bmpbookbean.java

演示简单Java语言基础

//引入相关包
import java.util.*;
import javax.ejb.*;
import javax.naming.*;
//这里需要引入sql处理包
import java.sql.*;
import javax.sql.*;
//BMP实体EJB的组件类
public class BmpBookBean implements EntityBean 
{
    //映射isbn 字段
    private String bookIsbn;
    //映射author 字段
    private String bookAuthor;
    //映射title 字段
    private String bookTitle;
    //映射price 字段
    private double bookPrice;
	private EntityContext ec;
	private DataSource ds;
	private Connection con;
    private String jndi ="bmpbook";
    //实现业务方法
    public void setBookAuthor(String bookAuthor)
    {
   		this.bookAuthor=bookAuthor;
    }
    public void setBookTitle(String bookTitle)
    {
        this.bookTitle=bookTitle;
    }
    public void setBookPrice(double bookPrice)
    {
        this.bookPrice=bookPrice;
    }
    public String getIsbn()
    {
    	return this.bookIsbn;
    }
    public String getBookAuthor( )
    {
        return this.bookAuthor;
    }
    public String getBookTitle( )
    {
        return this.bookTitle;
    }
	public double getBookPrice( )
	{
        return this.bookPrice;
    }
	//实现接口中的setEntityContext方法
	public void setEntityContext(EntityContext ec)
	{
		try
		{
			Context initial =new InitialContext();
			ds=(DataSource)initial.lookup(jndi);
		}
		catch(NamingException ne)
		{
			throw new EJBException(ne);
		}
	}
    //实现数据的插入
	public String ejbCreate(String isbn,String author,String title,double price) throws CreateException 
	{
        if(bookIsbn==null) 
        {
            throw new CreateException("主键不能为空");
        }
		try	
		{
			String sql = "insert into book values(?,?,?,?)";
			con = ds.getConnection();
			PreparedStatement stmt = con.prepareStatement(sql);
			stmt.setString(1,bookIsbn);
			stmt.setString(2,bookAuthor);
			stmt.setString(3,bookTitle);
			stmt.setDouble(4,bookPrice);
			stmt.executeUpdate();
			stmt.close();
		}
		catch (SQLException e)
		{
			throw new EJBException(e);
		}
		finally
		{
			try	
			{
				if (con!=null)
				{
					con.close();
				}
			}
			catch (SQLException e)
			{
			}
		}
        this.bookIsbn=bookIsbn;
        this.bookAuthor=bookAuthor;
        this.bookTitle=bookTitle;
        this.bookPrice=bookPrice;
		//返回主键值
        return bookIsbn;
    }  
	public void ejbPostCreate(String isbn,String author,String title,double price)
	{
	}
     //实现数据的查找
	public void ejbLoad()
	{
		try
		{
			String sql="select isbn,author,title,price from book where isbn=?";
			con=ds.getConnection();
			PreparedStatement stmt =con.prepareStatement(sql);
			stmt.setString(1,this.bookIsbn);
			ResultSet rset=stmt.executeQuery();
			if(rset.next())
			{
				this.bookAuthor=rset.getString("author");
				this.bookTitle=rset.getString("title");
				this.bookPrice=rset.getDouble("price");
				stmt.close();
			}
			else
			{
				stmt.close();
				throw new NoSuchEntityException("书的Isbn为:"+this.bookIsbn);
			}
		}
		catch (SQLException se)
		{
			throw new EJBException(se);
		}
		finally
		{
			try{
				if(con!=null) 
				{
					con.close();
				}
			}
			catch(SQLException se)
			{
			}
		}
	}
    //实现数据的修改
   public void ejbStore()
   {
		try 
		{
			String sql="update book set author=?,title=?,price=? where isbn=?";
			con=ds.getConnection();
			PreparedStatement stmt =con.prepareStatement(sql);
			stmt.setString(1,this.bookAuthor);
			stmt.setString(2,this.bookTitle);
			stmt.setDouble(3,this.bookPrice);
			stmt.setString(4,this.bookIsbn);
			if(stmt.executeUpdate()!=1)
			{
				stmt.close();
				throw new EJBException("修改异常");
			}
			stmt.close();
		}
		catch (SQLException se)
		{
			throw new EJBException(se);
		}
		finally
		{
			try
			{
				if(con!=null)
				{
					con.close();
				}
			}
			catch(SQLException se)
			{
			}
	   }
	}
    //实现数据的删除
	public void ejbRemove()
	{
		try
		{
			String sql="delete from book where isbn=?";
			con=ds.getConnection();
			PreparedStatement stmt =con.prepareStatement(sql);
			stmt.setString(1,this.bookIsbn);	
			if(stmt.executeUpdate()!=1)
			{
				throw new EJBException("删除异常");
			}
			stmt.close();
		}
		catch (SQLException se)
		{
			throw new EJBException(se);
		}
		finally
		{
			try{
				if(con!=null)
				{
					con.close();
				}
			}
			catch(SQLException se)
			{
			}
		}
	}
    public void unsetEntityContext()
    {
		this.ec=null;
	}  
	public void ejbActivate()
	{
		this.bookIsbn=(String)ctx.getPrimaryKey();
	}
	public void ejbPassivate()
	{
		this.bookIsbn=null;
	}
	public String ejbFindByPrimaryKey(String primarykey) throws FinderException 
	{
		try
		{
			String sql="select isbn from book where isbn=?";
			con = ds.getConnection();
			PreparedStatement stmt =con.prepareStatement(sql);
			stmt.setString(1,primarykey);
			ResultSet rset=stmt.executeQuery();
			if(!rset.next())
			{
				stmt.close();
				throw new ObjectNotFoundException();
			}
			stmt.close();
			return primarykey;

		}
		catch (SQLException se)
		{
			throw new EJBException(se);
		}
		finally
		{
			try{
				if(con!=null)
				{
					con.close();
				}
			}
			catch(SQLException se)
			{
			}
		}
	}
	public Collection ejbFindByPrice(double price) throws FinderException 
	{
		try	
		{
			String sql="select isbn from book where price >?";
			con=ds.getConnection();
			PreparedStatement stmt =con.prepareStatement(sql);
			stmt.setDouble(1,price);
			ResultSet rset=stmt.executeQuery();
			ArrayList booklist=new ArrayList();
			while(rset.next())
			{
				booklist.add(rset.getString("id"));
			}
			stmt.close();
			return booklist;
		}
		catch (SQLException se)
		{
			throw new EJBException(se);
		}
		finally
		{
			try
			{
				if(con!=null)
				{
					con.close();
				}
			}
			catch(SQLException se)
			{
			}
		}
	}
}