dbasvlt.java

采用基于B/S结构进行开发学生管理信息系统,本系统采用Servlet+Jsp+JavaBean+MySQL 的设计方式

import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
import myBean.DBA;

public class DBASvlt extends HttpServlet{
	
public void doGet(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {
    
    String id =req.getParameter("id");
    int success = 0;
    String action = req.getParameter("action");
    DBA dba = null;
    String message="";
    String name,password,enrol;
   	
   if ("new".equalsIgnoreCase(action)) {
   	  name=new String(req.getParameter("name").getBytes("ISO8859_1"));
      password= req.getParameter("password");
      enrol =req.getParameter("enrol");
   	 
   	  if(isTrue(req,res,id,name,password,enrol) && hasLogin(req,res,id)){

        dba = doNew(req,res,id,password,name,enrol);      
        sendBean(req, res, dba, "/getDBA.jsp");
        }
    }  
    
    if ("update".equalsIgnoreCase(action)) {    	
      name=new String(req.getParameter("name").getBytes("ISO8859_1"));
      password= req.getParameter("password");
      enrol = req.getParameter("enrol");
      
      if(isTrue(req,res,id,name,password,enrol)){
    	   try{		
     	       dba = doUpdate(req,res,id,password,name,enrol);
     	       sendBean(req,res,dba,"/getDBA.jsp");
            }
     	   catch(SQLException e){} 
     	  }
    }
			   
    if ("delete".equalsIgnoreCase(action)) {
    	try{			
      	success = doDelete(id);	
      	    }
      	    catch(SQLException e){}				
    	if (success != 1) {
    		doError(req, res, "DBASvlt: Delete unsuccessful. Rows affected: " + success);
    	} else {
    		res.sendRedirect("http://localhost:8080/0903/getDBA.jsp");
    	}
   
    }
    }
    

 public DBA doNew(HttpServletRequest req,HttpServletResponse res,String id,String password,String name,String enrol )
                           throws ServletException,IOException{
                           
      DBA dba= new DBA(); 
      String dep = req.getParameter("dep");
      String sex = new String(req.getParameter("sex").getBytes("ISO8859_1"));
      String info = new String(req.getParameter("info").getBytes("ISO8859_1"));            	
   
      dba.setId(id);
      dba.setName(name);
      dba.setPassword(password);
      dba.setDep_id(dep);
      dba.setSex(sex);
      dba.setInfo(info);
      dba.setEnrol(enrol);
     
      dba.addDBA(); 
      return dba;                	           	
 	}

 public DBA doUpdate(HttpServletRequest req,HttpServletResponse res , String id,String password,String name,String enrol)
                           throws ServletException,IOException,SQLException { 
                           	                     	
    DBA dba = new DBA();             
    String dep = req.getParameter("dep");
    String sex = new String(req.getParameter("sex").getBytes("ISO8859_1"));
    String info = new String(req.getParameter("info").getBytes("ISO8859_1"));
    
    dba.setEnrol(enrol);
    dba.setId(id);
    dba.setName(name);
    dba.setPassword(password);
    dba.setDep_id(dep);
    dba.setSex(sex);
    dba.setInfo(info);  
    dba.updateDBA();
  
		return dba;
  }

  public int doDelete(String id) throws SQLException {
  	int num=0;
    DBA dba=new DBA();
    num=dba.deleteDBA(id);
    return num;
  }
	
public void sendBean(HttpServletRequest req, HttpServletResponse res,
                       DBA dba, String target)
                       throws ServletException, IOException {
    req.setAttribute("dba", dba);
    RequestDispatcher rd = getServletContext().getRequestDispatcher(target);
    rd.forward(req, res);
  }
  
  
  public void doError(HttpServletRequest req,
                      HttpServletResponse res,
                      String str)
                      throws ServletException, IOException {


    req.setAttribute("problem", str);
    RequestDispatcher rd = getServletContext().getRequestDispatcher("/errorpage.jsp");
    rd.forward(req, res);
  }
  
  public boolean hasLogin(HttpServletRequest req, HttpServletResponse res,String id)
  throws ServletException, IOException{
  	boolean f=true;
  	String message="对不起，该帐号已经被注册过了!";
  	DBA dba= new DBA();
  	f= dba.hasLogin(id);
  	if(f==false){
  	doError(req,res,message);	
  		}
  		return f;
  	}
  
  public boolean isTrue(HttpServletRequest req, HttpServletResponse res,
                        String id,String name,String password,String enrol)
                        throws ServletException, IOException {
   boolean f=true;                     	
   String message ="";
   if(id==null || id.equals(""))  {
   	f=false;
   	message="错误，管理员帐号不能为空！";
   	doError(req,res,message);	}
   
   else if(name==null || name.equals(""))  {
   	f=false;
   	message="管理员姓名不能为空，请重新填写！";
   	doError(req,res,message);	}
  	
       
   else if(password==null || password.equals(""))  {
   	f=false;
   	message="密码不能为空，请重新填写！";
   	doError(req,res,message);	}  
   else if(enrol==null || enrol.equals("")) {
   	f=false;
   	message="注册日期不能为空,请重新填写!";
   	doError(req,res,message);}

     return f;
     
  }
  
  public void doPost(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {

    doGet(req, res);

  }
	
	
}