方法引用 类调用非静态方法的示例

实例Bean
package com.atguigu.cachestudy.bean;

import lombok.Data;

@Data
public class Emplyer {
    private int id;
    private String name;
    private double salary;
    private int age;

    public Emplyer() {
        super();
    }

    public Emplyer(int id, String name) {
        this.id = id;
        this.name = name;
    }

    public Emplyer(int id) {
        this.id = id;
        System.out.println( "Emplyer(int id)" );
    }

    public Emplyer(int id, String name, double salary, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.salary = salary;

    }

    public void testEmplyer() {
        System.out.println( "hello world!!!!" );
    }
}

测试代码

package function;

import com.atguigu.cachestudy.bean.Emplyer;
import org.junit.jupiter.api.Test;

import java.util.Arrays;
import java.util.Comparator;
import java.util.function.*;

public class Function003 {
    @Test
    public void test001() {
        Comparator<String> comparator = (s1, s2) -> s1.compareTo( s2 );
        System.out.println( comparator.compare( "ab", "abd" ) );
        System.out.println( "*****************" );
        Comparator<String> comparator2 = String::compareTo;
        System.out.println( comparator2.compare( "ab", "abc" ) );
    }

    @Test
    public void test002() {
        BiPredicate<String, String> biPredicate1 = (s1, s2) -> s1.equals( s2 );
        System.out.println( biPredicate1.test( "abc", "abc" ) );
        System.out.println( "************************" );
        BiPredicate<String, String> biPredicate2 = String::equals;
        System.out.println( biPredicate2.test( "abc", "abd" ) );
    }

    @Test
    public void test003() {
        Emplyer em = new Emplyer( 2, "zhangsan", 11000.5, 30 );
        Function<Emplyer, String> fuc = e -> e.getName();
        System.out.println( fuc.apply( em ) );
        System.out.println( "***********************************" );
        Function<Emplyer, String> fuc2 = Emplyer::getName;
        System.out.println( fuc2.apply( em ) );
    }

    @Test
    public void test004() {
        Emplyer em = new Emplyer( 2, "zhangsan", 11000.5, 30 );
        Consumer<Emplyer> con = e -> e.testEmplyer();
        con.accept( em );
        System.out.println( "*********************" );
        Consumer<Emplyer> con1 = Emplyer::testEmplyer;
        con1.accept( em );
    }

    //    无参构造器引用示例
    @Test
    public void test005() {
        Supplier<Emplyer> supplier = () -> new Emplyer();
        System.out.println( supplier.get() );
        System.out.println( "***************************" );
        Supplier<Emplyer> supplier1 = Emplyer::new;
        System.out.println( supplier1.get() );
    }

    //    有参构造器引用示例
    @Test
    public void test006() {
        Function<Integer, Emplyer> func = (id) -> new Emplyer( id );
        Emplyer emplyer = func.apply( 1001 );
        System.out.println( emplyer );
        System.out.println( "*******************" );
        Function<Integer, Emplyer> func1 = Emplyer::new;
        Emplyer emplyer1 = func1.apply( 1002 );
        System.out.println( emplyer1 );
        System.out.println( "*******************" );
        BiFunction<Integer, String, Emplyer> func2 = Emplyer::new;
        Emplyer emplyer2 = func2.apply( 1003, "张三" );
        System.out.println( emplyer2 );
    }
/**
 * 数组引用示例
 */
    @Test
    public void test007() {
        Function<Integer, String[]> fun = (id) -> new String[id];
        String[] str = fun.apply( 5 );
        System.out.println( Arrays.toString( str ) );
        System.out.println( "**********************" );
        Function<Integer, String[]> fun1 = String[]::new;
        String[] str1 = fun1.apply( 5 );
        System.out.println( Arrays.toString( str1 ) );
    }


}