serverpool.java~1~

试题库管理系统 该系统所包含的子系统有：用户管理子系统、课程管理子系统、习题管理子系统和试卷库管理子系统。而用户管理子系统下分的模块有：添加用户、删除用户和修改用户信息；课程管理子系统下分的模块有：创

    }
    /**
     * 响应客户端的修改、添加命令
     */
    public void receive(){
        Vector SQLbean=new Vector();
        String sql;
        try {
            while(true){
                sql=bufin.readLine();     //接收客户端的SQL语句
                if(sql.equals("over")) break;
                SQLbean.addElement(sql);
            }
          Statement  st = conn.createStatement();
          for(int i=0;i<SQLbean.size();i++)
          {
            st.executeUpdate(SQLbean.elementAt(i).toString());  //执行SQL语句
            }
           st.close();
       }catch(SQLException ed){
           System.err.println(ed.toString());
       }catch(IOException ed){
            System.err.println(ed.toString());
       }
    }
    /**
     * 响应客户端的登录命令
     */
    public void login(){
         String ID;
         String password;
         String sql;
         ResultSet rt1,rt2;
        try {
            ID = bufin.readLine();         //接收客户端的登录ID
            password=bufin.readLine();     //接收客户端的密码
        } catch (IOException ex) {
            prout.println("NET error");
            prout.flush();
            System.err.println(ex.toString());
            return;
        }
        for(int i=0;i<userContainer.size();i++){      //检查该用户ID是否已登录
            if(ID.equals(userContainer.elementAt(i))){
                prout.println("该用户已在异地登录");
                prout.flush();
                return;
            }
        }
      sql="select * from user where user_id='"+ID+"' and password='"+password+"';";
        try {
            Statement  st = conn.createStatement();
             rt1=st.executeQuery(sql);   //查询数据库
            if (rt1.next()) {            // 用户ID、密码正确
                prout.println("OK");
                prout.flush();
                id=ID;
                userContainer.addElement(ID);   //将用户ID添加到userContainer中
                prout.println(rt1.getString(2));
                prout.println(rt1.getString(4));
                prout.println(rt1.getBoolean(5));
                prout.println(rt1.getString(6));
                prout.println(rt1.getString(7));
                rt2=st.executeQuery("select course_name from user_course where user_id='"+ID+"';");
                while(rt2.next()){
                     prout.println(rt2.getString(1));   //发送用户所教课程名给客户端
                }
                prout.println("over");
                prout.flush();
                rt2.close();
            }
            else {     // 用户ID、密码不正确
              prout.println("用户ID或密码出错");
              prout.flush();
            }
          rt1.close();
          st.close();
        } catch (SQLException ex2) {
         prout.println("数据库读取失败");
         prout.flush();
         System.err.println(ex2.toString());
        }
    }
    /**
     * 下载试卷到客户端
     */
    public void load(){
        String readin, filechar;
        String filepath,answerpath;
        Statement st,st2;
        ResultSet rt;
        int i;
        try {
            readin = bufin.readLine();    //接收客户端的查询语句
            st = conn.createStatement();
            rt=st.executeQuery(readin);
            BufferedReader fileread=null;
            BufferedReader answerread=null;
            while(rt.next()){
                try{
                filepath=rt.getString("path");
                fileread=new BufferedReader(new FileReader(filepath));
                answerpath=filepath.substring(0,filepath.length()-8)+"answer.txt";
                answerread=new BufferedReader(new FileReader(answerpath));
              }catch (IOException ex) {
                    i=rt.getInt(1);
                //    System.err.println(ex.toString()+i);
                    try{
                       st2= conn.createStatement();
                       st2.executeUpdate("delete from test where test_id=" + i +";");
                       st2.close();
                  }catch (SQLException  exl) {
                      System.err.println(exl.toString()+i);
                  }
                    continue;
                }
                prout.println(rt.getString("course_name"));
                prout.println(rt.getString("user_name"));
                prout.println(rt.getString("test_type"));
                prout.println(rt.getString("date"));
                prout.flush();
                while((filechar=fileread.readLine())!=null){
                   prout.println(filechar);
                   prout.flush();
                }
                prout.println("fileover");
                prout.flush();
                fileread.close();
                fileread=null;
                while((filechar=answerread.readLine())!=null){
                    prout.println(filechar);
                    prout.flush();
                }
                prout.println("answerover");
                prout.flush();
                answerread.close();
                answerread=null;
            }
            rt.close();
            st.close();
          } catch (SQLException ex1) {
              System.err.println(ex1.toString());
          }catch (IOException ex) {
               System.err.println(ex.toString());
         }finally{
            prout.println("End");
            prout.flush();
        }
    }
    /**
     * 响应客户端上传试卷
     */
    public void transfer(){
        String readin,course_name,user_name,type,path;
        String sql="select test_id from test;";
        int test_id;
        String filename;
       PrintWriter fileout,answerout;
        Date datetime=new Date();
        java.text.SimpleDateFormat formatter = new java.text.SimpleDateFormat("yyyy-MM-dd");
        String date=formatter.format(datetime);           //获得当前系统时间
        try {
            Statement st = conn.createStatement();
            ResultSet rt=st.executeQuery(sql);
            if(rt.next()){
                rt.last();        //取最后一条记录
                test_id = rt.getInt(1);
            }else test_id=0;
            rt.close();
            st.close();
            sql="insert into test(course_name,user_name,test_type,path,date) values(?,?,?,?,'"+date+"');";
            PreparedStatement pst=conn.prepareStatement(sql);    //将上传试卷属性插入到数据库中去
                course_name= bufin.readLine();    //获得课程名属性
                test_id++;
                pst.setString(1,course_name);
                user_name=bufin.readLine();      //获得创建者属性
                pst.setString(2,user_name);
                type=bufin.readLine();        //获得试卷类型属性
                pst.setString(3,type);
                filename=test_id+"test.txt";
                path="test/"+filename;
                pst.setString(4,path);     //设计试卷路径属性
                pst.executeUpdate();   //执行插入语句
                pst.close();
               fileout=new PrintWriter(new FileOutputStream(path));
               while(true){
                    readin=bufin.readLine();
                    if(readin.equals("over"))break;
                    fileout.println(readin);
                    fileout.flush();
               }
          fileout.close();
          path=path.substring(0,path.length()-8)+"answer.txt";
          answerout=new PrintWriter(new FileOutputStream(path));
                         while(true){
                              readin=bufin.readLine();
                              if(readin.equals("over"))break;
                              answerout.println(readin);
                              answerout.flush();
                         }
                    answerout.close();
        } catch (IOException ex) {
             System.err.println(ex.toString());
        }catch (SQLException ex1) {
             System.err.println(ex1.toString());
        }
    }
}
}