Start Google Maps using intent with specified location

Modify from the last post get latitude and longitude from android.location.Address, start a intent of ACTION_VIEW, with location; to start Google Maps on the location.

package com.AndroidgetFromLocationName;

import java.io.IOException;
import java.util.List;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.location.Address;
import android.location.Geocoder;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

public class AndroidgetFromLocationNameActivity extends Activity {

 EditText searchText;
 Button searchButton;
 ListView listviewResult;
 Button goButton;
 
 Geocoder myGeocoder;
 final static int MAX_RESULT = 10;
 final static String DEFAULT_SEARCH = "London";
 
 double golat, golon;
 boolean govalid;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        searchText = (EditText)findViewById(R.id.searchtext);
        searchText.setText(DEFAULT_SEARCH);
     searchButton = (Button)findViewById(R.id.searchbutton);
     listviewResult = (ListView)findViewById(R.id.listviewresult);
     goButton = (Button)findViewById(R.id.gobutton);
     
     searchButton.setOnClickListener(searchButtonOnClickListener);
     goButton.setOnClickListener(goButtonOnClickListener);
     
     myGeocoder = new Geocoder(this);
     
     //for API Level 9 or higher
     if (!Geocoder.isPresent()){
      Toast.makeText(AndroidgetFromLocationNameActivity.this, 
     "Sorry! Geocoder service not Present.", 
     Toast.LENGTH_LONG).show();
     }
     
     listviewResult.setOnItemClickListener(listviewResultOnItemClickListener);
     
     govalid = false;
    }
    
    Button.OnClickListener goButtonOnClickListener
    = new Button.OnClickListener(){

  @Override
  public void onClick(View arg0) {
   // TODO Auto-generated method stub
   if(govalid){

    final String zoom = "12";
    String stringLoc = "geo:" + golat + "," + golon + "?z=" + zoom;

    Intent intent = new Intent(android.content.Intent.ACTION_VIEW, Uri.parse(stringLoc));
    startActivity(intent);

   }
  }};
    
    OnItemClickListener listviewResultOnItemClickListener
    = new OnItemClickListener(){

  @Override
  public void onItemClick(AdapterView<?> parent, View view, int position,
    long id) {
   // TODO Auto-generated method stub
   
   double lat = ((Address)parent.getItemAtPosition(position)).getLatitude();
   double lon = ((Address)parent.getItemAtPosition(position)).getLongitude();
   String loc = "lat: " + lat + "\n" + "lon: " + lon;
   Toast.makeText(AndroidgetFromLocationNameActivity.this, 
     loc,
     Toast.LENGTH_LONG).show();
   
   govalid = true;
   golat = lat;
      golon = lon;
  }
  
 };
    
    Button.OnClickListener searchButtonOnClickListener
    = new Button.OnClickListener(){

  @Override
  public void onClick(View arg0) {
   // TODO Auto-generated method stub
   String searchString = searchText.getText().toString();
   searchFromLocationName(searchString);
   
   govalid = false;
  }};
  
 private void searchFromLocationName(String name){
  try {
   List<Address> result 
   = myGeocoder.getFromLocationName(name, MAX_RESULT);
   
   if ((result == null)||(result.isEmpty())){
    Toast.makeText(AndroidgetFromLocationNameActivity.this, 
      "No matches were found or there is no backend service!", 
      Toast.LENGTH_LONG).show();
   }else{

    MyArrayAdapter adapter = new MyArrayAdapter(this,
          android.R.layout.simple_list_item_1, result);
    listviewResult.setAdapter(adapter);
    
    Toast.makeText(AndroidgetFromLocationNameActivity.this, 
      "Finished!", 
      Toast.LENGTH_LONG).show();
   }

   
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
   Toast.makeText(AndroidgetFromLocationNameActivity.this, 
     "The network is unavailable or any other I/O problem occurs!", 
     Toast.LENGTH_LONG).show();
  }
 }
 
 public class MyArrayAdapter extends ArrayAdapter<Address> {
  Context mycontext;
  public MyArrayAdapter(Context context, int textViewResourceId,
    List<Address> objects) {
   super(context, textViewResourceId, objects);
   // TODO Auto-generated constructor stub
   mycontext = context; 
  }

  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
   // TODO Auto-generated method stub
   
   int maxAddressLineIndex = getItem(position).getMaxAddressLineIndex();
   String addressLine = "";
   
   for (int j = 0; j <= maxAddressLineIndex; j++){
    addressLine += getItem(position).getAddressLine(j) + ",";
   }
   
   TextView rowAddress = new TextView(mycontext);
   rowAddress.setText(addressLine);
   
   return rowAddress;

  }

 }
 
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
<EditText
    android:id="@+id/searchtext"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    />
<Button
    android:id="@+id/searchbutton"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="Search"
    />
<ListView
 android:id="@+id/listviewresult"
 android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
 />
<Button
    android:id="@+id/gobutton"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="Go"
    />
</LinearLayout>