Qly Sinh Vien

Main.java

package qlysv;


public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        int n,a=0,b=0,c=0;
	System.out.print("So luong thi sinh: ");
	n=NhapDL.nhapInt();
	KhoiA TSA[]=new KhoiA[n];
	KhoiB TSB[]=new KhoiB[n];
	KhoiC TSC[]=new KhoiC[n];
	System.out.println("--------NHAP THONG TIN---------");
        for(int j=0;j<n;j++)
	{	int KhoiThi=TuyenSinh.nhapKT();
			switch (KhoiThi)
                        {
                                case 1:
					TSA[a]=new KhoiA("Toan","Ly","Hoa");
					TuyenSinh.Nhapts(TSA[a]);
					a++;
					break;
				case 2:
					TSB[b]=new KhoiB("Toan","Hoa","Sinh");
					TuyenSinh.Nhapts(TSB[b]);
					b++;
					break;
				case 3:
					TSC[c]=new KhoiC("Van","Su","Dia");
					TuyenSinh.Nhapts(TSC[c]);
					c++;
					break;
				default: System.out.println();
                        }
        }
        System.out.println("----------HIEN THI------");
	for(int j=0;j<n;j++)
		{
		if (TSA[j]!=null)
			TuyenSinh.OutputData(TSB[j]);
                else
                    System.out.println("Khong co sinh vien khoi A");
                }
    }

}

NhapDL.java

package qlysv;
import java.io.*;
public class NhapDL
{
    static DataInputStream str=new DataInputStream(System.in);
    public static String nhapchuoi()
    {
        String st="";
        try {
            st=str.readLine();
        }catch(Exception e){
            System.out.println("Loi" +e);
        }
        return st;
    }
    public static int nhapInt()
    {
        String st=NhapDL.nhapchuoi();
        int i=0;
        try{
            i=Integer.valueOf(st).intValue();
        }catch(Exception e){
                System.out.println("Loi" +e);
        }
        return i;
    }
}

ThiSinh.java

package qlysv;
public class ThiSinh {
    protected String sHoTen, sDiaChi, sUT;
    protected int iSoBD;
    public ThiSinh()
    {}
}
public class KhoiA extends ThiSinh{
    protected String sMon1,sMon2,sMon3;
    KhoiA()
    {}
    KhoiA(String m1,String m2,String m3)
    {
        sMon1=m1;
        sMon2=m2;
        sMon3=m3;
    }
}
public class KhoiB extends KhoiA {
    KhoiB()
    {}
    KhoiB(String m1,String m2,String m3)
    {
        sMon1=m1;
        sMon2=m2;
        sMon3=m3;
    }
}


public class KhoiC extends KhoiA{
    KhoiC()
    {}
    KhoiC(String m1,String m2,String m3)
    {
        sMon1=m1;
        sMon2=m2;
        sMon3=m3;
    }
}

TuyenSinh.java

package qlysv;

public class TuyenSinh {
    public static void Nhapts(ThiSinh ts)
    {
        System.out.print("SBD: ");
        ts.iSoBD=NhapDL.nhapInt();
        System.out.print("Ho va ten: ");
        ts.sHoTen=NhapDL.nhapchuoi();
        System.out.print("Dia Chi: ");
        ts.sDiaChi=NhapDL.nhapchuoi();
        System.out.print("Uu tien: ");
        ts.sUT=NhapDL.nhapchuoi();
    }
    public static void OutputData(KhoiA ts)
    {
        System.out.println("------------------");
        System.out.println("SBD: " +ts.iSoBD);
        System.out.println("Ho va ten: " +ts.sHoTen);
        System.out.println("Dia Chi: " +ts.sDiaChi);
        System.out.println("Uu tien: " +ts.sUT);
        System.out.println("Mon 1: " +ts.sMon1);
        System.out.println("Mon 2: " +ts.sMon2);
        System.out.println("Mon 3: " +ts.sMon3);
    }
    public static boolean ssXau(String st1,String st2)
    {
        if(st1.equalsIgnoreCase(st2)) return false;
        else return true;
    }
    public static int nhapKT()
    {
        String kt;
        System.out.print("Khoi thi: ");
        do{
            kt=NhapDL.nhapchuoi();
            if(ssXau(kt,"A")&&(ssXau(kt,"B"))&&(ssXau(kt,"C")))
                System.out.println("Ban chi co the nhap A or B or C");
        }while(ssXau(kt,"A")&&ssXau(kt,"B")&&ssXau(kt,"C"));
        if (ssXau(kt,"A")==false) return 1;
				else
				   if (ssXau(kt,"B")==false) return 2;
				   else
                                        if (ssXau(kt,"C")==false) return 3;
                                        else return 0;
    }

}