Usage

public class SpCacheApplication extends Application
{
    @Override
    public void onCreate()
    {
        super.onCreate();
        SpCache.init(this);
    }
}

SpCache.getInt(ACTIVITY_CREATE_COUNT, 0);
SpCache.putInt(ACTIVITY_CREATE_COUNT, 1);

代码

import android.content.Context;
import android.content.SharedPreferences;
import android.os.AsyncTask;
import android.util.Log;

import java.lang.ref.SoftReference;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

/**
 * Created by zhy on 15/5/18.
 */
public class SpCache
{
    private static final String TAG = SpCache.class.getSimpleName();
    private static SpCache INSTANCE;
    private ConcurrentMap<String, SoftReference<Object>> mCache;
    private String mPrefFileName = "com.zhy.spcache";
    private Context mContext;

    private SpCache(Context context, String prefFileName)
    {
        mContext = context.getApplicationContext();
        mCache = new ConcurrentHashMap<String, SoftReference<Object>>();
        initDatas(prefFileName);

    }

    private void initDatas(String prefFileName)
    {
        if (null != prefFileName && prefFileName.trim().length() > 0)
        {
            mPrefFileName = prefFileName;
        } else
        {
            Log.d(TAG, "prefFileName is invalid , we will use default value ");
        }
        //SharedPreferences sp = mContext.getSharedPreferences(mPrefFileName, Context.MODE_PRIVATE);
        //Map<String, ?> alreadyDatas = sp.getAll();
        //Set<String> keys = alreadyDatas.keySet();
        //for (String key : keys)
        //{
        //    mCache.put(key, new SoftReference<Object>(alreadyDatas.get(key)));
        //}
    }

    public static SpCache init(Context context, String prefFileName)
    {
        if (INSTANCE == null)
        {
            synchronized (SpCache.class)
            {
                if (INSTANCE == null)
                {
                    INSTANCE = new SpCache(context, prefFileName);
                }
            }
        }
        return INSTANCE;
    }

    public static SpCache init(Context context)
    {
        return init(context, null);
    }

    private static SpCache getInstance()
    {
        if (INSTANCE == null)
            throw new NullPointerException("you show invoke SpCache.init() before you use it ");

        return INSTANCE;
    }


    //put

    public static SpCache putInt(String key, int val)
    {
        return getInstance().put(key, val);
    }

    public static SpCache putLong(String key, long val)
    {
        return getInstance().put(key, val);
    }

    public static SpCache putString(String key, String val)
    {
        return getInstance().put(key, val);
    }

    public static SpCache putBoolean(String key, boolean val)
    {
        return getInstance().put(key, val);
    }

    public static SpCache putFloat(String key, float val)
    {
        return getInstance().put(key, val);
    }


    //get
    public static int getInt(String key, int defaultVal)
    {
        return (int) (getInstance().get(key, defaultVal));
    }

    public static long getLong(String key, long defaultVal)
    {
        return (long) (getInstance().get(key, defaultVal));
    }

    public static String getString(String key, String defaultVal)
    {
        return (String) (getInstance().get(key, defaultVal));
    }

    public static boolean getBoolean(String key, boolean defaultVal)
    {
        return (boolean) (getInstance().get(key, Boolean.class));
    }

    public static float getFloat(String key, float defaultVal)
    {
        return (float) (getInstance().get(key, defaultVal));
    }

    //contains
    public boolean contains(String key)
    {
        return mCache.get(key).get() != null ? true : getSharedPreferences().contains(key);
    }

    //remove
    public static SpCache remove(String key)
    {
        return INSTANCE._remove(key);
    }

    private SpCache _remove(String key)
    {
        mCache.remove(key);
        SharedPreferences.Editor editor = getSharedPreferences().edit();
        editor.remove(key);
        SharedPreferencesCompat.apply(editor);
        return INSTANCE;
    }

    //clear
    public static SpCache clear()
    {
        return INSTANCE._clear();
    }

    private SpCache _clear()
    {
        mCache.clear();
        SharedPreferences.Editor editor = getSharedPreferences().edit();
        editor.clear();
        SharedPreferencesCompat.apply(editor);
        return INSTANCE;
    }

    private <T> SpCache put(String key, T t)
    {
        mCache.put(key, new SoftReference<Object>(t));
        SharedPreferences.Editor editor = getSharedPreferences().edit();
        if (t instanceof String)
        {
            editor.putString(key, (String) t);
        } else if (t instanceof Integer)
        {
            editor.putInt(key, (Integer) t);
        } else if (t instanceof Boolean)
        {
            editor.putBoolean(key, (Boolean) t);
        } else if (t instanceof Float)
        {
            editor.putFloat(key, (Float) t);
        } else if (t instanceof Long)
        {
            editor.putLong(key, (Long) t);
        } else
        {
            Log.d(TAG, "you may be put a invalid object :" + t);
            editor.putString(key, t.toString());
        }

        SharedPreferencesCompat.apply(editor);
        return INSTANCE;
    }


    private Object readDisk(String key, Object defaultObject)
    {
        Log.e("TAG", "readDisk");
        SharedPreferences sp = getSharedPreferences();

        if (defaultObject instanceof String)
        {
            return sp.getString(key, (String) defaultObject);
        } else if (defaultObject instanceof Integer)
        {
            return sp.getInt(key, (Integer) defaultObject);
        } else if (defaultObject instanceof Boolean)
        {
            return sp.getBoolean(key, (Boolean) defaultObject);
        } else if (defaultObject instanceof Float)
        {
            return sp.getFloat(key, (Float) defaultObject);
        } else if (defaultObject instanceof Long)
        {
            return sp.getLong(key, (Long) defaultObject);
        }
        Log.e(TAG, "you can not read object , which class is " + defaultObject.getClass().getSimpleName());
        return null;

    }

    private Object get(String key, Object defaultVal)
    {
        SoftReference reference = mCache.get(key);
        Object val = null;
        if (null == reference || null == reference.get())
        {
            val = readDisk(key, defaultVal);
            mCache.put(key, new SoftReference<Object>(val));
        }
        val = mCache.get(key).get();
        return val;
    }


    /**
     * 创建一个解决SharedPreferencesCompat.apply方法的一个兼容类
     *
     * @author zhy
     */
    private static class SharedPreferencesCompat
    {
        private static final Method sApplyMethod = findApplyMethod();

        /**
         * 反射查找apply的方法
         *
         * @return
         */
        @SuppressWarnings({"unchecked", "rawtypes"})
        private static Method findApplyMethod()
        {
            try
            {
                Class clz = SharedPreferences.Editor.class;
                return clz.getMethod("apply");
            } catch (NoSuchMethodException e)
            {
            }

            return null;
        }

        /**
         * 如果找到则使用apply执行，否则使用commit
         *
         * @param editor
         */
        public static void apply(final SharedPreferences.Editor editor)
        {
            try
            {
                if (sApplyMethod != null)
                {
                    sApplyMethod.invoke(editor);
                    return;
                }
            } catch (IllegalArgumentException e)
            {
            } catch (IllegalAccessException e)
            {
            } catch (InvocationTargetException e)
            {
            }

            new AsyncTask<Void, Void, Void>()
            {

                @Override
                protected Void doInBackground(Void... params)
                {
                    editor.commit();
                    return null;
                }
            };
        }
    }


    private SharedPreferences getSharedPreferences()
    {
        return mContext.getSharedPreferences(mPrefFileName, Context.MODE_PRIVATE);
    }


}