bookcategorydao.java

图书管理系统

/**
 * 图书类别的操作类
 */
package fuguo.yy1.dao;

/**
 * @author cankongyun
 *
 */

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;

import fuguo.yy1.base.BaseDAO;
import fuguo.yy1.db.DBConn;
import fuguo.yy1.dto.BookCategory;
import fuguo.yy1.util.SQLConstants;

public class BookCategoryDAO implements BaseDAO {

	private static Connection con=DBConn.getConnection();
	private static PreparedStatement pstmt=null;
	private static ResultSet rs=null;
	
	
	/**
	 * 显示所有的图书类别
	 * @return ArrayList
	 */
	public static ArrayList bookCategorys(){
		ArrayList al=new ArrayList();
		BookCategory bookCategory=null;
		try{
			pstmt=con.prepareStatement(SQLConstants.SELECT_BOOKCATEGORYS);
			rs=pstmt.executeQuery();
			while(rs.next()){
				bookCategory=new BookCategory();
				bookCategory.setCategoryId(rs.getInt("bookCategoryId"));
				bookCategory.setCategoryName(rs.getString("categoryName"));
				//将bookCategory对象加入al容器中
				al.add(bookCategory);	
			}
			DBConn.releaseConnection(rs,pstmt,null);
		}catch(SQLException se){
			System.err.println("显示所有图书类别失败!出现异常:"+se.getMessage());
		}
		return al;
	}
	
	
    /**
     * 检测图书类别是否存在方法
     * @param _categoryName
     * @return boolean
     */
    public static boolean checkCategoryName(String _categoryName)
    {
        boolean exist = false;
        try
        {
            pstmt = con.prepareStatement(SQLConstants.SELECT_CHECK_CATEGORYNAME);
            pstmt.setString(1, _categoryName);
            rs = pstmt.executeQuery();
            exist = rs.next();
            DBConn.releaseConnection(rs,pstmt,null);
        }catch(SQLException se){
            System.err.println("检测图书类别是否存在失败！出现异常："+se.getMessage());
        }
        return exist;
    }
    
    
    /**
     * 增加图书类别的方法
     * @param _baseDTO
     * @return int
     */
    public static int insertCategory(BookCategory _bookCategory){
    	int result=0;
    	
        try{
            StringBuffer INSERT_BOOKCATEGORY = new StringBuffer();
            INSERT_BOOKCATEGORY.append("insert into bookCategory(categoryName)");
            INSERT_BOOKCATEGORY.append(" values(?)");
            pstmt = con.prepareStatement(INSERT_BOOKCATEGORY.toString());
            pstmt.setString(1, _bookCategory.getCategoryName());

            result = pstmt.executeUpdate();

            DBConn.releaseConnection(null,pstmt,null);
       }catch(SQLException se)            {
            System.out.println("添加图书类别失败！出现异常："+se.getMessage());
       }
    	
    	return result;
    	
    }
    
    
    
    /**
     * 根据图书类别Id查询类别信息
     * @param _categoryId
     * @return BookCategory
     */
    public static BookCategory selectBookCategoryById(int _bookCategoryId){
    	BookCategory bookCategory=null;
    	
    	try{
    		pstmt=con.prepareStatement(SQLConstants.SELECT_BOOKCATEGORY_ID);
    		pstmt.setInt(1,_bookCategoryId);
    		rs=pstmt.executeQuery();    		
    		
    		while(rs.next()){
    			bookCategory=new BookCategory();
    			bookCategory.setCategoryId(rs.getInt("bookCategoryId"));
    			bookCategory.setCategoryName(rs.getString("categoryName"));
    			
    			return bookCategory;   			
    		}
    		DBConn.releaseConnection(rs,pstmt,null);
    		
    	}catch(SQLException se){
    		System.err.println("根据Id查询用户信息失败！出现异常："+se.getMessage());
    	}
    	
    	return null;
    }
    
    
    /**
     * 修改图书类别
     * @param _bookCategoryId
     * @param _baseDTO
     * @return int
     */
    public static int updateBookCategory(int _bookCategoryId,BookCategory _bookCategory){
    	
    	int result=0;
        try
        {
            pstmt = con.prepareStatement(SQLConstants.UPDATE_BOOKCATEGORY);
            pstmt.setString(1, _bookCategory.getCategoryName());
            pstmt.setInt(2,_bookCategoryId);
            result = pstmt.executeUpdate();
            DBConn.releaseConnection(null,pstmt,null);
        }
        catch(SQLException se){
            System.err.println("修改图书类别信息失败！出现异常："+se.getMessage());
        }
    	return result;
    	
    }
    
    
    /**
     * 删除图书类别
     * @param _bookCategoryId
     * @return int
     */
    public static int deleteCategory(int _bookCategoryId){
    	int result=0;
    	try{

    		pstmt=con.prepareStatement(SQLConstants.DELETE_BOOKCATEGORY);
    		pstmt.setInt(1,_bookCategoryId);
    		result=pstmt.executeUpdate();
    		
    		DBConn.releaseConnection(null,pstmt,null);
    	}catch(SQLException se){
    		
    		System.err.println("删除图书类别信息失败，出现异常："+se.getMessage());
    	}
    	return result;
    }
    
    
}