This tutorial is also available in german at my android weblog Androidianer.de

Hey there,

I've written this tutorial, because there were a lot of questions in the android-group and in this forum about the functionality of the Geocoder Class and the possibility to convert an address in the longitude and latitude.
I hope this tutorial can clarify the most problems.

What the application can do:
Convert an entered address in longitude and latitude and display it in a map.

How it looks like:


Here we go:

1. Create a nice layout in the main.xml. I will not explain XML-layouting here, cause there are a lot of good tutorials from plusminus in this forum. Donwload the attached source code to see my main.xml

2. Add the following permissions to the Manifest.xml over the <application> Tag



3. Have fun with java. It's so easy with GeoCoder class:

All you have to do is:
- Create a new Geocoder instance


- Write a OnClickListener for the search button (btnSearch) and get the entered address from the EditText-field (address)


- Let the GeoCoder class search for the entered address (don't forget the try-catch-statement)


- Get the longitude and latitude from the found addresses and display the map (see full source code for the navigateToLocation function)



Full Source
The full source also displays an error if the address wasn't found (check also the attachment for manifest and main.xml):



I hope this demonstrates how easy it is to convert an address in long/lat with GeoCoder.
See the GoogleMaps Mini Tutorial from lordhong if you want to add more features to your application.
But with GeoCoder you mustn't use strange Yahoo-API requests

Thanks to plusminus for his great tutorials. Hope I can give something back with this one.

[Edit:] When you read the APIs you will see that it is recommended to put the getFromLocation() method in an own thread. Read the Simple GoogleMaps with Threads tutorial to see how it works.

Greetings from Germany
Mic

Hey michels,

thank you for contributing to the community and greetings back to Germany (I'm German too).
Nice step-by-step example
-
Best Regards,
plusminus

Btw, as the GeoCoder does a blocking network-query, it should be placed in a Thread, as otherwise the UI will be unavailable until it returns

plusminus wrote:Btw, as the GeoCoder does a blocking network-query, it should be placed in a Thread, as otherwise the UI will be unavailable until it returns

Hey plusminus,

you're right. I read that too, but I'm not an expert in threads so far and I thought it's too complicated to explain GeoCoder and threads in one tutorial.

So I wrote a seperate tutorial for threads last night.

Simple GoogleMaps with threads

Hope that I understand everything right.

greetings
Mic

Yeah thats fine. See my comment over there.

I usually do such thing with

because then I don't have to create a new Handler, create message, handle with what-ids and stuff. So its a bit simpler.

Regards,
plusminus

hi
i am getting following exception
" Unable to parse response from server" when i search for London.
here is the snippet
try
{
foundAdresses = gc.getFromLocationName(addressInput, 5); // Search
// addresses
Thread.sleep(1500);
}
catch (Exception e)
{
// @todo: Show error message
Log.i("TEST", "exception in thread " + e.getMessage());
}
even as i observe after first search its sending this exception evry time for any location.

hie michels ,

Thanks very much for this tutorial, Its very much helpful for me.
But whenver I run it shows nothing after clicking on the "GO" button.
I can see only the map, not the exact location.

Please suggest me.

~Dhr

hie michels ,

Thanks for this good tutorial,But whenver I run it shows 'service unavailable'.

Please suggest me.

Poornima S

poornima_s wrote:hie michels ,

Thanks for this good tutorial,But whenver I run it shows 'service unavailable'.

Please suggest me.

Poornima S

I found on the Internet that this is an emulator bug, try it on a real device, it might be working. It was my case actually .

just wanted to say thanks for very helpful tutorial. When using Google Maps API 8, had same "no service" problem as previously posted, but when I reverted to Google Maps API 7, worked fine. (Here's link to website that tipped me off: http://osdir.com/ml/Android-Developers/ ... 00293.html)

Thanks again.

michels wrote:

GoogleMaps with Geocoder Class

This tutorial is also available in german at my android weblog Androidianer.de

Hey there,

I've written this tutorial, because there were a lot of questions in the android-group and in this forum about the functionality of the Geocoder Class and the possibility to convert an address in the longitude and latitude.
I hope this tutorial can clarify the most problems.

What the application can do:
Convert an entered address in longitude and latitude and display it in a map.

How it looks like:

Here we go:

1. Create a nice layout in the main.xml. I will not explain XML-layouting here, cause there are a lot of good tutorials from plusminus in this forum. Donwload the attached source code to see my main.xml

2. Add the following permissions to the Manifest.xml over the <application> Tag

Syntax: [ Download ] [ Hide ]

Syntax: [ Download ] [ Show ]

Using xml Syntax Highlighting

1. <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
2. <uses-permission android:name="android.permission.INTERNET" />
3.  

Parsed in 0.001 seconds, using GeSHi 1.0.8.4

3. Have fun with java. It's so easy with GeoCoder class:

All you have to do is:
- Create a new Geocoder instance

Syntax: [ Download ] [ Hide ]

Syntax: [ Download ] [ Show ]

Using java Syntax Highlighting

1. gc = new Geocoder(this); //create new geocoder instance
2.  

Parsed in 0.035 seconds, using GeSHi 1.0.8.4

- Write a OnClickListener for the search button (btnSearch) and get the entered address from the EditText-field (address)

Syntax: [ Download ] [ Hide ]

Syntax: [ Download ] [ Show ]

Using java Syntax Highlighting

1. gc = new Geocoder(this); //create new geocoder instance
2. btnSearch.setOnClickListener(new OnClickListener() {
3.   public void onClick(View v) {
4.     String addressInput = adress.getText().toString(); //Get input text
5.   }
6. });
7.  

Parsed in 0.036 seconds, using GeSHi 1.0.8.4

- Let the GeoCoder class search for the entered address (don't forget the try-catch-statement)

Syntax: [ Download ] [ Hide ]

Syntax: [ Download ] [ Show ]

Using java Syntax Highlighting

1. gc = new Geocoder(this); //create new geocoder instance
2. btnSearch.setOnClickListener(new OnClickListener() {
3.   public void onClick(View v) {
4.     String addressInput = adress.getText().toString(); //Get input text
5.     try {
6.       List<Address> foundAdresses = gc.getFromLocationName(addressInput, 5); //Search addresses
7.     }
8.     catch (Exception e) {
9.       //@todo: Show error message
10.     }
11.   }
12. });
13.  

Parsed in 0.037 seconds, using GeSHi 1.0.8.4

- Get the longitude and latitude from the found addresses and display the map (see full source code for the navigateToLocation function)

Syntax: [ Download ] [ Hide ]

Syntax: [ Download ] [ Show ]

Using java Syntax Highlighting

1. gc = new Geocoder(this); //create new geocoder instance
2. btnSearch.setOnClickListener(new OnClickListener() {
3.   public void onClick(View v) {
4.     String addressInput = adress.getText().toString(); //Get input text
5.     try {
6.       List<Address> foundAdresses = gc.getFromLocationName(addressInput, 5); //Search addresses
7.       for (int i = 0; i < foundAdresses.size(); ++i) {
8.         //Save results as Longitude and Latitude
9.         //@todo: if more than one result, then show a select-list
10.         Address x = foundAdresses.get(i);
11.         lat = x.getLatitude();
12.         lon = x.getLongitude();
13.       }
14.       navigateToLocation((lat * 1000000), (lon * 1000000), myMap); //display the found address
15.     }
16.     catch (Exception e) {
17.       //@todo: Show error message
18.     }
19.   }
20. });
21.  

Parsed in 0.039 seconds, using GeSHi 1.0.8.4

Full Source
The full source also displays an error if the address wasn't found (check also the attachment for manifest and main.xml):

Syntax: [ Download ] [ Hide ]

Syntax: [ Download ] [ Show ]

Using java Syntax Highlighting

1. //Lot's of imports here... see full source
2.  
3. public class simpleGoogleMaps extends MapActivity {
4.   protected boolean isRouteDisplayed() { return false; }
5.   private MapView myMap;
6.   private Button btnSearch;
7.   private EditText adress;
8.   private Geocoder gc;
9.   private double lat;
10.   private double lon;
11.        
12.        
13.   @Override
14.   public void onCreate(Bundle savedInstanceState) {
15.     super.onCreate(savedInstanceState);
16.     setContentView(R.layout.main);
17.        
18.     myMap = (MapView) findViewById(R.id.simpleGM_map); //Get map from XML
19.     btnSearch = (Button) findViewById(R.id.simpleGM_btn_search); //Get button from XML
20.     adress = (EditText) findViewById(R.id.simpleGM_adress); //Get address from XML
21.        
22.     gc = new Geocoder(this); //create new geocoder instance
23.                
24.     btnSearch.setOnClickListener(new OnClickListener() {
25.       public void onClick(View v) {
26.         String addressInput = adress.getText().toString(); //Get input text
27.                                
28.         try {
29.                                        
30.           List<Address> foundAdresses = gc.getFromLocationName(addressInput, 5); //Search addresses
31.                                        
32.           if (foundAdresses.size() == 0) { //if no address found, display an error
33.             Dialog locationError = new AlertDialog.Builder(simpleGoogleMaps.this)
34.               .setIcon(0)
35.               .setTitle("Error")
36.               .setPositiveButton(R.string.ok, null)
37.               .setMessage("Sorry, your address doesn't exist.")
38.               .create();
39.             locationError.show();
40.           }
41.           else { //else display address on map
42.             for (int i = 0; i < foundAdresses.size(); ++i) {
43.               //Save results as Longitude and Latitude
44.               //@todo: if more than one result, then show a select-list
45.               Address x = foundAdresses.get(i);
46.               lat = x.getLatitude();
47.               lon = x.getLongitude();
48.             }
49.           navigateToLocation((lat * 1000000), (lon * 1000000), myMap); //display the found address
50.           }
51.         }
52.         catch (Exception e) {
53.           //@todo: Show error message
54.         }
55.                                
56.       }
57.     });
58.     }
59.    
60.   /**
61.   * Navigates a given MapView to the specified Longitude and Latitude
62.   */
63.   public static void navigateToLocation (double latitude, double longitude, MapView mv) {
64.     GeoPoint p = new GeoPoint((int) latitude, (int) longitude); //new GeoPoint
65.     mv.displayZoomControls(true); //display Zoom (seems that it doesn't work yet)
66.     MapController mc = mv.getController();
67.     mc.animateTo(p); //move map to the given point
68.     int zoomlevel = mv.getMaxZoomLevel(); //detect maximum zoom level
69.     mc.setZoom(zoomlevel - 1); //zoom
70.     mv.setSatellite(false); //display only "normal" mapview    
71.   }
72. }
73.  

Parsed in 0.047 seconds, using GeSHi 1.0.8.4

I hope this demonstrates how easy it is to convert an address in long/lat with GeoCoder.
See the GoogleMaps Mini Tutorial from lordhong if you want to add more features to your application.
But with GeoCoder you mustn't use strange Yahoo-API requests

Thanks to plusminus for his great tutorials. Hope I can give something back with this one.

[Edit:] When you read the APIs you will see that it is recommended to put the getFromLocation() method in an own thread. Read the Simple GoogleMaps with Threads tutorial to see how it works.

Greetings from Germany
Mic

Really an amazing information post. You can understand easily and quickly. Thanks for sharing.

Anyone can help me. I m getting the error java.io.IOException: unable to parse response from server .
I m also getting my custom error on finding any place like india, london , etc in between.
I tried a lot to fix it but unable to fix it.

Hey everyone

Great tut. Thanks.

I am only getting one search result from the Geocoder's .getFromLocationName("address", 5). I think it is returning results based on my phones locale, but I don't know how to override it.

eg. I live in the UK, and if I search for 'Canterbury', it only returns Canterbury, UK; and not Canterbury, New Zealand.

No matter what I search for (when using search terms that should get multiple results), I only get one.

Anybody know how to get past this?

Thanks for this explanation, Michels. Helped me a lot!

how can this code run in api 8?