package com.atguigu.java8; import java.util.ArrayList; import java.util.Arrays; import java.util.Comparator; import java.util.List; import java.util.TreeSet; import org.junit.Test; public class TestLambda1 { //原来的匿名内部类 @Test public void test1(){ Comparator<String> com = new Comparator<String>(){ @Override public int compare(String o1, String o2) { return Integer.compare(o1.length(), o2.length()); } }; TreeSet<String> ts = new TreeSet<>(com); TreeSet<String> ts2 = new TreeSet<>(new Comparator<String>(){ @Override public int compare(String o1, String o2) { return Integer.compare(o1.length(), o2.length()); } }); } //现在的 Lambda 表达式 @Test public void test2(){ Comparator<String> com = (x, y) -> Integer.compare(x.length(), y.length()); TreeSet<String> ts = new TreeSet<>(com); } }