Java:java8 lambda retrolambda

文章来自:http://blog.csdn.net/intbird
github:https://github.com/intbird/JAVA8Lambda

import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.Callable;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.function.Supplier;

public class Java8Lambda {


    public static void main(String[] args){
        //1
        new Thread(()-> {System.out.println("hello intbird!");}).start();

        //2
        //JButton button = new JButton("show");
        //button.addActionListener( q -> System.out.print("clickButton") );

        //3
        List list = Arrays.asList("1", "2", "3", "4");
        list.forEach( (n) -> {
            System.out.println(n);
        });

        //4 list规则
        Predicate<List> condition = (n) -> n.size()>2; //>5
        list.stream().filter((x) -> condition.test(list))
               .forEach(name -> System.out.print(name));

        //5 list item规则
        Predicate<String> startWithIndex2 = (n) -> n == "2";
        Predicate<String> lengthThen5 = (str) -> str.length()>0;
        Predicate<String> condition1 = startWithIndex2.and(lengthThen5);
        list.stream()
                .filter(condition1)
              .forEach(name -> System.out.println(name));

        //6 list map修改
        list.stream().map((o)-> o +"_index")
            .forEach(System.out::println);

        //7 list reduce
          String listToString = list.stream().map((o) -> o + "index")
                  .reduce((a,b) -> a + "_\r\n_" + b)  //.reduce(((int a, int b) -> a + b)
                  .get().toString();
          Consumer<String> out = System.out::println;
          out.accept(listToString);

        //1:输入且返回
        Function<String[],String> test = Java8Lambda::method;
        String result = test.apply(new String[]{"hello"," ","intbird"});
        System.out.println(result);

        //2:输入无返回
        Consumer<String> test1 = System.out::println;
        test1.accept("hello intbird!");

        //3:无输入有返回
        Callable<String> test2 = Java8Lambda::method;
        try{
            System.out.println(test2.call());
        }catch (Exception ex){
        }
        Supplier<String> test3 = Java8Lambda::method;
        System.out.println(test3.get());

        //4:检查
        Set<String> set = new HashSet<>();
        set.addAll(Arrays.asList("hello"," ","intbird"));
        Predicate<String> pred = set::contains;
        boolean isHas = pred.test("hello");
        System.out.print(isHas);

    }


    //part 1
    //::
//    一个静态方法（类名：：methname）的一个实例方法
//    特定的对象（instanceref：：methname）一个超棒的方法
//    特定对象（超：：methname）的一个实例方法
//    某一特定类型的任意对象（类名：：methname）一类
//    建设者参考（类名：：新）数组构造函数
//    参考（类型名[ ]：：新）

    //part 2
    private static String method(String...text){
        return text[0]+text[1]+text[2];
    }
    private static String method(){
        return "hello intbird!";
    }
}