public class HashMap<K, V> extends AbstractMap<K, V> implements Cloneable, Serializable {...}
public class Hashtable<K, V> extends Dictionary<K, V> implements Map<K, V>, Cloneable, Serializable {...}

public abstract class AbstractMap<K, V> implements Map<K, V> {...}

/**
 * Called when an activity you launched exits, giving you the requestCode
 * you started it with, the resultCode it returned, and any additional
 * data from it.  The <var>resultCode</var> will be
 * {@link #RESULT_CANCELED} if the activity explicitly returned that,
 * didn't return any result, or crashed during its operation.
 *
 * <p>You will receive this call immediately before onResume() when your
 * activity is re-starting.
 *
 * <p>This method is never invoked if your activity sets
 * {@link android.R.styleable#AndroidManifestActivity_noHistory noHistory} to
 * <code>true</code>.
 *
 * @param requestCode The integer request code originally supplied to
 *                    startActivityForResult(), allowing you to identify who this
 *                    result came from.
 * @param resultCode The integer result code returned by the child activity
 *                   through its setResult().
 * @param data An Intent, which can return result data to the caller
 *               (various data can be attached to Intent "extras").
 *
 * @see #startActivityForResult
 * @see #createPendingResult
 * @see #setResult(int)
 */
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
}

//第一个参数是Activity所在的package包名，第二个参数是完整的Class类名（包括包路径）
ComponentName componetName = new ComponentName("com.cybo3d.cybox.miya", 			  
								"com.cybo3d.cybox.miya.MainActivity");
Intent intent = new Intent();
intent.setComponent(componetName);
startActivity(intent);

public static File saveImage(Bitmap bmp) {
    File appDir = new File(Environment.getExternalStorageDirectory(), "Boohee");
    if (!appDir.exists()) {
        appDir.mkdir();
    }
    String fileName = System.currentTimeMillis() + ".jpg";
    File file = new File(appDir, fileName);
    try {
        FileOutputStream fos = new FileOutputStream(file);
        bmp.compress(CompressFormat.JPEG, 100, fos);
        fos.flush();
        fos.close();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

155.     @Override  
156.     public boolean onKeyDown(int keyCode, KeyEvent event)   
157.     {   
158.         Log.d("onKeyDown:", " keyCode=" + keyCode + " KeyEvent=" + event);   
159.         switch (keyCode)   
160.         {   
161.             case KeyEvent.KEYCODE_DPAD_UP:   
162.   
163.             break;   
164.             case KeyEvent.KEYCODE_DPAD_DOWN:   
165.   
166.             break;   
167.             case KeyEvent.KEYCODE_DPAD_LEFT:   
168.                 //右左按键可以控制第一进度的增减   
169.                 pb.setProgress( pb.getProgress()-5 );   
170.             break;   
171.             case KeyEvent.KEYCODE_DPAD_RIGHT:   
172.                 pb.setProgress( pb.getProgress()+5 );   
173.             break;   
174.             case KeyEvent.KEYCODE_DPAD_CENTER:   
175.   
176.             break;   
177.             case KeyEvent.KEYCODE_0:   
178.             break;   
179.         }   
180.         return super.onKeyDown(keyCode, event);   
181.     }   
182. }