什么是Java8Lamda方法引用和構(gòu)造引用

  // 1 Lamda靜態(tài)方法
  @Test
  public void LamdaSTest(){
    String youku1327 = "1327";
    Function function = s -> ObjectUtils.allNotNull(youku1327);
    System.out.println(function.apply(youku1327));// true

  }
  // 靜態(tài)方法引用
  @Test
  public void MethodRefTest(){
    String youku1327 = "youku1327";
    Function function = ObjectUtils::allNotNull;
    System.out.println(function.apply(youku1327));// true
  }

  // 2 Lamda表達式
  @Test
  public void ObjectLamdaTest(){
    Car car = new Car("100", "black", "中國", 20);
    Supplier supplier = ()-> car.getColor();
    System.out.println(supplier.get());//black
  }
  // 對象引用
  @Test
  public void ObjectRefTest(){
    Car car = new Car("100", "black", "中國", 20);
    Supplier<String> supplier = car::getColor;
    System.out.println(supplier.get());//black
  }

  //3 Lamda表達式
  @Test
  public void InstanceMethodLamdaTest(){
    Car car = new Car("100", "black", "中國", 20);
    Function<Car,String> function = s -> s.getColor();
    System.out.println(function.apply(car));//black
  }

  @Test
  public void InstanceMethodRefTest(){
    Car car = new Car("100", "black", "中國", 20);
    Function<Car,String> function = Car::getColor;
    System.out.println(function.apply(car));//black
  }

  @Test
  public void constructLamdaTest(){
    BiFunction<String,Double,Car> biFunction = (s, aDouble) -> new Car(s,aDouble);
    Car car = biFunction.apply("youku1327", 50.0);
    // Car(code=youku1327, color=null, factory=null, price=50.0)
    System.out.println(car);
  }

  @Test
  public void construcMethodRefTest(){
    BiFunction<String,Double,Car> biFunction = Car::new;
    Car car = biFunction.apply("youku1327", 50.0);
    // Car(code=youku1327, color=null, factory=null, price=50.0)
    System.out.println(car);
  }