Android jetpack room 数据库管理工具的配置及使用

发布时间：2023-05-15 14:54:05

本文字数：369 字 阅读完需：约 3 分钟

配置

在根目录的build.gradle的plugin下添加

id 'com.google.devtools.ksp' version '1.8.21-1.0.11' apply false

注意，版本号1.8.21要与org.jetbrains.kotlin.android版本号一致。示例:

/build.gradle

plugins {
    id 'com.android.application' version '8.0.1' apply false
    id 'com.android.library' version '8.0.1' apply false
    id 'org.jetbrains.kotlin.android' version '1.8.21' apply false
    id 'com.google.devtools.ksp' version '1.8.21-1.0.11' apply false
}

在app/build.gradle下添加

 def room_version = "2.5.0"

    implementation "androidx.room:room-runtime:$room_version"
    annotationProcessor "androidx.room:room-compiler:$room_version"

    // To use Kotlin Symbol Processing (KSP)
    ksp "androidx.room:room-compiler:$room_version"


    // optional - Test helpers
    testImplementation "androidx.room:room-testing:$room_version"

将jvm版本改为17

 compileOptions {
        sourceCompatibility JavaVersion.VERSION_17
        targetCompatibility JavaVersion.VERSION_17
    }
    kotlinOptions {
        jvmTarget = '17'
    }

示例: app/build.gradle

plugins {
    id 'com.android.application'
    id 'org.jetbrains.kotlin.android'
    id 'com.google.devtools.ksp'
}


android {
    namespace 'com.xyl.roomdemo'
    compileSdk 33

    defaultConfig {
        applicationId "com.xyl.roomdemo"
        minSdk 24
        targetSdk 33
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_17
        targetCompatibility JavaVersion.VERSION_17
    }
    kotlinOptions {
        jvmTarget = '17'
    }
}


dependencies {

    implementation 'androidx.core:core-ktx:1.10.1'
    implementation 'androidx.appcompat:appcompat:1.6.1'
    implementation 'com.google.android.material:material:1.9.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
    testImplementation 'junit:junit:4.13.2'
    androidTestImplementation 'androidx.test.ext:junit:1.1.5'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'

    def room_version = "2.5.0"

    implementation "androidx.room:room-runtime:$room_version"
    annotationProcessor "androidx.room:room-compiler:$room_version"

    // To use Kotlin Symbol Processing (KSP)
    ksp "androidx.room:room-compiler:$room_version"


    // optional - Test helpers
    testImplementation "androidx.room:room-testing:$room_version"



}

使用

创建数据库抽象类

AppDataBase.kt

@Database(entities = [User::class], version = 1)
abstract class AppDatabase : RoomDatabase(){
    abstract fun userDao(): UserDao
}

创建entity类

User.kt

@Entity
data class User (
    @PrimaryKey val uid: Int,
    @ColumnInfo(name = "name") val name: String?,
    @ColumnInfo(name = "sex") val sex: String?
)

创建Dao类

package com.xyl.roomdemo.dao

import androidx.room.Dao
import androidx.room.Delete
import androidx.room.Insert
import androidx.room.Query
import androidx.room.Update
import com.xyl.roomdemo.entity.User

@Dao
interface UserDao {
    @Query("select * from user")
    fun getAll(): List<User>
    @Query("select * from user where uid = (:queryId)")
    fun getUserById(queryId: Int): User
    @Insert
    fun addUser(user: User)
    @Update
    fun updateUser(user: User)
    @Delete
    fun delUser(user: User)

}

配置数据库

App.kt

class App: Application() {
    lateinit var db: AppDatabase
    override fun onCreate() {
        super.onCreate()
        Log.i(TAG, "onCreate: app启动")
        GlobalScope.launch(Dispatchers.IO) {
            db = Room.databaseBuilder(applicationContext, AppDatabase::class.java, "database-name")
                .build()
        }
    }
}

使用示例

MainActivity.kt

package com.xyl.roomdemo

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import com.xyl.roomdemo.entity.User
import com.xyl.roomdemo.utils.TAG
import kotlinx.coroutines.DelicateCoroutinesApi
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.GlobalScope
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val app: App = application as App

        GlobalScope.launch(Dispatchers.IO) {
            val dao = app.db.userDao()
            dao.addUser(User(1001, "小明", "男"))
            dao.addUser(User(1002, "小红", "女"))
            dao.addUser(User(1003, "小花", "女"))
            dao.addUser(User(1004, "张三", "男"))
            dao.delUser(User(1002, "", ""))
            val userList = dao.getAll()
            withContext(Dispatchers.Main) {
                Log.i(TAG, "onCreate: ${userList.toString()}")
            }

        }

    }
}

参考文档

https://developer.android.com/training/data-storage/room?hl=zh-cn#setup