bookclass.java

J2EE网络书店系统 采用JSP , servlet ,javabean开发 初学者可以参考

/*
 * 创建日期 2005-3-9
 *
 * TODO 要更改此生成的文件的模板，请转至
 * 窗口 － 首选项 － Java － 代码样式 － 代码模板
 */
package store;

import javax.servlet.http.HttpServletRequest;
import java.util.Vector;
import java.sql.ResultSet;

/**
 * @author wwx
 *
 * TODO 要更改此生成的类型注释的模板，请转至
 * 窗口 － 首选项 － Java － 代码样式 － 代码模板
 */
public class BookClass {
	private long id;
	private String classname;
	
	public BookClass()
	{
	
	}
	
	public void SetId(long i)
	{
		id = i;
	}
	
	public void SetClassName(String s)
	{
		classname = s;
	}
	
	public String GetId()
	{
		return String.valueOf(id);
	}
	
	public String GetClassName()
	{
		return classname;
	}
	
	public void AddClass(HttpServletRequest httpservletrequest) throws Exception
	{
		String s = null;
		boolean flag = false;
		String s1 = ParamUtils.getString(httpservletrequest, "classname", "");
		
		if(s1.equals("") || s1 == null)
		{
			s = s + "You have not input the name of class!<br>";
			flag = true;
		}
		
		if(!flag)
		{
			DBConnect dbconnect = new DBConnect();
			dbconnect.prepareStatement("insert into My_BookClass (classname) values (?)");
			dbconnect.setString(1, s1);
			dbconnect.executeUpdate();
			dbconnect.close();
		}
		else
		{
			throw new Exception(s);
		}
	}
	
	public void UpdateClass(HttpServletRequest httpservletrequest) throws Exception
	{
		String s = null;
		boolean flag = false;
		String s1 = ParamUtils.getString(httpservletrequest, "id", "");
		String s2 = ParamUtils.getString(httpservletrequest, "classname", "");
		
		if(s1.equals("") || s1 == null)
		{
			s = s + "You have not input the id!<br>";
			flag = true;
		}
		if(s2.equals("") || s2 == null)
		{
			s = s + "You have not input the name of class!<br>";
			flag = true;
		}
		
		if(!flag)
		{
			DBConnect dbconnect = new DBConnect();
			dbconnect.prepareStatement("update My_BookClass set classname=? where id=?");
			dbconnect.setString(1, s2);
			dbconnect.setLong(2, Long.parseLong(s1));
			dbconnect.executeUpdate();
			dbconnect.close();
		}
		else
		{
			throw new Exception(s);
		}
	}
	
	public void DelClass(HttpServletRequest httpservletrequest) throws Exception
	{
		String s = "";
		boolean flag = false;
		String s1 = ParamUtils.getString(httpservletrequest, "id", "");
		String s2 = ParamUtils.getString(httpservletrequest, "classname", "");
		if(s1.equals("") || s1 == null)
		{
			s = s + "You have not input the id!<br>";
			flag = true;
		}
		if (!flag)
		{
			//先删除该类下的图书
			httpservletrequest.setAttribute("field","bookclass");
			httpservletrequest.setAttribute("keyword",s1);
			Book.DelBook(httpservletrequest);
			DBConnect dbconnect = new DBConnect();
			dbconnect.prepareStatement("delete from My_bookclass where id = ?");
			dbconnect.setLong(1, Long.parseLong(s1));
			dbconnect.executeUpdate();
			dbconnect.close();
		}
		else
		{
			throw new Exception(s);
		}
		
	}
	
	public Vector LoadClasses() throws Exception
	{
		Vector vector = new Vector();
		DBConnect dbconnect = new DBConnect();
		dbconnect.prepareStatement("select * from My_bookclass");
		BookClass bookclass;
		for(ResultSet resultset = dbconnect.executeQuery(); resultset.next(); vector.add(bookclass))
		{
			bookclass = new BookClass();
			bookclass.SetId(resultset.getLong("id"));
			bookclass.SetClassName(resultset.getString("classname"));
		}
		dbconnect.close();
		return vector;
	}

}