Expected Android Studio "class" or "interface"

Question

I follow the instructions at http://developer.android.com/training/location/retrieve-current.html to display the location of the user. But leading to the above compilation error.

this is my code

public class MainActivity extends ActionBarActivity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener { private GoogleApiClient mGoogleApiClient; private Location mLastLocation; TextView tv1 = (TextView) findViewById(R.id.lat); TextView tv2 = (TextView) findViewById(R.id.lon); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //ERROR '}' expected protected synchronized void buildGoogleApiClient() { mGoogleApiClient = new GoogleApiClient.Builder(this) .addConnectionCallbacks(this) .addOnConnectionFailedListener(this) .addApi(LocationServices.API) .build(); } } // ERROR 'class' or 'interface' expected @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); //noinspection SimplifiableIfStatement if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } @Override public void onConnected(Bundle connectionHint) { mLastLocation = LocationServices.FusedLocationApi.getLastLocation( mGoogleApiClient); if (mLastLocation != null) { tv1.setText(String.valueOf(mLastLocation.getLatitude())); tv1.setText(String.valueOf(mLastLocation.getLongitude())); } } @Override public void onConnectionSuspended(int i) { } @Override public void onConnectionFailed(ConnectionResult connectionResult) { } } 

I am looking at an error and found its syntax error. Can someone tell me why it doesn't work in compilation?

Answer 1

Your buildGoogleApiClient method cannot be inside your onCreate method.

Change it to:

 protected synchronized void buildGoogleApiClient() { mGoogleApiClient = new GoogleApiClient.Builder(this) .addConnectionCallbacks(this) .addOnConnectionFailedListener(this) .addApi(LocationServices.API) .build(); } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); buildGoogleApiClient (); } 

Or:

 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mGoogleApiClient = new GoogleApiClient.Builder(this) .addConnectionCallbacks(this) .addOnConnectionFailedListener(this) .addApi(LocationServices.API) .build(); } 

Answer 2

 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //ERROR '}' expected protected synchronized void buildGoogleApiClient() { mGoogleApiClient = new GoogleApiClient.Builder(this) .addConnectionCallbacks(this) .addOnConnectionFailedListener(this) .addApi(LocationServices.API) .build(); } } // ERROR 'class' or 'interface' expected 

Must be:

 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } // curly brace to close method and clean up error protected synchronized void buildGoogleApiClient() { mGoogleApiClient = new GoogleApiClient.Builder(this) .addConnectionCallbacks(this) .addOnConnectionFailedListener(this) .addApi(LocationServices.API) .build(); } // removing this curly brace should clear up the error here 

Your syntax is disabled due to unulocal curly braces. Watch out for the little things.

Answer 3

The problem with your code is that you are trying to define a function (buildGoogleApiClient) inside another function (onCreate) that is not possible with Java.

 protected void onCreate(Bundle savedInstanceState) { // // Body of this function // } 

Thus, mainly in Java, curly braces mark the boundaries of a block of code. A code block can be an if-block, while-block or function-block, etc. Java does not allow a function block inside a function block. Only a block class can contain a function block.

So, you need to define your functions directly in the block class.

 public class Blah extends Activity implements BlahInterface { private BlahApiClient mBlahApiClient; protected synchronized void buildBlahApiClient() { mBlahApiClient = new BlahApiClient.Builder(this) .addConnectionCallbacks(this) .addOnConnectionFailedListener(this) .addApi(LocationServices.API) .build(); } protected void onCreate( Bundel savedInstanceState ) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // You can call (execute) any defined function inside this function buildBlahApiClient(); } }