一、Activity

public class ActivityMain extends Activity{
	private EditText edt_hour;
	private EditText edt_minute;
	private EditText edt_second;
	
	TextWatcher tw = new TextWatcher(){

		//@Override

		public void beforeTextChanged(CharSequence s, int start, int count,int after){ 

		}

		//@Override

		public void onTextChanged(CharSequence s, int start, int before, int count){ 

		}

		//@Override

		public void afterTextChanged(Editable s){

			if(s.toString().length() == 2){ 

				if(edt_hour.isFocused()){ 

					edt_hour.clearFocus();

					edt_minute.requestFocus();

				}

				else if(edt_minute.isFocused()){ 
					edt_minute.clearFocus(); 
					edt_second.requestFocus();
				}

				else if(edt_second.isFocused()){ 
					edt_second.clearFocus(); 
				} 
			}
		}
	};

	

	public void onCreate(Bundle savedInstanceState)  { 
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		edt_hour = (EditText) findViewById(R.id.hour);   
		edt_hour.addTextChangedListener(tw); 
		edt_minute = (EditText) findViewById(R.id.minute); 
		edt_minute.addTextChangedListener(tw);
		edt_second = (EditText) findViewById(R.id.second); 
		edt_second.addTextChangedListener(tw);
	}
}

二、xml布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout  
  xmlns:android="http://schemas.android.com/apk/res/android"   
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"     	
  android:orientation="vertical">
  
   <EditText   
	android:id="@+id/hour"  
  	android:text="00"   
	android:maxLength="2"
	android:inputType="number"   
  	android:selectAllOnFocus="true" 
  	android:layout_width="fill_parent" 
  	android:layout_height="wrap_content"/>
  	
  <EditText   
	android:id="@+id/minute"  
	android:text="00" 
	android:maxLength="2"  
	android:inputType="number"
	android:selectAllOnFocus="true" 
	android:layout_width="fill_parent" 
	android:layout_height="wrap_content"/> 
	
  <EditText android:maxLength="2" 
 	android:inputType="number" 
 	android:text="00" 
 	android:id="@+id/second" 
 	android:selectAllOnFocus="true" 
 	android:layout_width="fill_parent" 
 	android:layout_height="wrap_content"/>

</LinearLayout>