ClassCastException：我调用改造时Bootstrap方法返回null-Android

Question

我一直在观看有关Android REST API调用的教程，我正在尝试使用Retrofit，但是我的应用程序一直崩溃，我也不知道为什么。

java.lang.BootstrapMethodError: Exception from call site #4 bootstrap method
    at okhttp3.internal.Util.<clinit>(Util.java:87)
    at okhttp3.internal.Util.skipLeadingAsciiWhitespace(Util.java:321)
    at okhttp3.HttpUrl$Builder.parse(HttpUrl.java:1313)
    at okhttp3.HttpUrl.get(HttpUrl.java:917)
    at retrofit2.Retrofit$Builder.baseUrl(Retrofit.java:492)
    at com.example.reinventa.RetrofitClient.<init>(RetrofitClient.java:17)
    at com.example.reinventa.RetrofitClient.getInstance(RetrofitClient.java:24)
    at com.example.reinventa.MainActivity.apiCall(MainActivity.java:128)
    at com.example.reinventa.MainActivity.onCreate(MainActivity.java:54)
    at android.app.Activity.performCreate(Activity.java:7136)
    at android.app.Activity.performCreate(Activity.java:7127)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1271)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2893)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)
    at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
    at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:193)
    at android.app.ActivityThread.main(ActivityThread.java:6669)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
 Caused by: java.lang.ClassCastException: Bootstrap method returned null

感谢您的帮助。