public class SpInstance {

    /**
     * SP_NAME             sp的名称
     * applicationContext  上下文
     * sharedPreferences   sp
     */
    public static final String SP_NAME = "my_sp_config";
    private Context applicationContext = null;
    private SharedPreferences sharedPreferences = null;

    public static final int ERROR_CODE = -1;

    /**
     * instance       单例
     * INSTANCE_LOCK  互斥锁
     */
    private static SpInstance instance = null;
    private static final Object INSTANCE_LOCK = new Object();

    /**
     * 获取单例
     *
     * @return
     */
    public static SpInstance getInstance() {
        if (instance == null) {
            synchronized (INSTANCE_LOCK) {
                if (instance == null) {
                    instance = new SpInstance();
                }
            }
        }
        return instance;
    }


    /**
     * 初始化
     *
     * @param context
     */
    public void init(Context context) {
        this.applicationContext = context.getApplicationContext();
    }


    /**
     * 获取 sp
     *
     * @return
     */
    private SharedPreferences getSp() {
        if (sharedPreferences == null) {
            sharedPreferences = applicationContext.getSharedPreferences(SP_NAME, Context.MODE_PRIVATE);
        }
        return sharedPreferences;
    }

    /**
     * 获取编辑
     *
     * @return
     */
    private SharedPreferences.Editor getEdit() {
        return getSp().edit();
    }


    /**
     * 存值至 sp
     *
     * @param key
     * @param value
     * @param <T>
     */
    public <T> void put(String key, T value) {
        if (getEdit() != null) {
            if (value instanceof Boolean) {
                getEdit().putBoolean(key, (Boolean) value).commit();
            } else if (value instanceof String) {
                getEdit().putString(key, (String) value).commit();
            } else if (value instanceof Integer) {
                getEdit().putInt(key, (Integer) value).commit();
            } else if (value instanceof Float) {
                getEdit().putFloat(key, (Float) value).commit();
            } else if (value instanceof Long) {
                getEdit().putLong(key, (Long) value).commit();
            }
        }
    }


    public boolean getBoolean(String key, boolean defaultValue) {
        if (getSp() != null) {
            return getSp().getBoolean(key, defaultValue);
        }
        return false;
    }

    public String getString(String key, String defaultValue) {
        if (getSp() != null) {
            return getSp().getString(key, defaultValue);
        }
        return "";
    }

    public int getInt(String key, int defaultValue) {
        if (getSp() != null) {
            return getSp().getInt(key, defaultValue);
        }
        return ERROR_CODE;
    }

    public float getFloat(String key, float defaultValue) {
        if (getSp() != null) {
            return getSp().getFloat(key, defaultValue);
        }
        return ERROR_CODE;
    }

    public long getLong(String key, long defaultValue) {
        if (getSp() != null) {
            return getSp().getLong(key, defaultValue);
        }
        return ERROR_CODE;
    }

}