首页 文章

当参数从泛型函数被覆盖时,将泛型参数clazz放到RealmQuery中

提问于
浏览
1

实际上我正在用Kotlin为Android Studio项目编写一个存储库模式 . 我有一个名为“BaseRepository”的通用接口 . 此接口从“BaseRealmRepository”和其他接口扩展而来 .

我需要将Realm.db的所有结果都放到findAll()中,但是我无法修改这个继承的函数,因为它在其他存储库中是通用的 .

当我尝试时,我收到以下错误:

"fun findAllRealm ( clazz: Class ) : List is not satisfied: inferred type GenericRealmModelType<> is not a subtype of RealmModel"*

但我真正的问题是 clazz parameter of ClassI need do cast or something 传递给"where"的realmQuery without modify the generic function adding upper bounds like or similar

这是我的通用界面:

interface BaseRepository<T> {

fun create(item: T) : T

fun remove(item: T)

fun update(item: T) : T

fun find(item: T): T

fun <T> findAll(clazz: Class<T>): List<T>

}

我为do cast创建了一个泛型类型:

interface GenericRealmModelType<out T: RealmModel>{}

最后,我从“BaseRepository”扩展的抽象类“BaseObjectsRealmRepository”:

abstract class BaseObjectsRealmRepository<T> : BaseRepository<T> {

...

override fun <T> findAll(clazz:  Class<T>): List<T> {


     var klazz: Class<GenericRealmModelType<*>>  = clazz as Class<GenericRealmModelType<*>>

     val allResults =  findAllRealm(klazz)

     return allResults

}


private fun <T: RealmModel> findAllRealm(clazz: Class<T>): List<T>{

    val realm = Realm.getDefaultInstance()

    val realmResults = realm
            .where(clazz) //CLAZZ IS MY PROBLEM
            .findAll()

    val allResults: List<T> = realm.copyFromRealm(realmResults)

    return allResults
}
}

项目配置如下:

项目build.gradle:

buildscript {
ext.kotlin_version = '1.2.41'
repositories {
    google()
    jcenter()
}
dependencies {
    classpath 'com.android.tools.build:gradle:3.1.2'
    classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    classpath "io.realm:realm-gradle-plugin:5.1.0"
    classpath 'com.google.gms:google-services:3.2.0'
    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
}
}

allprojects {
repositories {
    google()
    jcenter()
    maven {
        url "https://maven.google.com"
    }
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}

模块应用build.gradle:

apply plugin: 'com.android.application'

apply plugin: 'kotlin-android'

apply plugin: 'kotlin-android-extensions'

apply plugin: 'kotlin-kapt'

apply plugin: 'realm-android'

android {
compileSdkVersion 27
defaultConfig {
    applicationId "com.example.example"
    minSdkVersion 16
    targetSdkVersion 27
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner 
"android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 
'proguard-rules.pro'
    }
}
}

dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation"org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
implementation 'com.android.support:appcompat-v7:27.1.1'
implementation 'com.android.support.constraint:constraint-layout:1.1.0'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso- 
core:3.0.2'


implementation 'com.google.dagger:dagger-android:2.12'
implementation 'com.google.dagger:dagger-android-support:2.12'
kapt 'com.google.dagger:dagger-android-processor:2.12'
kapt 'com.google.dagger:dagger-compiler:2.13'

implementation 'com.android.support:support-annotations:27.1.1'

implementation 'com.google.firebase:firebase-auth:15.1.0'
implementation 'com.google.android.gms:play-services-auth:15.0.1'
implementation 'com.google.firebase:firebase-core:15.0.2'
implementation 'com.android.support:support-v4:27.1.1'
implementation 'com.android.support:recyclerview-v7:27.1.1'
implementation 'com.android.support:design:27.1.1'
}

realm {
syncEnabled = true
}

repositories {
mavenCentral()
}





// Add to the bottom of the file
apply plugin: 'com.google.gms.google-services'

我能做什么?

谢谢!

2 回答

  • 0

    我相信你可以通过完全删除_2490121来解决这个问题 .

    abstract class BaseObjectsRealmRepository<T> : BaseRepository<T> {
    
    ...
    
        override fun <T> findAll(clazz: Class<T>): List<T> =
            Realm.getDefaultInstance().use { r ->
                r.copyFromRealm(r.where(clazz).findAll())
            }
    
  • 0

    我得到了解决方案:

    BaseObjectsrealmRepository:

    改变这个:

    旧:抽象类BaseObjectsRealmRepository:BaseRepository {

    新增功能:抽象类BaseObjectsRealmRepository构造函数(clazz:Class):BaseRepository {

    现在下一个代码:

    override fun findAll(clazz:  Class<T>): List<T> {
    
         val allResults =  findAllRealm(clazz)
    
         return allResults
    
    }
    
    
    private fun findAllRealm(clazz: Class<T>): List<T>{
    
    
        val realm = Realm.getDefaultInstance()
    
        val realmResults = realm
                .where(clazz)
                .findAll()
    
        val allResults: List<T> = realm.copyFromRealm(realmResults)
    
        return allResults
     }
    

    谢谢!

相关问题