인데요
AsyncTask 하니 nullpointException 에러가 뜨는데ㅠ
어디서 값전달이 에러가 났는지 잘 모르겠네요ㅠㅠ
<NetworkTask.java>
package com.example.graph4;
import android.content.ContentValues;
import android.os.AsyncTask;
import android.widget.TextView;
class NetworkTask extends AsyncTask<Void, Void, String> {
private String url;
private ContentValues values;
TextView tv_outPut;
public NetworkTask(String url, ContentValues values) {
this.url = url;
this.values = values;
}
@Override
protected String doInBackground(Void... params) {
String result; // 요청 결과를 저장할 변수.
RequestHttpURLConnection requestHttpURLConnection = new RequestHttpURLConnection();
result = requestHttpURLConnection.request(url, values); // 해당 URL로 부터 결과물을 얻어온다.
return result;
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
//doInBackground()로 부터 리턴된 값이 onPostExecute()의 매개변수로 넘어오므로 s를 출력한다.
tv_outPut.setText(s);
}
}
|
<Logcat>
2019-10-10 16:53:26.508 8410-8410/com.example.graph4 E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.graph4, PID: 8410
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
at com.example.graph4.NetworkTask.onPostExecute(NetworkTask.java:35)
at com.example.graph4.NetworkTask.onPostExecute(NetworkTask.java:7)
at android.os.AsyncTask.finish(AsyncTask.java:695)
at android.os.AsyncTask.access$600(AsyncTask.java:180)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:712)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
