java练习题

 最终代码如下：

package kaoshi;
import java.util.*;
public class Machine{
	//记录学生账号和密码；
	private HashMap<String,String> userB=new HashMap<String,String>();
	{
		userB.put("admin","123");
		userB.put("lisi","456");
		userB.put("张三","oab");
	}
	private HashSet<Question> qb=new HashSet<Question>();
	{
		qb.add(new Question("以下选项哪个不是java基本数据类型？
  A.String	B.char	C.int	D.double","A"));
		qb.add(new Question("以下选项哪个是java基本数据类型？
  A.Int	B.Math	C.Random	D.Date","A"));
		qb.add(new Question("在java中负责对字节代码解释执行的是？
  A.String	B.虚拟机	C.int	D.double","B"));
		qb.add(new Question("一个栈的输入序列为1 2 3 4 5，则下列中不可能是栈的输出序列是？
  A.String	B.char	C.int	D.54132","D"));
		qb.add(new Question("对象的特征在类中表示为变量，成为类的？
  A.String	B.char	C.属性	D.double","C"));
		qb.add(new Question("表达式(11+3*8)/4%3的值是？
  A.String	B.0	C.2	D.double","C"));
		qb.add(new Question("表达式不可以作为循环条件的是？
  A.i++	B.i>5	C.i==2	D.double","A"));
		qb.add(new Question("以下哪个不是合法的标识符？
  A.STRING	B.X3	C.DE$f	D.void","D"));
		qb.add(new Question("下列说法正确的是？
  A. JAVA程序的main方法必须写在类里面	B.X3	C.DE$f	D.void","A"));
		/*
		Iterator<Question> it=qb.iterator();
		while(it.hasNext()){
			System.out.println(it.next());
		}
		*/
	}//利用块初始化HashSet集合内的题目对象；
	public HashMap<String,String> getUserB(){
		return userB;
	}
	public ArrayList<Question> getPaper(){
		
		HashSet<Question> paper=new HashSet<Question>();//试卷
		Random rd=new Random();
		ArrayList<Question> qbb=new ArrayList<Question>(this.qb);
				
		while(paper.size()!=5){//试卷的题目数量；
			int value=rd.nextInt(qb.size());
			paper.add(qbb.get(value));
			
			//System.out.println(paper.size()+" "+value);
		}
		
		
		return new ArrayList<Question>(paper);
	}
	
	public boolean login(String name,String password){
		String realps=this.getUserB().get(name);
		if(realps!=null && realps.equals(password)){
			return true;
		}
		return false;
		/*
		Set<String> names=this.getUserB().keySet();//获取用户名集合；
		Iterator<String> it=names.iterator();		
		boolean rs=false;
		while(it.hasNext()){
			String ii=it.next();
			//System.out.println(ii);
			if(name.equals(ii)){				
				if(password.equals(this.getUserB().get(name))){
					rs=true;									
				}
				break;
			}
		}
		return rs;	
		*/
	}
	
}

　

package kaoshi;
public class Question{
	private String title;//题干
	private String answer;//真实答案；
	public Question(String title,String answer){
		this.title=title;
		this.answer=answer;
	}
	public String getTitle(){
		return title;
	}
	public String getAnswer(){
		return answer;
	}
	//重写方法 比较题干
	public boolean equals(Object obj){
		if(this==obj){
			return true;
		}
		if(obj instanceof Question){
			Question anotherQ=(Question)obj;
			if(this.title.equals(anotherQ.title)){
				return true;
			}
		}
		return false;
	}
	public int hashCode(){
		return this.title.hashCode();
	}
}

　

package kaoshi;
import java.util.*;
public class Student{
	private String username;
	private String password;
	public Student(String username,String password){
		this.username=username;
		this.password=password;
	}
	public String[] exam(ArrayList<Question> paper){
		String[] answers=new String[paper.size()];
		Scanner input=new Scanner(System.in);
		for(int i=0;i<paper.size();i++){
			Question qs=paper.get(i);//题干+答案
			//System.out.println(qs);
			System.out.println((i+1)+"."+qs.getTitle());
			System.out.println("请您开始答题，A B C D");
			answers[i]=input.nextLine();
		}
		return answers;
	}
	public String getUsername(){
		return username;
	}
	public String getPassword(){
		return password;
	}
	
}

　

package kaoshi;
import java.util.*;
public class Teacher{
	public int piJuan(ArrayList<Question> a,String[] answer){//试卷（含答案），学生的答案		
		int total=0;
		for(int i=0;i<a.size();i++){
			if(a.get(i).getAnswer().equalsIgnoreCase(answer[i])){//不区分大小写
				System.out.println("第"+(i+1)+"题回答正确！");
				total+=(100/a.size());
			}
		}
		return total;
		
	}
}

　

package kaoshi;
import java.util.*;
public class TestMain{
	public static void main(String[] args){
		/*
		String question="1.如何哪个选项不是java基本数据类型？
  A.String	B.char	C.int	D.double";
		System.out.println(question);
		String answer="A";
		
		//如何将题目和答案放一起
		//String[],String,HashMap,Array,对象
		Question q=new Question("1.如何哪个选项不是java基本数据类型？
  A.String	B.char	C.int	D.double","A");
		//Question q=new Question("1.如何哪个选项不是java基本数据类型？
  A.String	B.char	C.int	D.double","A");
		System.out.println(q.getTitle());
		System.out.println(q.getAnswer());
		*/
		Machine m=new Machine();
		Scanner input=new Scanner(System.in);//输入
		System.out.println("欢迎进入考试系统");
		System.out.println("请输入用户名：");
		String name=input.nextLine();
		System.out.println("请输入密码：");
		String ps=input.nextLine();
		Student s=new Student(name,ps);//学生	
				
		if(m.login(s.getUsername(),s.getPassword())){
			System.out.println("登录成功!
"+s.getUsername()+":开始考试，请不要作弊!");
			ArrayList<Question> t=m.getPaper();	//试卷；
			System.out.println("考试机正在随机的生成试卷，请耐心等待一会");
			try{
				Thread.sleep(5000);//睡5s
			}catch(Exception e){
				e.printStackTrace();
			}
			String[] sresult=s.exam(t);//学生答案
			Teacher th=new Teacher();//老师
			int result=th.piJuan(t,sresult);
			System.out.println(s.getUsername()+"此次考试最终成绩："+result+"分");	
		}else{
			System.out.println("账号或密码错误！");
		}
	}
}