最佳实践系列 -- Android持久化存储

Android持久化数据存储就像访问Static变量一样简单，可完全取代SharedPreferences的存储功能。支持List<*>、Map<*,*>、String、Int、Long、Float、Double和Java Been等。

源码地址：https://github.com/chockqiu/DataStoreProxy

使用步骤

使用步骤极其简单，只需要定义好字段名称及类型便可使用。

定义举例

inline val mDataStoreConfigs: DataStoreConfig get() = DataStoreConfig.instance
class DataStoreConfig {
    //定义一个默认值为""的字段 -- name
    var name by property("")

    companion object {
        val instance by lazy { return@lazy DataStoreConfig() }
    }
}

使用举例

//存储
mDataStoreConfigs.name = "Zhang San"

//读取
textview.text = mDataStoreConfigs.name

其他类型数据举例

//定义一个默认值为false的Boolean字段 -- expBoolean
var expBoolean by property(false)
//定义一个默认值为0的Int字段 -- expInt
var expInt by property(0)
//定义一个默认值为0的Long字段 -- expLong
var expLong by property(0L)
//定义一个默认值为0的Float字段 -- expFloat
var expFloat by property(0.0f)
//定义一个默认值为0的Double字段 -- expDouble
var expDouble by property(0.0)
//定义一个默认值为[0, 1, 2, 3, 4, 5]的byte[]数组字段 -- expBytes
var expBytes by property(byteArrayOf(0, 1, 2, 3, 4, 5))
//定义一个默认值为Java been -- ExpBeen字段 -- expBeen 
var expBeen by property(ExpBeen())
//定义一个默认值为空的Map字段 -- expMap 
var expMap by jsonProperty(object : TypeReference<Map<String, ExpBeen>>() {},mutableMapOf())
//定义一个默认值为空的List字段 -- expList 
var expList by jsonProperty(object : TypeReference<MutableList<ExpBeen>>() {},mutableListOf())

底层实现

目前持久化存储采用的是微信的MMKV，拥有不错的稳定性及存储性能。什么是MMKV？ 点击链接

class MMKVDataStore(name: String) : DataStore {

    private var mmkv: MMKV = MMKV.mmkvWithID(name)

    override fun clearAll() {
        mmkv.clearAll()
    }

    override fun delete(key: String) {
        mmkv.removeValueForKey(key)
    }

    override fun write(key: String, obj: Any): Boolean {
        return if (obj is String) {
            mmkv.encode(key, obj)
        } else if (obj is Int) {
            mmkv.encode(key, obj)
        } else if (obj is Boolean) {
            mmkv.encode(key, obj)
        } else if (obj is Float) {
            mmkv.encode(key, obj)
        } else if (obj is Long) {
            mmkv.encode(key, obj)
        } else if (obj is Double) {
            mmkv.encode(key, obj)
        } else if (obj is ByteArray) {
            mmkv.encode(key, obj)
        } else if (obj is Parcelable) {
            mmkv.encode(key, obj)
        } else {
            mmkv.encode(key, JSON.toJSONString(obj))
        }
    }

    override fun readString(key: String, def: String?): String? {
        return mmkv.decodeString(key, def)
    }

    override fun readBoolean(key: String, def: Boolean): Boolean {
        return mmkv.decodeBool(key, def)
    }

    override fun readInt(key: String, def: Int): Int {
        return mmkv.decodeInt(key, def)
    }

    override fun readLong(key: String, def: Long): Long {
        return mmkv.decodeLong(key, def)
    }

    override fun readFloat(key: String, def: Float): Float {
        return mmkv.decodeFloat(key, def)
    }

    override fun readDouble(key: String, def: Double): Double {
        return mmkv.decodeDouble(key, def)
    }

    override fun readBytes(key: String, def: ByteArray?): ByteArray? {
        return mmkv.decodeBytes(key, def)
    }
}

使用远程依赖

在工程根目录的build.gradle中添加

allprojects {
    repositories {
        maven { url 'https://www.jitpack.io' }
        ...
    }
}

添加依赖

implementation 'com.github.chockqiu:DataStoreProxy:1.1'