Java新特性解读JDK8之方法和构造函数引用

package com.example.functionalinterfacedemo;


import java.util.function.BiFunction;
import java.util.function.Function;
import java.util.function.Supplier;


public class MethodRefDemo {
  
  public static void main(String[] args) {
    //静态方法引用
    Function<String, Long> function=Long::parseLong;
    Long apply = function.apply("123");
    System.out.println(apply);
    
    //实例方法引用
    String str=new String("实例方法引用");
    Function<String, Integer> function2=String::length;
    Integer len = function2.apply(str);
    System.out.println(len);
    
    //构造函数:无参
    Supplier<Person> supplier=Person::new;
    Person person = supplier.get();
    System.out.println(person);
    
    //构造函数引用:一个参数
    Function<String, Person> function3=Person::new;
    Person apply2 = function3.apply("jack");
    System.out.println(apply2);
    
    //构造函数引用:两个参数
    BiFunction<Integer, String,Person> biFunction=Person::new;
    Person apply3 = biFunction.apply(12, "tony");
    System.out.println(apply3);
    
    //方法引用作为参数
    test("方法引用作为参数", String::length);
    
  }
  /**
   * 方法引用作为参数
   * @param param 参数 
   * @param function 方法引用
   */ 
  public  static void test(String param,Function<String, Integer> function){
    Integer apply = function.apply(param);
    System.out.println(apply);
  }
}


package com.example.functionalinterfacedemo;


public class Person {
  private Integer age;
  private String name;
  
  public Person() {
    super();
  }
  public Person(Integer age) {
    super();
    this.age = age;
  }
  
  public Person(String name) {
    super();
    this.name = name;
  }
  public Person(Integer age, String name) {
    super();
    this.age = age;
    this.name = name;
  }
  public Integer getAge() {
    return age;
  }
  public void setAge(Integer age) {
    this.age = age;
  }
  public String getName() {
    return name;
  }
  public void setName(String name) {
    this.name = name;
  }
  
  @Override
  public String toString() {
    return "Person [age=" + age + ", name=" + name + "]";
  }
}