我正在创建这个Android应用程序，它获取一些数据，然后在特定间隔后显示通知。但每当我运行它，它就会关闭。这是我正在使用的代码。它从之前的活动中获取了一些数据。
package com.example.boschcarservice;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.HashMap;
import java.util.List;
import java.util.Random;
import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.AlarmManager;
import android.app.ListActivity;
import android.app.PendingIntent;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.app.ProgressDialog;
import android.telephony.SmsManager;
import android.util.Log;
import android.view.Menu;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
private ProgressDialog pDialog;
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> productsList;
private static String url_all_products = "http://bosch-car-mohali.com/home/boschcar/android_connect/get_product_details.php";
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "products";
private String TAG_PID = null;
JSONArray products = null;
TextView t1,t2,t3;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
t1= (TextView) findViewById(R.id.textView4);
t2= (TextView) findViewById(R.id.textView5);
t3= (TextView) findViewById(R.id.textView7);
Bundle extras = getIntent().getExtras();
TAG_PID=extras.getString("pid");
productsList = new ArrayList<HashMap<String, String>>();
// Loading products in Background Thread
new LoadAllProducts().execute();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar calendar = Calendar.getInstance();
String dt= t3.getText().toString();
try {
calendar.setTime(sdf.parse(dt));
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Intent myIntent = new Intent(this, MyReciever.class);
PendingIntent pi= PendingIntent.getBroadcast(this, 0, myIntent,0);
AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),10*24*60*60*1000, pi);
}
class LoadAllProducts extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Loading products. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All products from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray(TAG_PRODUCTS);
// looping through All Products
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
String pid = c.getString(TAG_PID);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_PID, pid);
// adding HashList to ArrayList
productsList.add(map);
}
} else {
Toast.makeText(getApplicationContext(), "Connection Error",Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
t1.setText(productsList.get(1).toString());
t2.setText(productsList.get(3).toString());
String dt = t1.getText().toString(); // Start date
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar c = Calendar.getInstance();
try {
c.setTime(sdf.parse(dt));
} catch (ParseException e) {
e.printStackTrace();
}
c.add(Calendar.DATE, 15); // number of days to add, can also use Calendar.DAY_OF_MONTH in place of Calendar.DATE
SimpleDateFormat sdf1 = new SimpleDateFormat("yyyy-MM-dd");
t3.setText(sdf1.format(c.getTime()).toString());
}
});
}
}
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
编辑： 这是日志
12-06 16:30:57.947: E/AndroidRuntime(827): FATAL EXCEPTION: main
12-06 16:30:57.947: E/AndroidRuntime(827): android.os.NetworkOnMainThreadException
12-06 16:30:57.947: E/AndroidRuntime(827): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
12-06 16:30:57.947: E/AndroidRuntime(827): at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
12-06 16:30:57.947: E/AndroidRuntime(827): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
12-06 16:30:57.947: E/AndroidRuntime(827): at java.net.InetAddress.getAllByName(InetAddress.java:214)
12-06 16:30:57.947: E/AndroidRuntime(827): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
12-06 16:30:57.947: E/AndroidRuntime(827): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
12-06 16:30:57.947: E/AndroidRuntime(827): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
12-06 16:30:57.947: E/AndroidRuntime(827): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
12-06 16:30:57.947: E/AndroidRuntime(827): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
12-06 16:30:57.947: E/AndroidRuntime(827): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
12-06 16:30:57.947: E/AndroidRuntime(827): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
12-06 16:30:57.947: E/AndroidRuntime(827): at com.example.boschcarservice.JSONParser.makeHttpRequest(JSONParser.java:61)
12-06 16:30:57.947: E/AndroidRuntime(827): at com.example.boschcarservice.gpass$1.run(gpass.java:78)
12-06 16:30:57.947: E/AndroidRuntime(827): at android.os.Handler.handleCallback(Handler.java:725)
12-06 16:30:57.947: E/AndroidRuntime(827): at android.os.Handler.dispatchMessage(Handler.java:92)
12-06 16:30:57.947: E/AndroidRuntime(827): at android.os.Looper.loop(Looper.java:137)
12-06 16:30:57.947: E/AndroidRuntime(827): at android.app.ActivityThread.main(ActivityThread.java:5039)
12-06 16:30:57.947: E/AndroidRuntime(827): at java.lang.reflect.Method.invokeNative(Native Method)
12-06 16:30:57.947: E/AndroidRuntime(827): at java.lang.reflect.Method.invoke(Method.java:511)
12-06 16:30:57.947: E/AndroidRuntime(827): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
12-06 16:30:57.947: E/AndroidRuntime(827): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
12-06 16:30:57.947: E/AndroidRuntime(827): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：0)
答案 1 :(得分：0)
错误意味着您正在尝试在主线程或UI线程中执行一些与网络相关的操作。
尝试这样做的问题是，如果网络需要很长时间才能响应，那么UI将被冻结，因此用户体验会很糟糕。
为了避免这种情况，Android希望您在UI线程之外执行任何与UI无关的操作。在这种情况下，你应该创建一个像另一个答案中建议的AsyncTask，然后将所有与网络相关的代码放在那里。
然后你可以在UI线程中启动这个AsynTask，如果网络超时或响应缓慢，UI将继续工作。
基本上，AsyncTask将创建一个通过doInBackground（）方法执行代码的新线程。然后是as per the documentation：
onPostExecute（Result），在后台后的UI线程上调用 计算结束。背景计算的结果是 作为参数传递给此步骤
因此，您可以从AyncTask获取信息，然后在UI中执行某些操作。