java - 地理编码器 getfromlocationName 使应用程序崩溃

Question

我正在尝试创建一个简单的函数，可以在其中从邮政编码中查找信息。在下面提供的代码中，如果我输入有效的邮政编码，它就可以正常工作。但是当我输入错误的邮政编码时问题就开始了。我尝试使用语句 try catch 但没有显示错误，整个应用程序崩溃了。我还想知道如何限制仅在英国进行搜索。通过邮政编码查找地址是否有比使用 getfromlocationName 函数更好的选择。

public void finder(String query){
      Geocoder geocoder;
      List<Address> addresses = new ArrayList<Address>();
      geocoder = new Geocoder(this, Locale.getDefault());

      try {
          //addresses = geocoder.getFromLocation(51.283973, 1.064928, 1); // Here 1 represent max location result to returned, by documents it recommended 1 to 5
          addresses = geocoder.getFromLocationName(query,1);
      } catch (Exception e) {

          Toast.makeText(MainActivity.this, "Fail " + e.getMessage(), Toast.LENGTH_SHORT).show();
      }

      String street = addresses.get(0).getThoroughfare();
      Log.i("I0",street);


      String city = addresses.get(0).getLocality();
      Log.i("I1",city);

      String county = addresses.get(0).getSubAdminArea();
      Log.i("I2",county);

      String country = addresses.get(0).getCountryName();
      Log.i("I3",country);
      String postalCode = addresses.get(0).getPostalCode();
      Log.i("I4",postalCode);

      display.setText(street + "\n" + city + "\n" + country + "\n" + postalCode  ); }

错误是

07-13 21:15:26.717 10744-10744/com.example.mandeep.testing I/i1: ct3456
07-13 21:15:26.856 10744-10744/com.example.mandeep.testing D/AndroidRuntime: Shutting down VM
07-13 21:15:26.857 10744-10744/com.example.mandeep.testing E/AndroidRuntime: FATAL EXCEPTION: main
                                                                             Process: com.example.mandeep.testing, PID: 10744
                                                                             java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
                                                                                 at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
                                                                                 at java.util.ArrayList.get(ArrayList.java:308)
                                                                                 at com.example.mandeep.testing.MainActivity.finder(MainActivity.java:85)
                                                                                 at com.example.mandeep.testing.MainActivity$1.onQueryTextSubmit(MainActivity.java:47)
                                                                                 at android.widget.SearchView.onSubmitQuery(SearchView.java:1197)
                                                                                 at android.widget.SearchView.access$900(SearchView.java:92)
                                                                                 at android.widget.SearchView$8.onEditorAction(SearchView.java:1175)
                                                                                 at android.widget.TextView.onEditorAction(TextView.java:4473)
                                                                                 at com.android.internal.widget.EditableInputConnection.performEditorAction(EditableInputConnection.java:139)
                                                                                 at com.android.internal.view.IInputConnectionWrapper.executeMessage(IInputConnectionWrapper.java:304)
                                                                                 at com.android.internal.view.IInputConnectionWrapper$MyHandler.handleMessage(IInputConnectionWrapper.java:78)
                                                                                 at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                                 at android.os.Looper.loop(Looper.java:135)
                                                                                 at android.app.ActivityThread.main(ActivityThread.java:5219)
                                                                                 at java.lang.reflect.Method.invoke(Native Method)
                                                                                 at java.lang.reflect.Method.invoke(Method.java:372)
                                                                                 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:898)
                                                                                 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:693)
07-13 21:15:26.878 10744-10744/? I/Process: Sending signal. PID: 10744 SIG: 9

我试过了

if(addresses != null && addresses.size() > 0) {

          String street = addresses.get(0).getThoroughfare();
          Log.i("I0", street);


          String city = addresses.get(0).getLocality();
          Log.i("I1", city);

          String county = addresses.get(0).getSubAdminArea();
          Log.i("I2", county);

          String country = addresses.get(0).getCountryName();
          Log.i("I3", country);
          String postalCode = addresses.get(0).getPostalCode();
          Log.i("I4", postalCode);

          display.setText(street + "\n" + city + "\n" + country + "\n" + postalCode);
      }
      else{
          Toast.makeText(MainActivity.this, "No Results Found", Toast.LENGTH_SHORT).show();
      }

还是同样的问题。

我现在已经编辑了代码

public void finder(String query){
      Geocoder geocoder;
      List<Address> addresses = new ArrayList<Address>();
      geocoder = new Geocoder(this, Locale.getDefault());

      try {
          //addresses = geocoder.getFromLocation(51.283973, 1.064928, 1); // Here 1 represent max location result to returned, by documents it recommended 1 to 5
          addresses = geocoder.getFromLocationName(query,1);
      } catch (Exception e) {

          Toast.makeText(MainActivity.this, "Fail " + e.getMessage(), Toast.LENGTH_SHORT).show();
      }

      Log.i("yes",addresses.size() + "");

      if(addresses != null && addresses.size() > 0) {
          Log.i("yes","checked");

          String street = addresses.get(0).getThoroughfare();
          Log.i("I0", street);


          String city = addresses.get(0).getLocality();
          Log.i("I1", city);

          String county = addresses.get(0).getSubAdminArea();
          Log.i("I2", county);

          String country = addresses.get(0).getCountryName();
          Log.i("I3", country);
          String postalCode = addresses.get(0).getPostalCode();
          Log.i("I4", postalCode);

          display.setText(street + "\n" + city + "\n" + country + "\n" + postalCode);
      }
      else{
          Toast.makeText(MainActivity.this, "No Results Found", Toast.LENGTH_SHORT).show();
      }


  }

现在错误是

07-13 22:21:02.782 32088-32088/com.example.mandeep.testing I/i1: ct28dx
07-13 22:21:02.942 32088-32088/com.example.mandeep.testing I/yes: 1
07-13 22:21:02.942 32088-32088/com.example.mandeep.testing I/yes: checked
07-13 22:21:02.942 32088-32088/com.example.mandeep.testing D/AndroidRuntime: Shutting down VM
07-13 22:21:02.944 32088-32088/com.example.mandeep.testing E/AndroidRuntime: FATAL EXCEPTION: main
                                                                             Process: com.example.mandeep.testing, PID: 32088
                                                                             java.lang.NullPointerException: println needs a message
                                                                                 at android.util.Log.println_native(Native Method)
                                                                                 at android.util.Log.i(Log.java:160)
                                                                                 at com.example.mandeep.testing.MainActivity.finder(MainActivity.java:93)
                                                                                 at com.example.mandeep.testing.MainActivity$1.onQueryTextSubmit(MainActivity.java:52)
                                                                                 at android.widget.SearchView.onSubmitQuery(SearchView.java:1197)
                                                                                 at android.widget.SearchView.access$900(SearchView.java:92)
                                                                                 at android.widget.SearchView$8.onEditorAction(SearchView.java:1175)
                                                                                 at android.widget.TextView.onEditorAction(TextView.java:4473)
                                                                                 at com.android.internal.widget.EditableInputConnection.performEditorAction(EditableInputConnection.java:139)
                                                                                 at com.android.internal.view.IInputConnectionWrapper.executeMessage(IInputConnectionWrapper.java:304)
                                                                                 at com.android.internal.view.IInputConnectionWrapper$MyHandler.handleMessage(IInputConnectionWrapper.java:78)
                                                                                 at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                                 at android.os.Looper.loop(Looper.java:135)
                                                                                 at android.app.ActivityThread.main(ActivityThread.java:5219)
                                                                                 at java.lang.reflect.Method.invoke(Native Method)
                                                                                 at java.lang.reflect.Method.invoke(Method.java:372)
                                                                                 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:898)
                                                                                 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:693)
07-13 22:21:02.973 32088-32088/com.example.mandeep.testing I/Process: Sending signal. PID: 32088 SIG: 9

Answer 1

您应该首先检查数组的大小

if(addresses.size() > 0){
    String street = addresses.get(0).getThoroughfare();
          Log.i("I0",street);


          String city = addresses.get(0).getLocality();
          Log.i("I1",city);

          String county = addresses.get(0).getSubAdminArea();
          Log.i("I2",county);

          String country = addresses.get(0).getCountryName();
          Log.i("I3",country);
          String postalCode = addresses.get(0).getPostalCode();
          Log.i("I4",postalCode);

          display.setText(street + "\n" + city + "\n" + country + "\n" + postalCode  ); 
}

您尝试从索引 0 获取数据，但列表为空。