Lamda java8- reference from a reference to a method and structure

A method references Overview

After the previous chapter 2 Lamda Lamda and analytical principles introduced, it will basically familiar with Lamda expression, this time we are more in-depth point. Take a look at reference method.
Method is a shorthand reference to specific Lamda expressions , the idea is that we can replace the Lamda expression directly call the function using the method name.
The syntax is: class name :: method name.

Two three methods cited

1 reference point static method

Syntax: static class name (ClassName) :: method name (MethodName)
Example:

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

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

2 a reference to an object example of a method

Syntax: Example Name (instanceName) :: method name (MethodName)
external parameters into the non-target object refers to
an example:

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

Examples of method reference point 3

Syntax: object name (ClassName) :: name Method (Method)
object refers to an object reference into the

    //3 Lamda表达式
    @Test
    public void InstanceMethodLamdaTest(){
        Car car = new Car("100", "black", "中国", 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", "中国", 20);
        Function<Car,String> function = Car::getColor;
        System.out.println(function.apply(car));//black
    }

Three constructors quote

Syntax: object name (ClassName) :: new

    @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);
    }

Four micro-channel public number

I feel good writing can focus the next micro-channel public number, more systematic study, we enter the next phase of Stream flow.