java8新特性-foreach&lambda
https://www.cnblogs.com/psyco/p/10593205.html Map<String, Integer> items = new HashMap<>(); items.put("A", 10); items.put("B", 20); items.put("C", 30); items.put("D", 40); items.put("E", 50); items.put("F", 60); items.forEach((k,v)->System.out.println("Item : " + k + " Count : " + v)); items.forEach((k,v)->{ System.out.println("Item : " + k + " Count : " + v); if("E".equals(k)){ System.out.println("Hello E"); } }); List<String> items = new ArrayList<>(); items.add("A"); items.add("B"); items.add("C"); items.add("D"); items.add("E"); // lambda // Output : A,B,C,D,E items.forEach(item -> System