频道栏目
首页 > 程序开发 > 移动开发 > 其他 > 正文
360插件化方案RePlugin学习:数据持久化
2018-03-07 11:20:19      个评论    来源:brave_shine的博客  
收藏   我要投稿

数据持久化有文件存储、SharedPreferences、数据库存储、ContentProvider、网络存储几种方式。

1.文件存储(不包括缓存目录下存储)、网络存储跟平时使用一样

2.SharedPreferences使用
在“宿主”中存放

val sharedPreferences = applicationContext.getSharedPreferences("testReplugin", Context.MODE_PRIVATE)
sharedPreferences.edit().putString("first","测试").apply()

在“插件”中取出

val sharedPreferences = RePlugin.getHostContext().applicationContext.getSharedPreferences("testReplugin", Context.MODE_PRIVATE)
val s = sharedPreferences.getString("first", "默认")
//弹出提示
Toast.makeText(this, s.toString(), Toast.LENGTH_SHORT).show()

取出的地方弹出的Toast应为“测试”,如果去掉RePlugin.getHostContext(),弹出的就会是“默认”了。

缓存目录下存储与sp文件类似,插件中需要通过RePlugin.getHostContext()获取目录。

3.数据库存储
宿主项目中新建DatabaseOpenHelper.kt

class DatabaseOpenHelper(context: Context) : SQLiteOpenHelper(context, DB_NAME, null, DB_VERSION) {

    companion object {

        private val DB_NAME = "person_list.db"
        val TABLE_NAME = "person"
        private val DB_VERSION = 1
    }

    override fun onCreate(db: SQLiteDatabase) {
        val SQL_CREATE_TABLE = "create table if not exists $TABLE_NAME(_id integer primary key, name varchar(64), description TEXT)"
        db.execSQL(SQL_CREATE_TABLE)
    }

    override fun onUpgrade(db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {

    }
}

用PersonDao.kt作测试

class PersonDao(private val context: Context) {
    private var helper: SQLiteOpenHelper? = null

    fun insert(person: Person) {

        helper = DatabaseOpenHelper(context)

        val db = helper!!.writableDatabase

        db.execSQL("insert into person(name, description) values(?,?)", arrayOf(person.name!!, person.description!!))

        db.close()

        Log.e("dbDao", person.name + ":" + person.description)
    }
}

新建数据库存储对象类,Person.kt

class Person {
    var name: String? = null
    var description: String? = null
}

插件项目中插入数据

    //获取宿主类加载器
    val hostClassLoader = RePlugin.getHostClassLoader()
    //获取Person类
    val person = hostClassLoader.loadClass("com.test.qby.myapplication.pojo.Person")
    //获取Person对象
    val personInstance = person.newInstance()
    //获取set方法
    val nameMethod = person.getDeclaredMethod("setName", String::class.java)
    val descriptionMethod = person.getDeclaredMethod("setDescription", String::class.java)
    //调用set方法,传参
    nameMethod.invoke(personInstance,"数据哈哈")
    descriptionMethod.invoke(personInstance,"试试数据库呵呵")
    //获取PersonDao类
    val personDao = hostClassLoader.loadClass("com.test.qby.myapplication.dao.PersonDao")
    //获取有参构造
    val constructor = personDao.getConstructor(Context::class.java)
    //获取PersonDao对象
    val daoInstance = constructor.newInstance(RePlugin.getHostContext())
    //获取插入方法
    val insertMethod = personDao.getDeclaredMethod("insert", person)
    //调用插入方法
    insertMethod.invoke(daoInstance,personInstance)

通过反射来完成数据库操作。

4.ContentProvider使用
宿主项目中DatabaseOpenHelper.kt同上,然后创建PersonProvider.kt继承ContentProvider

class PersonProvider : ContentProvider() {
    private val TAG = this.javaClass.simpleName

    private var mDatabase: SQLiteDatabase? = null
    private var mContext: Context? = null
    private var mTable: String? = null


    override fun onCreate(): Boolean {
        initProvider()
        return false
    }

    /**
     * 初始化时清除旧数据,插入一条数据
     */
    private fun initProvider() {
        mTable = DatabaseOpenHelper.TABLE_NAME
        mContext = context
        mDatabase = DatabaseOpenHelper(mContext!!).writableDatabase

        Thread(Runnable { mDatabase!!.execSQL("delete from " + mTable!!) }).start()
    }

    override fun query(uri: Uri, projection: Array?, selection: String?,
                       selectionArgs: Array?, sortOrder: String?): Cursor? {
        val tableName = getTableName(uri)
        showLog(tableName + " 查询数据")
        when (mUriMatcher.match(uri)) {
            TABLE_CODE_PERSON //查询所有记录
            -> return mDatabase!!.query(tableName, projection, selection, selectionArgs, null, null, null)
            TABLE_CODE_PERSON_SINGLE//查询特定记录
            -> {
                val where = expendSelection(uri, selection)
                return mDatabase!!.query(tableName, projection, where, selectionArgs, null, null, null)
            }
            else -> throw IllegalArgumentException("wrong uri")
        }
    }

    override fun insert(uri: Uri, values: ContentValues?): Uri? {
        val tableName = getTableName(uri)
        showLog(tableName + " 插入数据")
        val insert = mDatabase!!.insert(tableName, null, values)
        mContext!!.contentResolver.notifyChange(uri, null)
        return Uri.parse(PERSON_CONTENT_URI.toString() + "/" + insert)
    }

    override fun delete(uri: Uri, selection: String?, selectionArgs: Array?): Int {
        val tableName = getTableName(uri)
        showLog(tableName + " 删除数据")

        when (mUriMatcher.match(uri)) {
            TABLE_CODE_PERSON -> {
                val deleteCount = mDatabase!!.delete(tableName, selection, selectionArgs)
                if (deleteCount > 0) {
                    mContext!!.contentResolver.notifyChange(uri, null)
                }
                return deleteCount
            }
            TABLE_CODE_PERSON_SINGLE //删除特定id记录
            -> {
                val where = expendSelection(uri, selection)
                val deleteCount2 = mDatabase!!.delete(tableName, where, selectionArgs)
                if (deleteCount2 > 0) {
                    mContext!!.contentResolver.notifyChange(uri, null)
                }
                return deleteCount2
            }
            else -> throw IllegalArgumentException("wrong uri")
        }
    }


    override fun update(uri: Uri, values: ContentValues?, selection: String?, selectionArgs: Array?): Int {
        val tableName = getTableName(uri)
        showLog(tableName + " 更新数据")
        when (mUriMatcher.match(uri)) {
            TABLE_CODE_PERSON -> return mDatabase!!.update(tableName, values, selection, selectionArgs)
            TABLE_CODE_PERSON_SINGLE //更新特定id记录
            -> {
                val where = expendSelection(uri, selection)
                val updateCount = mDatabase!!.update(tableName, values, where, selectionArgs)
                if (updateCount > 0) {
                    mContext!!.contentResolver.notifyChange(uri, null)
                }
                return updateCount
            }
            else -> throw IllegalArgumentException("wrong uri")
        }

    }

    /**
     * CRUD 的参数是 Uri,根据 Uri 获取对应的表名
     *
     * @param uri URI
     * @return 表名
     */
    private fun getTableName(uri: Uri): String {
        var tableName = ""
        val match = mUriMatcher.match(uri)
        when (match) {
            TABLE_CODE_PERSON_SINGLE, TABLE_CODE_PERSON -> tableName = DatabaseOpenHelper.TABLE_NAME
        }
        showLog("UriMatcher " + uri.toString() + ", result: " + match)
        return tableName
    }

    override fun getType(uri: Uri): String? {
        when (mUriMatcher.match(uri)) {
            TABLE_CODE_PERSON_SINGLE -> return "vnd.android.cursor.item/person"
            TABLE_CODE_PERSON -> return "vnd.android.cursor.dir/person"
        }
        return null
    }


    /**
     * 根据URI和查询条件获取查询子句
     *
     * @param uri       URI
     * @param selection 查询条件
     * @return 查询子句
     */
    private fun expendSelection(uri: Uri, selection: String?): String {
        val split = uri.toString().split("/".toRegex()).dropLastWhile { it.isEmpty() }.toTypedArray()
        val id = java.lang.Long.getLong(split[split.size - 1])!!
        var where = "id=" + id
        if (!TextUtils.isEmpty(selection)) {
            where += " and " + selection!!
        }
        return where
    }

    private fun showLog(s: String) {
        Log.d(TAG, s + " : " + Thread.currentThread().name)
    }

    companion object {
        private val mUriMatcher = UriMatcher(UriMatcher.NO_MATCH)
        val AUTHORITY = "com.test.qby.myapplication.provider.PersonProvider"  //授权
        val PERSON_CONTENT_URI = Uri.parse("content://$AUTHORITY/person")

        private val TABLE_CODE_PERSON_SINGLE = 1
        private val TABLE_CODE_PERSON = 2

        init {
            //关联不同的 URI 和 code,便于后续 getType
            mUriMatcher.addURI(AUTHORITY, "person", TABLE_CODE_PERSON)
            //匹配:content://com.test.qby.myapplication.provider.PersonProvider/person/数字,返回值为1
            mUriMatcher.addURI(AUTHORITY, "person/#", TABLE_CODE_PERSON_SINGLE)
        }
    }
}

在清单文件中注册

插件中操作Provider

        //ContentProvider
        //内容提供者URI
        val uri = Uri.parse("content://com.test.qby.myapplication.provider.PersonProvider/person")
        //数据
        val values = ContentValues()
        values.put("name", "yyy")
        values.put("description", "你猜我猜不猜你是谁")
        //插入操作
        val insert = PluginProviderClient.insert(RePlugin.getHostContext(),uri, values)
        Log.e(TAG, insert.toString())
        //查询操作,获得游标
        val cursor = PluginProviderClient.query(RePlugin.getHostContext(),uri, arrayOf("name","description"), null, null, "DESC")
        Log.e(TAG, "查询条目数".plus(cursor.count))
        //根据查询结果,循环打印结果
        if(cursor.moveToNext()){
            val name = cursor.getString(cursor.getColumnIndex("name"))
            val description = cursor.getString(cursor.getColumnIndex("description"))
            Log.e(TAG, "name = $name,description = $description")
        }
        //关闭游标
        cursor.close()

用到反射的地方写起来代码比较多,真正用的时候还是要抽取放到工具类里,优化一下代码。

点击复制链接 与好友分享!回本站首页
上一篇:UE4 灯光阴影
下一篇:360插件化方案RePlugin学习:资源共享
相关文章
图文推荐

关于我们 | 联系我们 | 广告服务 | 投资合作 | 版权申明 | 在线帮助 | 网站地图 | 作品发布 | Vip技术培训 | 举报中心

版权所有: 红黑联盟--致力于做实用的IT技术学习网站