SharedPreferences getString異常

開發過程中遇到的一個問題，由於項目程序中大量使用sharedpreferences做緩存。而且，key沒有統一管理，就出現了這個問題。

異常信息：

05-11 09:10:01.991: E/AndroidRuntime(17032): Caused by: java.lang.ClassCastException: java.lang.Boolean cannot be cast to java.lang.String
05-11 09:10:01.991: E/AndroidRuntime(17032): at android.app.SharedPreferencesImpl.getString(SharedPreferencesImpl.java:223)
05-11 09:10:01.991: E/AndroidRuntime(17032): at com.ronindong.ztemp.MainActivity.onCreate(MainActivity.java:60)
05-11 09:10:01.991: E/AndroidRuntime(17032): at android.app.Activity.performCreate(Activity.java:6051)
05-11 09:10:01.991: E/AndroidRuntime(17032): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
05-11 09:10:01.991: E/AndroidRuntime(17032): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2281)
05-11 09:10:01.991: E/AndroidRuntime(17032): ... 10 more

java代碼：

private final staitc KEY_TEST = "key_test_";
SharedPreferences sp = getSharedPreferences("test", Context.MODE_PRIVATE);

//key放入的是boolean類型的值
sp.edit().putBoolean(KEY_TEST, false).commit();

//同一個key，取出string值
String string = sp.getString(KEY_TEST, "");