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方法引用

静态方法引用

实例方法引用

特定类型的方法引用

代码

代码一：静态方法引用+实例方法引用

Test类（里面的Student类见前面Arrays的代码-学生类）

package com.itheima.method_reference;import com.itheima.Arrays.Student;import java.util.Arrays;
import java.util.Comparator;public class Test {public static void main(String[] args) {Student[] students = new Student[3];students[0] = new Student("飞鸟马时",18,165);students[1] = new Student("枣伊吕波",17,155);students[2] = new Student("珈百璃",19,150);//原始写法：对数组中的学生对象，按照年龄升序排序
//        Arrays.sort(students, new Comparator<Student>() {
//            @Override
//            public int compare(Student o1, Student o2) {
//                return o1.getAge() - o2.getAge();//按年龄升序排序
//            }
//        });//使用Lambda简化后的形式//Arrays.sort(students,(o1,o2)->o1.getAge() - o2.getAge());//Arrays.sort(students,(o1, o2) -> CompareByData.compareByAge(o1 ,o2));//静态方法引用//Arrays.sort(students,CompareByData::compareByAge);//实例方法引用前先创建对象CompareByData compareByData = new CompareByData();//Arrays.sort(students,((o1, o2) -> compareByData.compareByAgeDsc(o1,o2)));//实例方法引用Arrays.sort(students,compareByData::compareByAgeDsc);System.out.println(Arrays.toString(students));}
}

代码二：特定类型的方法引用

package com.itheima.method_reference;import java.util.Arrays;
import java.util.Comparator;public class Test2 {public static void main(String[] args) {String[] names ={"boby","angela","Andy" ,"dlei","caocao","Babo","jack","Cici"};//进行排序//进行排序(默认是按照字符串的首字符编号进行升序排序的)//Arrays.sort(names);//System.out.println(Arrays.toString(names));//要求忽略首字符大小写进行排序。
//        Arrays.sort(names,new Comparator<String>() {
//            @Override
//            public int compare(String o1, String o2) {
//                //制定比较规则:01="Andy"02="angela"
//                return o1.compareToIgnoreCase(o2);
//            }
//        });//上述代码使用Lambda简化//Arrays.sort(names,(String o1, String o2) ->o1.compareToIgnoreCase(o2));//特定类型的方法引用!Arrays.sort(names, String::compareToIgnoreCase);System.out.println(Arrays.toString(names));}
}

代码三：构造器引用（理解语法即可）

Car类

package com.itheima.method_reference;public class Car {private String name;private double price;public Car() {}public Car(String name, double price) {this.name = name;this.price = price;}public String getName() {return name;}public void setName(String name) {this.name = name;}public double getPrice() {return price;}public void setPrice(double price) {this.price = price;}@Overridepublic String toString() {return "Car{" +"name='" + name + '\'' +", price=" + price +'}';}
}

Test类(主程序)

package com.itheima.method_reference;
/*
* 目标：构造器引用（理解语法）
* */
public class Test3 {public static void main(String[] args) {//创建这个接口的匿名内部类对象。
//        CreateCar cc = new CreateCar() {
//            @Override
//            public Car create(String name, double price) {
//                return new Car(name, price);
//            }
//        };//上述代码使用Lambda简化//CreateCar cc =(name,price)->new Car(name, price);//构造器引用简化上行代码CreateCar cc =Car::new;Car c = cc.create("奔驰", 49.9);System.out.println(c);}
}
interface CreateCar{Car create(String name,double price);
}