小编vin*_*nt_的帖子

今天遇到了这个问题,花了很多年时间试图重现/弄清楚发生了什么.有人可以解释为什么会发生这种情况,或者这是类型擦除/默认方法/ lambda/polymorphism的错误？取消注释默认方法可以使它运行正常,但我希望它能够按原样运行

输出:

Works fine with an object
Calling consume
Hello
Calling accept with context
Hello
Calling accept via consumer...
Exception in thread "main" java.lang.AbstractMethodError: Method test/LambdaTest$$Lambda$1.accept(Ljava/lang/Object;)V is abstract
    at test.LambdaTest$$Lambda$1/834600351.accept(Unknown Source)
    at test.LambdaTest.main(LambdaTest.java:24)

码

package test;

import java.util.function.Consumer;

public class LambdaTest {

    public static void main(String[] args) {
        Consumer<Context> contextIgnoringObject = new ContextUnawareObject();
        contextIgnoringObject.accept(new Context());

        ContextIgnorer contextIgnoringLambda = () -> {
            System.err.println("Hello");
        };

        System.err.println("Calling consume");
        contextIgnoringLambda.consume();

        System.err.println("Calling accept with context");
        contextIgnoringLambda.accept(new Context());

        Consumer<Context> consumer = contextIgnoringLambda;

        System.err.println("Calling accept via …