op_bookclass.java

这个是我自己写的网上书店的管理系统

package run;

import java.util.*;
import util.*;
import book.*;
import java.sql.*;
import java.lang.String;
import javax.servlet.http.HttpServletRequest;

public class op_bookclass extends Database
{
	  public op_bookclass() {
	  }
	  private bookclass bookclass = new bookclass(); //图书分类对象
	  private javax.servlet.http.HttpServletRequest request; //建立页面请求
	  private Vector classlist;		//图书类别向量数组
	  public Vector getClasslist() {
	        return classlist;
	          }
	  public String getBookClassSql()    //将图书类别表中的所有数据查找出来，按照ID的顺序来进行排列
	  {
	                  sqlStr = "select id,classname from bookclass order by id";
	                  return sqlStr;
	  }
	  
	  //查询图书分类
	  public boolean seachBookClass() throws Exception 
	  {
	               int id = 0;
	               String classname = "";
	               int rscount = 0;
	               try 
	               {
	                  Database db = new Database();
	                  db.connect();
	                  sm = db.conn.createStatement ();
	                  rs = sm.executeQuery(getBookClassSql());
	                  rscount = sm.getMaxRows();
	                  classlist = new Vector(rscount+1);
	                  classlist.clear();
	                  while (rs.next())
	                  {
	                                  id = rs.getInt("id");
	                                  classname = rs.getString("classname");
	                                  bookclass bc = new bookclass(id,classname);
	                                  classlist.addElement(bc);
	                 }
	                          rs.close();
	                          return true;
	                }
	                catch (SQLException sqle)
	                {
	                       System.out.println(sqle);
	                       return false;
	                }
	    }
	  
	  
	//添加新图书分类时获得页面转递的分类名称
	public boolean getRequest(javax.servlet.http.HttpServletRequest newrequest) 
	{
	     boolean flag = true;
	     try
	     {
	         request = newrequest;
	         String bookclassname = request.getParameter("bookclassname");
	          if (bookclassname==null || bookclassname.equals(""))
	          {
	              bookclassname = "";
	              flag = false;
	          }
	          bookclass.setClassName(bookclassname);
	          return flag;
	     }
	     catch (Exception e)
	     {
	            return false;
	     }
	}
	    //添加新的图书分类
	public boolean insert() throws Exception 
	{
	           sqlStr = "insert into bookclass (classname) values ('";
	           sqlStr = sqlStr + dataFormat.toSql(bookclass.getClassName()) + "')";
	                      try
	                      {      System.out.print(sqlStr);
	                        Database db = new Database();
	                              db.connect();
	                              sm =db.conn.createStatement ();
	                              sm.execute(sqlStr);
	                              return true;
	                      }
	                      catch (SQLException sqle)
	                      {        System.out.print(sqle.getMessage());
	                              return false;
	                      }
	              }
	
	//删除新的图书分类
	public boolean delete( int aid ) throws Exception 
	{
	               sqlStr = "delete from bookclass where id = "  + aid ;
	               try
	               {         Database db = new Database();
	                          db.connect();
	                          sm =db.conn.createStatement ();
	                       sm.execute(sqlStr);
	                       return true;
	               }
	               catch (SQLException e)
	               {
	                       System.out.println(e);
	                       return false;
	               }
	       }
}