问题
On the click event add data to MySQL database through php on the localhost. Its showing following logcat error on the click event. Please help me to solve this problem.
08-11 07:31:06.416: D/gralloc_goldfish(971): Emulator without GPU emulation detected.
08-11 07:31:53.377: D/Inside Click(971): aaaaaaa
08-11 07:31:53.837: D/inid doinbackground(971): aaaaaaa
08-11 07:31:53.927: W/dalvikvm(971): threadid=11: thread exiting with uncaught exception (group=0x409961f8)
08-11 07:31:54.047: E/AndroidRuntime(971): FATAL EXCEPTION: AsyncTask #1
08-11 07:31:54.047: E/AndroidRuntime(971): java.lang.RuntimeException: An error occured while executing doInBackground()
08-11 07:31:54.047: E/AndroidRuntime(971): at android.os.AsyncTask$3.done(AsyncTask.java:278)
08-11 07:31:54.047: E/AndroidRuntime(971): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
08-11 07:31:54.047: E/AndroidRuntime(971): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
08-11 07:31:54.047: E/AndroidRuntime(971): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
08-11 07:31:54.047: E/AndroidRuntime(971): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
08-11 07:31:54.047: E/AndroidRuntime(971): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
08-11 07:31:54.047: E/AndroidRuntime(971): at java.lang.Thread.run(Thread.java:856)
08-11 07:31:54.047: E/AndroidRuntime(971): Caused by: java.lang.NullPointerException
08-11 07:31:54.047: E/AndroidRuntime(971): at com.example.connectiondemo.MainActivity$CreateBooking.doInBackground(MainActivity.java:1)
08-11 07:31:54.047: E/AndroidRuntime(971): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
08-11 07:31:54.047: E/AndroidRuntime(971): ... 5 more
08-11 07:31:58.986: I/Process(971): Sending signal. PID: 971 SIG: 9
My Activity
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
private static final String url="http://10.0.2.2/styletapphp/create_booking.php";
private static final String TAG_SUCCESS="Success";
JSONParser jsonParser;
JSONObject json;
TextView t1,t2,t3,t4,t5,t6,t7,t8,t9;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
t1=(TextView) findViewById(R.id.t1);
t2=(TextView) findViewById(R.id.t2);
t3=(TextView) findViewById(R.id.t3);
t4=(TextView) findViewById(R.id.t4);
t5=(TextView) findViewById(R.id.t5);
t6=(TextView) findViewById(R.id.t6);
t7=(TextView) findViewById(R.id.t7);
t8=(TextView) findViewById(R.id.t8);
//t9=(TextView) findViewById(R.id.t8);
t1.setText("Date");
t2.setText("Stylist");
t3.setText("9to10");
t4.setText("10to11");
t5.setText("11to12");
t6.setText("12to1");
t7.setText("2to3");
t8.setText("3to4");
Button butt1= (Button) findViewById(R.id.b1);
butt1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Log.d("Inside Click","aaaaaaa");
//new CreateBooking().execute();
new CreateBooking().execute("Date","Stylist", "9to10", "10to11", "11to12", "12to1","2to3", "3to4");
}
});
}
class CreateBooking extends AsyncTask<String,Integer,String>{
@Override
protected String doInBackground(String... params) {
Log.d("inid doinbackground","aaaaaaa");
List<NameValuePair> namevaluepair = new ArrayList<NameValuePair>();
namevaluepair.add(new BasicNameValuePair("bookingdate", params[0]));
namevaluepair.add(new BasicNameValuePair("stylist", params[1]));
namevaluepair.add(new BasicNameValuePair("status9to10", params[2]));
namevaluepair.add(new BasicNameValuePair("status10to11", params[3]));
namevaluepair.add(new BasicNameValuePair("status11to12", params[4]));
namevaluepair.add(new BasicNameValuePair("status12to1", params[5]));
namevaluepair.add(new BasicNameValuePair("status2to3", params[6]));
namevaluepair.add(new BasicNameValuePair("status3to4", params[7]));
/*List<NameValuePair>namevaluepair=new ArrayList<NameValuePair>();
namevaluepair.add(new BasicNameValuePair("bookingdate",t1.getText().toString()));
namevaluepair.add(new BasicNameValuePair("stylist",t2.getText().toString()));
namevaluepair.add(new BasicNameValuePair("status9to10",t3.getText().toString()));
namevaluepair.add(new BasicNameValuePair("status10to11",t4.getText().toString()));
namevaluepair.add(new BasicNameValuePair("status11to12",t5.getText().toString()));
namevaluepair.add(new BasicNameValuePair("status12to1",t6.getText().toString()));
namevaluepair.add(new BasicNameValuePair("status2to3",t7.getText().toString()));
namevaluepair.add(new BasicNameValuePair("status3to4",t8.getText().toString()));*/
json=jsonParser.makehttpRequest(url,"POST",namevaluepair);
Log.d("Create booking response",json.toString());
// check for success tag
try{int success=json.getInt(TAG_SUCCESS);
publishProgress(success);
}catch(JSONException e){
e.printStackTrace();
}
return null;
}
/*protected void onPostExecute(Integer integer) {
super.onPostExecute(integer);
if (integer == null)
return;
if (integer.intValue() == 1) {
Toast.makeText(getApplicationContext(), "booking successfull", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getApplicationContext(), "booking not successfull", Toast.LENGTH_LONG).show();
}
}
protected void onPostExecute(int i)
{
super.onPostExecute(i);
if (i==1){
// successfully created product
Toast.makeText(getApplicationContext(), "booking successfull", Toast.LENGTH_LONG).show();
}else{
// failed to create product
Toast.makeText(getApplicationContext(), "booking not successfull", Toast.LENGTH_LONG).show();
}
// if condition and toast message
} */
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
if (values[0] == null)
return;
if (values[0].intValue() == 1) {
Toast.makeText(getApplicationContext(), "booking successfull", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getApplicationContext(), "booking not successfull", Toast.LENGTH_LONG).show();
}
}
回答1:
jsonParser has never been initialized. You need to initialize before you can use it.
Also you can not make Network requests on the UIThread. This will cause a NetworkOnMainThreadException. You will need to use an AsyncTask. Check this NetworkOnMainThreadException
来源：https://stackoverflow.com/questions/25257736/an-error-occured-while-executing-doinbackground-fatal-exceptionasynctask-10