Jjava8 Lambda 神操作

  1 public class lambda {
  2 
  3     @functionalinterface
  4     public interface addinter {
  5         void add(int x, long y);
  6     }
  7 
  8     public interface addintertow extends addinter {
  9         void add(int x, long y);
 10     }
 11 
 12     ///predicate 传入apple类型的参数
 13     private static list<apple> findapple1(list<apple> applelist, predicate<apple> applepredicate) {
 14         arraylist<apple> newarraylist = lists.newarraylist();
 15         for (apple apple : applelist) {
 16             if (applepredicate.test(apple)) {
 17                 newarraylist.add(apple);
 18             }
 19         }
 20         return newarraylist;
 21     }
 22 
 23     ///predicate 传入long类型的参数 一个参数调用括号可以省略
 24     private static list<apple> findapple2(list<apple> applelist, predicate<long> applepredicate) {
 25         arraylist<apple> newarraylist = lists.newarraylist();
 26         for (apple apple : applelist) {
 27             if (applepredicate.test(apple.getweight())) {
 28                 newarraylist.add(apple);
 29             }
 30         }
 31         return newarraylist;
 32     }
 33 
 34     ///两个参数的
 35     private static list<apple> findapple3(list<apple> applelist, bipredicate<string, long> applepredicate) {
 36         arraylist<apple> newarraylist = lists.newarraylist();
 37         for (apple apple : applelist) {
 38             if (applepredicate.test(apple.getcolor(), apple.getweight())) {
 39                 newarraylist.add(apple);
 40             }
 41         }
 42         return newarraylist;
 43     }
 44 
 45     ///一个参数的consumer,accept方法没有返回值 具体干什么你来定
 46     private static void findapple4(list<apple> applelist, consumer<apple> appleconsumer) {
 47         for (apple apple : applelist) {
 48             appleconsumer.accept(apple);
 49         }
 50     }
 51     ///两个参数的
 52     private static void findapple5(string d,list<apple> applelist, biconsumer<apple,string> appleconsumer) {
 53         for (apple apple : applelist) {
 54             appleconsumer.accept(apple,d);
 55         }
 56     }
 57     private static string findapple6(apple apple, function<apple,string> stringfunction) {
 58        return  stringfunction.apply(apple);
 59     }
 60 
 61     public static void main(string[] args) {
 62         arraylist<apple> list = lists.newarraylist(new apple("gree", 150l), new apple("red", 200l), new apple("blue", 300l));
 63         ///predicate一个参数 || bipredicate两个参数 || intpredicate int参数的
 64         list<apple> apple1 = findapple1(list, (apple) -> apple.getcolor().equals("red"));
 65         system.out.println(json.tojsonstring(apple1));
 66         list<apple> apple2 = findapple2(list, num -> num > 150l);
 67         system.out.println(json.tojsonstring(apple2));
 68         list<apple> apple3 = findapple3(list, (a, b) -> a.equals("red") && b >= 200);
 69         system.out.println(apple3);
 70         system.out.println("==========================================>");
 71 
 72         ///consumer 一个参数的
 73         findapple4(list, a -> system.out.println("{"+a.getcolor()+":"+a.getweight()+"}"));
 74         findapple5("consumer",list,(a,b)-> system.out.println(a.getcolor()+":"+a.getweight()+":"+b));
 75         system.out.println("=======================================>");
 76         ///function 传入一个值 返回一个值
 77         string apple6 = findapple6(new apple("apple", 3000l), (x) -> x.tostring());
 78         system.out.println(apple6);
 79 
 80         intfunction<double> apple7 = i->i*20.0d;
 81         system.out.println(apple7.apply(20));
 82         //predicate || function ||supplier  || consumer 常用的几个类
 83 
 84         system.out.println("===================================>推导==================");
 85         consumer<string> consumerstring = (s -> system.out.println(s));
 86         consumer(consumerstring,"坚持");
 87         consumer(s-> system.out.println(s),"hellword consunmer");
 88         consumer(system.out::println,"system.out.pring");
 89 
 90         integer aaa = integer.parseint("12345");
 91 
 92 
 93         sfunction<string, integer> stringintegersfunction = integer::parseint;
 94         integer integer = stringintegersfunction.apply("1234");
 95         system.out.println(integer);
 96 
 97 
 98         bifunction<string,long,apple> bifunction = apple::new;
 99         apple biapple = bifunction.apply("biapple", 1000l);
100         system.out.println(biapple);
101     }
102 
103     public static <t> void  consumer(consumer<t> consumer,t t){
104         consumer.accept(t);
105         consumer.accept(t);
106     }
107     public static void lambdarun() {
108         sfunction<string, object> stringobjectsfunction = (string s) -> s.length();
109         system.out.println(stringobjectsfunction.apply("大傻大傻大傻大傻"));
110 
111         predicate<apple> applepredicate = (apple -> apple.getcolor().equals("red1"));
112         system.out.println(applepredicate.test(new apple("red", 123l)));
113 
114         supplier<apple> applesupplier = apple::new;
115         system.out.println(applesupplier.get());
116 
117         runnable run = new runnable() {
118             @override
119             public void run() {
120                 system.out.println("hello word");
121             }
122         };
123         runnable runnable = () -> system.out.println("hello word");
124         startrunnable(runnable);
125         startrunnable(run);
126         startrunnable(() -> system.out.println("hello"));
127     }
128 
129     public static void startrunnable(runnable runnable) {
130         runnable.run();
131     }
132 }