IO流_键盘录入学生信息按照总分排序并写入文本文件案例

àì夳堔傛蜴生んèń 2022-07-10 11:57 156阅读 0赞

学生类

package cn.itcast_06;
    
    public class Student {
    	// 姓名
    	private String name;
    	// 语文
    	private int chinese;
    	// 数学
    	private int math;
    	// 英语
    	private int english;
    
    	public Student() {
    		super();
    		// TODO Auto-generated constructor stub
    	}
    
    	public Student(String name, int chinese, int math, int english) {
    		super();
    		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;
    	}
    
    	public int getSum() {
    		return this.chinese + this.math + this.english;
    	}
    }

测试类

package cn.itcast_06;
    
    import java.io.BufferedWriter;
    import java.io.FileWriter;
    import java.io.IOException;
    import java.util.Comparator;
    import java.util.Scanner;
    import java.util.TreeSet;
    
    /*
     * 需求:键盘录入5个学生信息(姓名,语文,数学,英语),按照总分从高到低存入文本文件
     * 
     * 分析:
     * 		A:创建学生类
     * 		B:创建集合对象
     * 			TreeSet(Student)
     * 		C:键盘录入学生信息存储到集合
     * 		D:遍历集合,把数据写到文本文件
     */
    public class StudentDemo {
    	public static void main(String[] args) throws IOException {
    		// 创建集合对象
    		TreeSet<Student> ts = new TreeSet<Student>(new Comparator<Student>() {
    			public int compare(Student s1, Student s2) {
    				int num = s2.getSum() - s1.getSum();
    				System.out.println(s2.getSum()+"---"+s1.getSum());
    				int num2 = num == 0 ? s1.getChinese() - s2.getChinese() : num;
    				int num3 = num2 == 0 ? s1.getMath() - s2.getMath() : num2;
    				int num4 = num3 == 0 ? s1.getEnglish() - s2.getEnglish() : num3;
    				int num5 = num4 == 0 ? s1.getName().compareTo(s2.getName())
    						: num4;
    				return num5;
    			};
    		});
    
    		// 键盘录入学生信息存储到集合
    		for (int x = 1; x <= 2; x++) {
    			Scanner sc = new Scanner(System.in);
    			System.out.println("请输入第" + x + "个学生信息");
    			System.out.print("姓名:");
    			String name = sc.nextLine();
    			System.out.print("语文:");
    			int chinese = sc.nextInt();
    			System.out.print("数学:");
    			int math = sc.nextInt();
    			System.out.print("英语:");
    			int english = sc.nextInt();
    
    			Student s = new Student();
    			s.setName(name);
    			s.setChinese(chinese);
    			s.setMath(math);
    			s.setEnglish(english);
    
    			ts.add(s);
    		}
    
    		// 遍历集合,把数据写到文本文件
    		BufferedWriter bw = new BufferedWriter(new FileWriter("students.txt"));
    
    		// 写出数据
    		bw.write("学生信息如下:");
    		bw.newLine();
    		bw.flush();
    		bw.write("姓名,语文成绩,数学成绩,英语成绩");
    		bw.newLine();
    		bw.flush();
    		for (Student s : ts) {
    			StringBuilder sb = new StringBuilder();
    			sb.append(s.getName()).append(",").append(s.getChinese())
    					.append(",").append(s.getMath()).append(",")
    					.append(s.getEnglish());
    
    			bw.write(sb.toString());
    			bw.newLine();
    			bw.flush();
    
    		}
    		bw.close();
    		System.out.println("学生信息存储完毕");
    
    	}
    }