Java基础---学生成绩操作系统

public class Scores {

	private int times;
	
	private String name;
	
	private int score;
	
	private String[] names = new String[]{"张三", "李四", "王五", "薛六", "赵七"};

	public String[] getNames() {
		return names;
	}
	
	public int getTimes() {
		return times;
	}

	public void setTimes(int times) {
		this.times = times;
	}

	public String getName() {
		return name;
	}

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

	public int getScore() {
		return score;
	}

	public void setScore(int score) {
		this.score = score;
	}
	
}

import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map.Entry;
import java.util.Scanner;
import java.util.Set;
import java.util.TreeMap;

public class ScoresService{
	
	Scores stuScores = new Scores();
	Scanner scanner = new Scanner(System.in);
	
	
	//格式输出学生的姓名和成绩
	public void output(LinkedList> lScores){
		System.out.println("+---------------+-----------------------+-----------------------+-----------------------+-----------------------+");
		System.out.println("|\t姓名\t|" + "\t第一次考试成绩\t|"+"\t第二次考试成绩\t|"+"\t第三次考试成绩\t|"+"\t第四次考试成绩\t|");
		System.out.println("+---------------+-----------------------+-----------------------+-----------------------+-----------------------+");
		for(int i = 0 ; i < stuScores.getNames().length ; i ++){
			System.out.println("|\t" + stuScores.getNames()[i] + "\t|\t" + lScores.get(0).get(stuScores.getNames()[i]) + "\t\t|\t" +
								lScores.get(1).get(stuScores.getNames()[i]) + "\t\t|\t" +lScores.get(2).get(stuScores.getNames()[i])
								+ "\t\t|\t" +lScores.get(3).get(stuScores.getNames()[i]) + "\t\t|");
			System.out.println("+---------------+-----------------------+-----------------------+-----------------------+-----------------------+");
		}
	}
	
	
	//查询某次考试的总成绩
	public void queryExamSum(LinkedList> lScores){
		
		int sum = 0;
		
		System.out.println("请输入考试次序：");
		int time = scanner.nextInt();
		
		for(int i = 0 ; i < stuScores.getNames().length ;  i ++){
			sum += lScores.get(time - 1).get(stuScores.getNames()[i]);
		}
		
		System.out.println("第" + time + "次考试的总分为：" + sum);
	}
	
	
	//查询某位考生四次考试的总成绩
	public void queryStudentSum(LinkedList> lScores){
		
		int sum = 0;
		
		System.out.println("请输入学生姓名：");
		String name = scanner.next();
		
		for(int i = 0 ; i < lScores.size() ;  i ++){
			sum += lScores.get(i).get(name);
		}
		
		System.out.println(name + "四次考试的总分为：" + sum);
	}
	
	
	//查询某位考生的平均分
	public void queryStudentAverageScore(LinkedList> lScores){
		
		int sum = 0;
		
		System.out.println("请输入学生姓名：");
		String name = scanner.next();
		
		for(int i = 0 ; i < lScores.size() ;  i ++){
			sum += lScores.get(i).get(name);
		}
		
		int avg = sum / lScores.size();
		System.out.println(name + "四次考试的平均分为：" + avg);
	}
	
	
	//查询历次考试中平均分最高的一次， 并输出该次平均分
	public void queryHighestAverage(LinkedList> lScores){
		
		int sum;
		double maxAvg = 0;
		int time = 0;
		for(int i = 0 ; i < lScores.size() ;  i ++){
			
			sum = 0;
			
			for(int j = 0 ; j < stuScores.getNames().length ; j ++){
				sum += lScores.get(i).get(stuScores.getNames()[j]);
			}
			
			double avg = sum / stuScores.getNames().length;
			System.out.println("第" + (i + 1) + "次考试全班的平均分为：" + avg);
			
			if(maxAvg < avg){
				maxAvg = avg;
				time = i + 1;
			}
		}
		
		System.out.println("全班平均分最高的一次考试是第" + time + "次， 该次平均分为：" + maxAvg);
	}
	
	
	//查询某同学的某次考试成绩
	public void queryStudentAndExamSum(LinkedList> lScores){
		
		int score = 0;
		
		System.out.println("请输入考试次序：");
		int time = scanner.nextInt();
		
		System.out.println("请输入想要查询的同学的姓名：");
		String name = scanner.next();
		
		score = lScores.get(time - 1).get(name);
		
		System.out.println(name + "同学的第" + time + "次的考试成绩为：" + score);
	}

	
	//使用TreeMap对学生总成绩进行排名输出
	public void SumSortByTreeMap(LinkedList> lScores){
	
		HashMap stuSum = new HashMap();
		
		int sum = 0;
		for(int i = 0 ; i < stuScores.getNames().length ;  i ++){
			
			sum = 0;
			
			for(int j = 0 ; j < lScores.size() ; j ++){
				sum += lScores.get(j).get(stuScores.getNames()[i]);
				
				stuSum.put(stuScores.getNames()[i], sum);
			}
			
		}
		
		//将HashMap传入StuSum，使用对value（即历次考试总分）排序的compareTo()方法进行排序
		StuSum tempMap = new StuSum(stuSum);
		
		//将传出的HashMap装入TreeMap
		TreeMap sortedMap = new TreeMap(tempMap);
		sortedMap.putAll(stuSum);
		
		//将TreeMap转化为Entry类，该类具有TreeMap的键(Key)和值(Value) 
		Set> sortedSet = sortedMap.entrySet();
		
		//将Entry装入迭代器，进行遍历输出
		Iterator> iter = sortedSet.iterator();
		while(iter.hasNext()){
			Entry type = (Entry) iter.next();
			String k = type.getKey();
			int v = type.getValue();
			
			System.out.println(k + "<----------->" + v);
		}
		
	}
	
}

import java.util.Comparator;
import java.util.Map;

public class StuSum implements Comparator{

	Map map;
	
	public StuSum(Map map){
		this.map = map;
	}

	@Override
	public int compare(String s1, String s2) {
		// TODO Auto-generated method stub
		if(map.get(s1) >= map.get(s2)){
			return -1;
		}else{
			return 1;
		}
	}
}

import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Scanner;
import java.util.Set;

public class ScoresDemo {
	
	public static void main(String[] args) {
		
		Scores stuScores = new Scores();
		ScoresService ss = new ScoresService();
		
		LinkedList> lScores = new LinkedList>();
		Scanner scanner = new Scanner(System.in);
		
		//以 i 来计考试次数
		for(int i = 0; i < 4; i ++){
			HashMap hScores = new HashMap();
			
			//以 j 来计第几个考生的成绩
			for(int j = 0; j < stuScores.getNames().length; j ++){
				
				System.out.println("请输入" + stuScores.getNames()[j] + "的第" + (i + 1) + "门的成绩：");
				int n = scanner.nextInt();
				hScores.put(stuScores.getNames()[j], n);
			}
			lScores.add(hScores);
		}
		
		//遍历输出
		ss.output(lScores);
		
		ss.queryExamSum(lScores);
		
		ss.queryHighestAverage(lScores);
		
		ss.queryStudentAndExamSum(lScores);
		
		ss.queryStudentAverageScore(lScores);
		
		ss.queryStudentSum(lScores);
		
		ss.SumSortByTreeMap(lScores);
		
	}

}