JavaSE——工具类

package com.zhao.a02StaticDemo;

public class Student {
    private String name;
    private int age;
    private String gender;


    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public Student(String name, int age, String gender) {
        this.name = name;
        this.age = age;
        this.gender = gender;
    }

    public Student() {
    }

    public void show(){
        System.out.println(name+" "+age+" "+gender);
    }

}

package com.zhao.a02StaticDemo;

import java.util.ArrayList;

//工具类，用于获取集合中最大学生的年龄
public class StudentUtil {
    //工具类中的构造方法要私有化
    private StudentUtil(){}

    public static int getMaxAge(ArrayList<Student> arrayList){
        int maxAge=arrayList.get(0).getAge();
        for (int i = 1; i < arrayList.size(); i++) {
            int thisAge=arrayList.get(i).getAge();
            if (maxAge<thisAge){
                maxAge=thisAge;
            }
        }
        return maxAge;
    }
}

package com.zhao.a02StaticDemo;

import java.util.ArrayList;

public class StudentTest {
    public static void main(String[] args) {
        Student stu1=new Student("张三",18,"男");
        Student stu2=new Student("李四",20,"女");
        Student stu3=new Student("王五",21,"男");

        ArrayList<Student> stuArrayList=new ArrayList<>();
        stuArrayList.add(stu1);
        stuArrayList.add(stu2);
        stuArrayList.add(stu3);

        //使用工具类中的方法获得最大学生的年龄
        int maxAge=StudentUtil.getMaxAge(stuArrayList);
        System.out.println(maxAge);

    }