简介

实现一个通用排序工具类，根据用户所选择的排序对象进行排序；例如通过年龄排序、通过工资排序、或者工资相等的情况下使用年龄排序

代码实现

代码结构图：

 

 

package cn.test.logan.day08;

import java.util.ArrayList;

public class SortUtilTest {
    public static void main(String[] args) {
        User u1 = new User("001","张三",30,1000);
        User u2 = new User("002","李四",29,1200);
        User u3 = new User("003","王五",27,1000);
        User u4 = new User("004","狗蛋",24,1400);
        
        ArrayList<User> list = new ArrayList<>();
        list.add(u1);
        list.add(u2);
        list.add(u3);
        list.add(u4);
        
        // 根据年龄排序
        //SortUtil.sort(list, new AgeCompare());
        
        // 根据工资排序
        //SortUtil.sort(list, new SalaryCompare());
        
        //  先根据工资，工资相等则根据年龄
        SortUtil.sort(list, new SalaryAgeCompare());
        
        
        
        for(User u:list) {
            System.out.println(u);
        }
    }
}

SortUtilTest.java

package cn.test.logan.day08;

import java.util.ArrayList;

public class SortUtil {
    public static void sort(ArrayList<User> uList,Compare com) {
        for(int i=0;i<uList.size()-1;i++) {
            for(int j=0;j<uList.size()-1-i;j++) {
                // 判断大小
                boolean res = com.compare(uList.get(j), uList.get(j+1));
                if(res) {
                    User tmp = uList.get(j);
                    uList.set(j,uList.get(j+1));
                    uList.set(j+1, tmp);
                }
            }
        }
    }
}

SortUtil.java

package cn.test.logan.day08;

public interface Compare {
    public boolean compare(User u1,User u2);
}

Compare.java

package cn.test.logan.day08;
/**
 * 定义一个User类
 * 包含：ID,姓名,年龄,薪水
 * @author QIN
 *
 */
public class User {


    private String id;
    private String name;
    private int age;
    private float salary;
    
    public User() {
        
    }
    
    public User(String id, String name, int age, float salary) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.salary = salary;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    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 float getSalary() {
        return salary;
    }

    public void setSalary(float salary) {
        this.salary = salary;
    }
    
    // 定义toString方法
    @Override
    public String toString() {
        return this.id + "," + this.name + "," + this.age + "," + this.salary;
    }
    
    
}

User.java

以下三个分别是对年龄、工资、先工资后年龄排序的类

package cn.test.logan.day08;

public class AgeCompare implements Compare{

    @Override
    public boolean compare(User u1, User u2) {
        if(u1.getAge() > u2.getAge()) {
            return true;
        }
        return false;
    }

}

AgeCompare .java

package cn.test.logan.day08;

public class SalaryCompare implements Compare{
    @Override
    public boolean compare(User u1, User u2) {
        if(u1.getSalary() > u2.getSalary()) {
            return true;
        }
        return false;
    }

}

SalaryCompare.java

 

package cn.test.logan.day08;

public class SalaryAgeCompare implements Compare{

    @Override
    public boolean compare(User u1, User u2) {
        // 先根据工资排序，如果工资相同再根据年龄排序
        if(u1.getSalary() > u2.getSalary()) {
            return true;
        }
        if(u1.getSalary() == u2.getSalary()) {
            if(u1.getAge() > u2.getAge() ) {
                return true;
            }
        }
        return false;
        
    }

}

SalaryAgeCompare.java