调用需要 API 级别 24 java.util.comparator

Question

使用 Comparator 时出现 api 级别错误，但是当我添加 @RequiresApi(N) 注释时，错误得到解决。

问题是添加 @RequiresApi(N) 注释后，此应用程序无法在低于 24 的 api 级别运行，我在 API 23 手机上收到此错误 -

 Process: com.example.chatapp, PID: 13778
java.lang.NoClassDefFoundError: adapters.chatPageAdapter$$ExternalSyntheticLambda0
    at adapters.chatPageAdapter.onBindViewHolder(chatPageAdapter.java:59)
    at adapters.chatPageAdapter.onBindViewHolder(chatPageAdapter.java:25)
    at androidx.recyclerview.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:7065)
    at androidx.recyclerview.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:7107)
    at androidx.recyclerview.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:6012)
    at androidx.recyclerview.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:6279)
    at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:6118)
    at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:6114)
    at androidx.recyclerview.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2303)
    at androidx.recyclerview.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1627)
    at androidx.recyclerview.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1587)
    at androidx.recyclerview.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:665)
    at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:4134)
    at androidx.recyclerview.widget.RecyclerView.onMeasure(RecyclerView.java:3540)

那么，有什么方法可以使用这个方法，甚至可以在 23 以下的 api 上运行应用程序吗？

构建.Gradle -

android {
    compileSdk 30

buildFeatures {
    viewBinding true
}

defaultConfig {
    applicationId "com.example.chatapp"
    minSdk 23
    targetSdk 30
    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_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}
}

Answer 1

您可以启用脱糖- 它将允许较低的 api 版本也使用最新的 java8 功能。

在您的应用程序模块中build.gradle，添加coreLibraryDesugaringEnabled

 compileOptions {
        // Flag to enable support for the new language APIs
        coreLibraryDesugaringEnabled true
        // Sets Java compatibility to Java 8
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

dependencies {
    coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.1.5'
}