将集合内容转化为文件

main

点击查看代码

package it_05;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Comparator;
import java.util.TreeSet;

public class Demo6 {
    public static void main(String[] args)throws IOException {
        TreeSet<Student> treeSet = new TreeSet<>(new Comparator<Student>() {
            @Override
            public int compare(Student o1, Student o2) {
                int sum2= o2.getChinese()+o2.getEnglish()+o2.getMath();
                int sum1=o1.getChinese()+o1.getMath()+o1.getEnglish();
                int num =  sum2- sum1;
                int num2 = num==0? o2.getName().compareTo(o1.getName()):num;
                return  num2;
            }
        });
        Student s1 =new Student("kkk",23,56,62);
        Student s2 = new Student("lll",56,49,88);
        Student s3 = new Student("nnn",50,41,84);
        treeSet.add(s1);
        treeSet.add(s2);
        treeSet.add(s3);
        BufferedWriter bw =new BufferedWriter(new FileWriter("student2"));
        for (Student student : treeSet) {
            StringBuilder sb =new StringBuilder();
            StringBuilder s = sb.append(student.getName()).append(",").append(student.getChinese()).append(",").append(student.getMath()).append(",").append(student.getEnglish());
            String ss = s.toString();
            bw.write(ss);
            bw.newLine();
            bw.flush();
        }
        bw.close();

    }
}

syudent

点击查看代码

package it_05;

public class Student {
    private String name;
    private int chinese;
    private int math;
    private int english;

    public Student(){}

    public Student(String name,int chinese,int math,int english){
        this.name=name;
        this.chinese=chinese;
        this.math=math;
        this.english=english;
    }

    public String getName() {
        return name;
    }

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

    public int getChinese() {
        return chinese;
    }

    public void setChinese(int chinese) {
        this.chinese = chinese;
    }

    public int getMath() {
        return math;
    }

    public void setMath(int math) {
        this.math = math;
    }

    public int getEnglish() {
        return english;
    }

    public void setEnglish(int english) {
        this.english = english;
    }
}