op_book.java

图书管理系统,用JSP实现,图书的查询,添加等功能

package guanli;
/**
 * 图书类 
 */

import java.sql.*;
import java.util.Vector;
import beans.*;

public class op_book extends DataBase{
        private javax.servlet.http.HttpServletRequest request; //建立页面请求
		private boolean sqlflag = true ;		    //对接收到的数据是否正确
		private Vector booklist;			    //显示图书列表向量数组
		String sqlStr="";
		public Vector getBooklist() {
				return booklist;
		}
		public boolean getSqlflag() {
				return sqlflag;
		}
		public String to_String( String str) {
				try
				{
						return new String(str.getBytes("ISO8859-1"));
				}
				catch (Exception e)
				{
						return str;
				}
		}
	    /**
			 * 获得查询图书类别的sql语句
		*/
		public String getSql() {
			 sqlStr = "select Id,ClassName from book order by Id";
			 return sqlStr;
			}
		
		/**
	     * 图书的单本查询
		*/
  public boolean getOnebook(int newid ) throws Exception {
	 DataBase db = new DataBase();
	 db.connect();
	 stmt =db.conn.createStatement ();
	 try {
		sqlStr = "select   a.Id,a.BookName,a.BookClass,b.ClassName,"+
				   "a.Author,a.Publish,a.BookNo,a.Content,a.Price,a.Amount,"+
				   "a.Leav_number,a.RegTime,a.picture from book a,bookclass b"+
				  " where a.BookClass = b.Id  and a.Id = "+ newid;
						rs = stmt.executeQuery(sqlStr);
						if (rs.next())
						{	booklist = new Vector(1);
							book book = new book();
							book.setId(rs.getLong("Id"));
							book.setBookName(rs.getString("BookName"));
							book.setBookClass(rs.getInt("BookClass"));
							book.setClassname(rs.getString("ClassName"));
							book.setAuthor(rs.getString("Author"));
							book.setPublish(rs.getString("Publish"));
							book.setBookNo(rs.getString("BookNo"));
							book.setContent(rs.getString("Content"));
							book.setPrice(rs.getFloat("Price"));
							book.setAmount(rs.getInt("Amount"));
							book.setLeav_number(rs.getInt("Leav_number"));
							book.setRegTime(rs.getString("RegTime"));
							book.setPicture(rs.getString("picture"));
							booklist.addElement(book);
						} else {
								rs.close();
								return false;
						}
						rs.close();
						return true;
				}
				catch (SQLException e)
				{
						return false;
				}
		}
}