JAVA 基础编程练习题50 【程序 50 文件 IO】

50 【程序 50 文件 IO】

题目：有五个学生，每个学生有 3 门课的成绩，从键盘输入以上数据（包括学生号，姓名，三门课成绩）， 计算出平均成绩，将原有的数据和计算出的平均分数存放在磁盘文件"stud"中。

package cskaoyan;

import java.io.BufferedWriter;

import java.io.File;

import java.io.FileWriter;

import java.io.IOException;

class Student {

	private String id;

	private String name;

	private double math;

	private double english;

	private double c;

	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 double getMath() {

		return math;

	}

	public void setMath(double math) {

		this.math = math;

	}

	public double getEnglish() {

		return english;

	}

	public void setEnglish(double english) {

		this.english = english;

	}

	public double getC() {

		return c;

	}

	public void setC(double c) {

		this.c = c;

	}

	public double getAverage() {

		return (this.math + this.english + this.c) / 3;

	}

}

public class cskaoyan50 {

	public static void main(String[] args) {

		// TODO Auto-generated method stub

		java.util.Scanner in = new java.util.Scanner(System.in);

		Student student1 = new Student();

		Student student2 = new Student();

		Student student3 = new Student();

		Student student4 = new Student();

		Student student5 = new Student();

		System.out.println("请输入5个同学的信息：学生号，姓名，3门成绩:");

		System.out.print("学号:");

		student1.setId(in.next());

		System.out.print("姓名:");

		student1.setName(in.next());

		System.out.print("第" + 1 + "门课成绩:");

		student1.setMath(in.nextDouble());

		System.out.print("第" + 2 + "门课成绩:");

		student1.setEnglish(in.nextDouble());

		System.out.print("第" + 3 + "门课成绩:");

		student1.setC(in.nextDouble());

		System.out.print("学号:");

		student2.setId(in.next());

		System.out.print("姓名:");

		student2.setName(in.next());

		System.out.print("第" + 1 + "门课成绩:");

		student2.setMath(in.nextDouble());

		System.out.print("第" + 2 + "门课成绩:");

		student2.setEnglish(in.nextDouble());

		System.out.print("第" + 3 + "门课成绩:");

		student2.setC(in.nextDouble());

		System.out.print("学号:");

		student3.setId(in.next());

		System.out.print("姓名:");

		student3.setName(in.next());

		System.out.print("第" + 1 + "门课成绩:");

		student3.setMath(in.nextDouble());

		System.out.print("第" + 2 + "门课成绩:");

		student3.setEnglish(in.nextDouble());

		System.out.print("第" + 3 + "门课成绩:");

		student3.setC(in.nextDouble());

		System.out.print("学号:");

		student4.setId(in.next());

		System.out.print("姓名:");

		student4.setName(in.next());

		System.out.print("第" + 1 + "门课成绩:");

		student4.setMath(in.nextDouble());

		System.out.print("第" + 2 + "门课成绩:");

		student4.setEnglish(in.nextDouble());

		System.out.print("第" + 3 + "门课成绩:");

		student4.setC(in.nextDouble());

		System.out.print("学号:");

		student5.setId(in.next());

		System.out.print("姓名:");

		student5.setName(in.next());

		System.out.print("第" + 1 + "门课成绩:");

		student5.setMath(in.nextDouble());

		System.out.print("第" + 2 + "门课成绩:");

		student5.setEnglish(in.nextDouble());

		System.out.print("第" + 3 + "门课成绩:");

		student5.setC(in.nextDouble());

		BufferedWriter bw = null;

		try {

			FileWriter fw = new FileWriter(new File("d://student.txt"));

			bw = new BufferedWriter(fw);

			bw.write("学号:" + student1.getId() + "  ");

			bw.write("姓名:" + student1.getName() + "  ");

			bw.write("成绩:{  ");

			bw.write(student1.getMath() + "  " + student1.getEnglish() + "  " + student1.getC() + "  ");

			bw.write("} ");

			bw.write("平均成绩: " + student1.getAverage());

			bw.newLine();

			bw.write("学号:" + student2.getId() + "  ");

			bw.write("姓名:" + student2.getName() + "  ");

			bw.write("成绩:{  ");

			bw.write(student2.getMath() + "  " + student2.getEnglish() + "  " + student2.getC() + "  ");

			bw.write("} ");

			bw.write("平均成绩: " + student2.getAverage());

			bw.newLine();

			bw.write("学号:" + student3.getId() + "  ");

			bw.write("姓名:" + student3.getName() + "  ");

			bw.write("成绩:{  ");

			bw.write(student3.getMath() + "  " + student3.getEnglish() + "  " + student3.getC() + "  ");

			bw.write("} ");

			bw.write("平均成绩: " + student3.getAverage());

			bw.newLine();

			bw.write("学号:" + student4.getId() + "  ");

			bw.write("姓名:" + student4.getName() + "  ");

			bw.write("成绩:{  ");

			bw.write(student4.getMath() + "  " + student4.getEnglish() + "  " + student4.getC() + "  ");

			bw.write("} ");

			bw.write("平均成绩: " + student4.getAverage());

			bw.newLine();

			bw.write("学号:" + student1.getId() + "  ");

			bw.write("姓名:" + student1.getName() + "  ");

			bw.write("成绩:{  ");

			bw.write(student1.getMath() + "  " + student1.getEnglish() + "  " + student1.getC() + "  ");

			bw.write("} ");

			bw.write("平均成绩: " + student1.getAverage());

			bw.newLine();

			bw.write("学号:" + student5.getId() + "  ");

			bw.write("姓名:" + student5.getName() + "  ");

			bw.write("成绩:{  ");

			bw.write(student5.getMath() + "  " + student5.getEnglish() + "  " + student5.getC() + "  ");

			bw.write("} ");

			bw.write("平均成绩: " + student5.getAverage());

			bw.newLine();

		} catch (IOException e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		} finally {

			try {

				bw.close();

			} catch (IOException e) {

				// TODO Auto-generated catch block

				e.printStackTrace();

			}

		}

		in.close();

	}

}