departmentsvlt.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.Department;

public class DepartmentSvlt extends HttpServlet{
	
public void doGet(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {
          	
    String dep_id =req.getParameter("id");
    int success = 0;
    String action = req.getParameter("action");
    Department dep = null;
    String name,message="";
    
    
    if ("new".equalsIgnoreCase(action)) {
      name=new String(req.getParameter("name").getBytes("ISO8859_1"));
      if(isTrue(req,res,dep_id,name) && hasLogin(req,res,name)){
          dep = doNew(req,res,dep_id,name);
          sendBean(req, res, dep, "/getDepartment.jsp");
        }
    }  
    
    if ("update".equalsIgnoreCase(action)) {
        name=new String(req.getParameter("name").getBytes("ISO8859_1"));                   
        if(isTrue(req,res,dep_id,name) && hasLogin(req,res,name)){
    	    try{		
     	       dep = doUpdate(req,res,dep_id,name);
     	       sendBean(req,res,dep,"/getDepartment.jsp");
     	    }
     	  catch(SQLException e){} 
     	 }
    }
			   
    if ("delete".equalsIgnoreCase(action)) {
    	try{			
      	success = doDelete(dep_id);	
      	    }
      	    catch(SQLException e){}				
    	if (success != 1) {
    		doError(req, res, "DepartmentSvlt: Delete unsuccessful. Rows affected: " + success);
    	} else {
    		res.sendRedirect("http://localhost:8080/0903/getDepartment.jsp");
    	}  
    }
    }
    
    
     public Department doNew(HttpServletRequest req,HttpServletResponse res,String dep_id,String name)
                           throws ServletException,IOException{                     	
      String cname=new String (req.getParameter("cname").getBytes("ISO8859_1"));
      Department dep= new Department();
      
      dep.setId(dep_id);
      dep.setName(name);
      dep.setCname(cname);
      dep.setClass_count(0);
      dep.addDepartment();
      return dep;                	
                           	
   	}
                           	
                           	
      public Department doUpdate(HttpServletRequest req,HttpServletResponse res ,String id,String name)
                           throws ServletException,IOException,SQLException {                      	 
        String cname = new String(req.getParameter("cname").getBytes("ISO8859_1"));
        Department dep = new Department();
   
        dep.setId(id);
        dep.setName(name);
        dep.setCname(cname); 
        dep.update();
		    return dep;
      }
  
    public int doDelete(String id) throws SQLException {
    	 int num = 0;
       Department dep=new Department();
       num = dep.delete(id);
       return num;
    }
  
  public void sendBean(HttpServletRequest req, HttpServletResponse res,
                       Department dep, String target)
                       throws ServletException, IOException {
    req.setAttribute("dep", dep);
    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 name)
      throws ServletException, IOException{
  	boolean f=true;
  	String message="对不起，该学院已经被注册过了!";
  	Department dep= new Department();
  	f= dep.hasLogin(name);
  	if(f==false){
  	   doError(req,res,message);	
  	}
  	return f;
  	}
  	
  	
  public boolean isTrue(HttpServletRequest req, HttpServletResponse res,String dep_id,String name)
                        throws ServletException, IOException {
     boolean f=true;                     	
     String message ="";
    if(name==null || name.equals(""))  {
   	   f=false;
   	   message="错误,院系名称不能为空！";
   	   doError(req,res,message);	
   	}else if(dep_id==null || dep_id.equals("")){
   		f=false;
   		message="错误，学院代号不能为空！";
   		doError(req,res,message);
   	}
     return f;
     
  }
  
    public void doPost(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {

    doGet(req, res);

  }
   
   
   }