SavingStateActivity.java

package com.google.mcommerce.sample.android.chapter07.preferences;

// This file is MainActivity.java
import android.app.Activity;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.os.Bundle;
import android.util.Log;

import com.google.mcommerce.sample.android.R;

public class SavingStateActivity extends Activity {

	private static final String TAG = "SavingState";
	final String INITIALIZED = "initialized";
	private String someString;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		SharedPreferences myPrefs = getPreferences(MODE_PRIVATE);

		boolean hasPreferences = myPrefs.getBoolean(INITIALIZED, false);

		if (hasPreferences) {
			Log.v(TAG, "We've been called before");
			// Read other values as desired from preferences file�
			someString = myPrefs.getString("someString", "");
		} else {
			Log.v(TAG, "First time ever being called");
			// Set up initial values for what will end up
			// in the preferences file
			someString = "some default value";
		}

		Log.v(TAG, "someString = " + someString);

		// Later when ready to write out values
		Editor editor = myPrefs.edit();
		editor.putBoolean(INITIALIZED, true);
		editor.putString("someString", someString);
		// Write other values as desired
		editor.commit();
	}
}