在Android Studio中的Java 8中使用Lambda

Question

我正在將Java 8與lambda表達式一起使用，並收到此錯誤，我的代碼如下：

Predicate<Site> predicate = c-> c.id == filter.get(0);

並收到以下錯誤：

12-05 10:57:44.745 25416-25416/khabarazma.com E/AndroidRuntime: FATAL EXCEPTION: main
                                                                Process: khabarazma.com, PID: 25416
                                                                java.lang.NoClassDefFoundError: chitva_Pages.-$Lambda$17
                                                                    at chitva_Pages.Search$LoadFilter.lambda$-chitva_Pages_Search$LoadFilter_lambda$20(Search.java:3787)
                                                                    at chitva_Pages.-$Lambda$8.$m$0(Unknown Source)
                                                                    at chitva_Pages.-$Lambda$8.onClick(Unknown Source)
                                                                    at android.view.View.performClick(View.java:4455)
                                                                    at android.view.View$PerformClick.run(View.java:18448)
                                                                    at android.os.Handler.handleCallback(Handler.java:733)
                                                                    at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                    at android.os.Looper.loop(Looper.java:149)
                                                                    at android.app.ActivityThread.main(ActivityThread.java:5064)
                                                                    at java.lang.reflect.Method.invokeNative(Native Method)
                                                                    at java.lang.reflect.Method.invoke(Method.java:515)
                                                                    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:794)
                                                                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:610)
                                                                    at dalvik.system.NativeStart.main(Native Method)

誰能幫我？

Answer 1

您是否已設置本頁上所述的所有必要內容？

您應該為Java8功能配置Gradle：

android {
  ...
  defaultConfig {
    ...
    jackOptions {
      enabled true
    }
  }
  compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
  }
}