work.java

一个用JAVA编写的学生管理系统

import java.lang.*;
import java.io.*;
import java.util.*;



//surname,given_name,email,date_of_birth,telephone

public class work
{
  public static Hashtable command = new Hashtable();
  public static Hashtable studTable = new Hashtable();
  public static Hashtable empTable = new Hashtable();
  public static Hashtable subjectTable = new Hashtable();

	public static void main(String[] args)
	{

		if(!processData())
		{
			System.out.println("create File failed!");
			return;
		}

		work oWork = new work();
		String ans = "";
		while(!ans.equals("q"))
		{
			System.out.println("#");
                      try{
                        BufferedReader br1=new BufferedReader(new InputStreamReader(System.in));
                         ans = trim(br1.readLine());
                      }catch(IOException ex)
                      {
                        System.out.println(ex.toString() );
                      }
			int CMD = getCommIndex(oWork.getCommand(ans));
			switch(CMD)
			{
                          case 0:oWork.addStudent(ans);
                                break;
                                case 1:oWork.addEmployee(ans);
                                break;
                                case 2: oWork.editStudent(ans);
                                break;
                                case 3: oWork.editEmployee(ans);
                                break;
                                case 4:oWork.del(ans);
                                break;
                                case 5:oWork.delAll(ans);
                                break;
                                case 6:oWork.listbyID(ans);
                                break;
                                case 7: oWork.listStaff(ans);
                                break;
                                case 8: oWork.listAcad(ans);
                                break;
                                case 9:oWork.listStud(ans);
                                break;
                                case 10:oWork.listAll(ans);
                                break;
                                case 11:oWork.save();
                                break;
                              case 12:oWork.create_subject(ans);
                                break;
                              case 13:oWork.enrol(ans);
                                break;
                              case 14:oWork.unenrol(ans);
                                break;
                              case 15:oWork.assign(ans);
                                break;
                              case 16:oWork.unassign(ans);
                                break;
                              case 17:oWork.set_prereq(ans);
                                break;
                              case 18:oWork.get_prereqs(ans);
                                break;
                              case 19:oWork.count_staff();
                                break;
                              case 20:oWork.count_acad();
                                break;
                              case 21:oWork.count_student();
                                break;
                              case 22:oWork.count_employee();
                                break;
                              case 23:oWork.count_all();
                                break;
                              case 24:
				break;
				default:
					System.out.println("bad command for " +ans);

			}
		}

	}

  /*
      > COUNT_STAFF

> COUNT_ACADEMICS

> COUNT_STUDENTS

> COUNT_EMPLOYEES

> COUNT_ALL

        CREATE_SUBJECT subject_code,subject_title

ENROL student_id:subject_code

UNENROL student_id:subject_code

ASSIGN academic_id:subject_code

UNASSIGN academic_id:subject_code

SET_PREREQ subject_code:subject_code

GET_PREREQS subject_code


        */

	//add a student
	public void addStudent(String strInfo)
	{
		String strTemp = strInfo;
		int pos = strTemp.indexOf(" ");
		strTemp = trim(strTemp.substring(pos+1,strTemp.length()));
		StringTokenizer st = new StringTokenizer(strTemp,",");
		if(st.countTokens()<6)
		{
			System.out.println("bad input student information! ");
                        System.out.println(" -- ADD_STUDENT idnum,surname,given_name,email,date_of_birth,telephone");
			return;
		}

		String studNum = st.nextToken();
		if(!studNum.startsWith("stud"))
		{
			System.out.println("error input student id! please input start with \"stud\" ")	;
			return;
		}

		studInfo si = new studInfo();
		si.setSurname(st.nextToken());
		si.setGiven_name( st.nextToken());
		si.setEmail( st.nextToken());
		si.setDate_of_birth ( st.nextToken());
		si.setTelephone( st.nextToken());
		si.setSubject_code("");

		studTable.put(studNum,si);
	}
	// add a employee;
	public void addEmployee(String strInfo)
	{
		String strTemp = strInfo;
		int pos = strTemp.indexOf(" ");
		strTemp = trim(strTemp.substring(pos+1,strTemp.length()));
		StringTokenizer st = new StringTokenizer(strTemp,",");
		if(st.countTokens()<7)
		{
			System.out.println("bad input student information! ");
			return;
		}
		String empNum = st.nextToken();
		if(!empNum.startsWith("acad")&&!empNum.startsWith("staff"))
		{
			System.out.println("error input employee id!" )	;
			return;
		}
                empInfo info = new empInfo();
		if(empNum.startsWith("acad"))
                {
                 info = new acadInfo();
                }
                info.setSurname(st.nextToken());
                info.setGiven_name( st.nextToken());
                info.setEmail( st.nextToken());
                info.setDate_of_birth ( st.nextToken());
		info.setTelephone( st.nextToken());
		info.setSalary( st.nextToken());

		empTable.put(empNum,info);

	}
	//Edit a student information;
	public void editStudent(String strInfo)
	{
		String strTemp = strInfo;
		int pos = strTemp.indexOf(" ");
		strTemp = trim(strTemp.substring(pos+1,strTemp.length()));
                int subPos = strTemp.indexOf(":");
                String studNum = strTemp.substring(0,subPos);
                String strContent = this.trim(strTemp.substring(subPos+1,strTemp.length() ));
		StringTokenizer st = new StringTokenizer(strContent,",");

		if(st.countTokens()<5)
		{
			System.out.println("bad input student information! ");
			return;
		}
		//String studNum = st.nextToken();
		if(!studNum.startsWith("stud"))
		{
			System.out.println("error input student id! please input start with \"stud\" ")	;
			return;
		}

			if(studTable.size()==0)
			{
				System.out.println("no records!");

				return;
			}
			studInfo si =(studInfo) studTable.get(studNum);
			if(si!=null)
			{
                          si.surname = st.nextToken();
                          si.given_name = st.nextToken();
                          si.email = st.nextToken();
                          si.date_of_birth = st.nextToken();
                          si.telephone = st.nextToken();

			}else
                        {
                          System.out.println("No record match the student id number:"+studNum);
                          return;
                        }

	}
	// edit employee
	public void editEmployee(String strInfo)
	{
          String strTemp = strInfo;
                  int pos = strTemp.indexOf(" ");
                  strTemp = trim(strTemp.substring(pos+1,strTemp.length()));
                  int subPos = strTemp.indexOf(":");
                  String studNum = strTemp.substring(0,subPos);
                  String strContent = this.trim(strTemp.substring(subPos+1,strTemp.length() ));
                  StringTokenizer st = new StringTokenizer(strContent,",");
     		if(st.countTokens()<6)
		{
			System.out.println("bad input student information! ");
			return;
		}

		if(!studNum.startsWith("acad")&&!studNum.startsWith("staff"))
		{
			System.out.println("error input employee id")	;
			return;
		}

                if(empTable.size()==0)
                 {
                              System.out.println("no records!");
                              return;
                 }
                        empInfo ei  =(empInfo) studTable.get(studNum);
                        if(ei!=null)
                        {
                                ei.surname = st.nextToken();
                                ei.given_name = st.nextToken();
                                ei.email = st.nextToken();
                                ei.date_of_birth = st.nextToken();
                                ei.telephone = st.nextToken();
                                ei.salary = st.nextToken();
                        }else
                        {
                          System.out.println("No record match the student id number:"+studNum);
                          return;
                        }

	}

        //save Hashtable to persist data
        public void save()
        {
          if(!saveTableToFile("studInfo",work.studTable )) return;
          if(!saveTableToFile("empInfo",work.empTable )) return;
          if(!saveTableToFile("subjectInfo",work.subjectTable )) return;
        }
        // save hashtable to persist data file
        private boolean saveTableToFile(String file_name,Hashtable table)
        {
          if(table!=null)
          {
            System.out.println("please given hashtable!");
            return false;
          }
          if(file_name.equals("")||file_name==null)
          {
            System.out.println("please input filename !");
            return false;
          }
           try
               {
                       ObjectOutputStream out = new  ObjectOutputStream(new FileOutputStream(file_name,false));
                       out.writeObject(table);
                       out.flush();
                       out.close();
               }catch(Exception ex)
               {
                       System.out.println("write file err: "+ ex +"\n\r please check filename!");
                       return false;
               }

               return true;
        }
	//del
	public void del(String strInfo)
	{
		String strTemp = strInfo;
		int pos = strTemp.indexOf(" ");
		strTemp = trim(strTemp.substring(pos+1,strTemp.length()));

		if(strTemp.equals("")||strTemp==null)
		{
			System.out.println("please input id number! ");
			return;
		}
		String studNum = strTemp;

		/*	if(studTable.size()==0)
			{
				System.out.println("no records!");
				return;
			}
		*/
                if(studTable.containsKey(studNum))
		{
			studTable.remove(studNum);
		}else if(empTable.containsKey(studNum))
                {
                  empTable.remove(studNum);
                }else