essaydaoimpl.java

blog 系 统 （基 于 java ）

			conn = isConnSupplied ? userConn : ResourceManager.getConnection();
		
			System.out.println( "Executing " + SQL_DELETE + " with PK: " + pk );
			stmt = conn.prepareStatement( SQL_DELETE );
			stmt.setInt( 1, pk.getEssayID() );
			int rows = stmt.executeUpdate();
			long t2 = System.currentTimeMillis();
			System.out.println( rows + " rows affected (" + (t2-t1) + " ms)" );
		}
		catch (SQLException _e) {
			_e.printStackTrace();
			throw new EssayDaoException( "SQLException: " + _e.getMessage(), _e );
		}
		catch (Exception _e) {
			_e.printStackTrace();
			throw new EssayDaoException( "Exception: " + _e.getMessage(), _e );
		}
		finally {
			ResourceManager.close(stmt);
			if (!isConnSupplied) {
				ResourceManager.close(conn);
			}
		
		}
		
	}

	/** 
	 * Returns the rows from the Essay table that matches the specified primary-key value.
	 */
	public Essay findByPrimaryKey(EssayPk pk) throws EssayDaoException
	{
		return findByPrimaryKey( pk.getEssayID() );
	}

	/** 
	 * Returns all rows from the Essay table that match the criteria ''.
	 */
	public Essay[] findAll() throws EssayDaoException
	{
		return findByDynamicSelect( SQL_SELECT + " ORDER BY EssayID", null );
	}

	/** 
	 * Returns all rows from the Essay table that match the criteria 'EssayID = :essayID'.
	 */
	public Essay findByPrimaryKey(int essayID) throws EssayDaoException
	{
		Essay ret[] = findByDynamicSelect( SQL_SELECT + " WHERE EssayID = ?", new Object[] {  new Integer(essayID) } );
		return ret.length==0 ? null : ret[0];
	}

	/** 
	 * Returns all rows from the Essay table that match the criteria 'CategoryID = :categoryID'.
	 */
	public Essay[] findByCategory(int categoryID) throws EssayDaoException
	{
		return findByDynamicSelect( SQL_SELECT + " WHERE CategoryID = ?", new Object[] {  new Integer(categoryID) } );
	}

	/** 
	 * Returns all rows from the Essay table that match the criteria 'CategoryID = :categoryID'.
	 */
	public Essay[] findWhereCategoryIDEquals(int categoryID) throws EssayDaoException
	{
		return findByDynamicSelect( SQL_SELECT + " WHERE CategoryID = ? ORDER BY CategoryID", new Object[] {  new Integer(categoryID) } );
	}

	/** 
	 * Returns all rows from the Essay table that match the criteria 'EssayID = :essayID'.
	 */
	public Essay[] findWhereEssayIDEquals(int essayID) throws EssayDaoException
	{
		return findByDynamicSelect( SQL_SELECT + " WHERE EssayID = ? ORDER BY EssayID", new Object[] {  new Integer(essayID) } );
	}

	/** 
	 * Returns all rows from the Essay table that match the criteria 'Subject = :subject'.
	 */
	public Essay[] findWhereSubjectEquals(String subject) throws EssayDaoException
	{
		return findByDynamicSelect( SQL_SELECT + " WHERE Subject = ? ORDER BY Subject", new Object[] { subject } );
	}

	/** 
	 * Returns all rows from the Essay table that match the criteria 'Content = :content'.
	 */
	public Essay[] findWhereContentEquals(String content) throws EssayDaoException
	{
		return findByDynamicSelect( SQL_SELECT + " WHERE Content = ? ORDER BY Content", new Object[] { content } );
	}

	/** 
	 * Returns all rows from the Essay table that match the criteria 'PublishTime = :publishTime'.
	 */
	public Essay[] findWherePublishTimeEquals(Date publishTime) throws EssayDaoException
	{
		return findByDynamicSelect( SQL_SELECT + " WHERE PublishTime = ? ORDER BY PublishTime", new Object[] { publishTime==null ? null : new java.sql.Timestamp( publishTime.getTime() ) } );
	}

	/**
	 * Method 'EssayDaoImpl'
	 * 
	 */
	public EssayDaoImpl()
	{
	}

	/**
	 * Method 'EssayDaoImpl'
	 * 
	 * @param userConn
	 */
	public EssayDaoImpl(final java.sql.Connection userConn)
	{
		this.userConn = userConn;
	}

	/** 
	 * Sets the value of maxRows
	 */
	public void setMaxRows(int maxRows)
	{
		this.maxRows = maxRows;
	}

	/** 
	 * Gets the value of maxRows
	 */
	public int getMaxRows()
	{
		return maxRows;
	}

	/**
	 * Method 'getTableName'
	 * 
	 * @return String
	 */
	public String getTableName()
	{
		return "MyBlog..Essay";
	}

	/** 
	 * Fetches a single row from the result set
	 */
	protected Essay fetchSingleResult(ResultSet rs) throws SQLException
	{
		if (rs.next()) {
			Essay dto = new Essay();
			populateDto( dto, rs);
			return dto;
		} else {
			return null;
		}
		
	}

	/** 
	 * Fetches multiple rows from the result set
	 */
	protected Essay[] fetchMultiResults(ResultSet rs) throws SQLException
	{
		Collection resultList = new ArrayList();
		while (rs.next()) {
			Essay dto = new Essay();
			populateDto( dto, rs);
			resultList.add( dto );
		}
		
		Essay ret[] = new Essay[ resultList.size() ];
		resultList.toArray( ret );
		return ret;
	}

	/** 
	 * Populates a DTO with data from a ResultSet
	 */
	protected void populateDto(Essay dto, ResultSet rs) throws SQLException
	{
		dto.setCategoryID( rs.getInt( COLUMN_CATEGORY_I_D ) );
		if (rs.wasNull()) {
			dto.setCategoryIDNull( true );
		}
		
		dto.setEssayID( rs.getInt( COLUMN_ESSAY_I_D ) );
		dto.setSubject( rs.getString( COLUMN_SUBJECT ) );
		dto.setContent( rs.getString( COLUMN_CONTENT ) );
		dto.setPublishTime( rs.getTimestamp(COLUMN_PUBLISH_TIME ) );
	}

	/** 
	 * Returns all rows from the Essay table that match the specified arbitrary SQL statement
	 */
	public Essay[] findByDynamicSelect(String sql, Object[] sqlParams) throws EssayDaoException
	{
		// declare variables
		final boolean isConnSupplied = (userConn != null);
		Connection conn = null;
		PreparedStatement stmt = null;
		ResultSet rs = null;
		
		try {
			// get the user-specified connection or get a connection from the ResourceManager
			conn = isConnSupplied ? userConn : ResourceManager.getConnection();
		
			// construct the SQL statement
			final String SQL = sql;
		
		
			System.out.println( "Executing " + SQL );
			// prepare statement
			stmt = conn.prepareStatement( SQL );
			stmt.setMaxRows( maxRows );
		
			// bind parameters
			for (int i=0; sqlParams!=null && i<sqlParams.length; i++ ) {
				stmt.setObject( i+1, sqlParams[i] );
			}
		
		
			rs = stmt.executeQuery();
		
			// fetch the results
			return fetchMultiResults(rs);
		}
		catch (SQLException _e) {
			_e.printStackTrace();
			throw new EssayDaoException( "SQLException: " + _e.getMessage(), _e );
		}
		catch (Exception _e) {
			_e.printStackTrace();
			throw new EssayDaoException( "Exception: " + _e.getMessage(), _e );
		}
		finally {
			ResourceManager.close(rs);
			ResourceManager.close(stmt);
			if (!isConnSupplied) {
				ResourceManager.close(conn);
			}
		
		}
		
	}

	/** 
	 * Returns all rows from the Essay table that match the specified arbitrary SQL statement
	 */
	public Essay[] findByDynamicWhere(String sql, Object[] sqlParams) throws EssayDaoException
	{
		// declare variables
		final boolean isConnSupplied = (userConn != null);
		Connection conn = null;
		PreparedStatement stmt = null;
		ResultSet rs = null;
		
		try {
			// get the user-specified connection or get a connection from the ResourceManager
			conn = isConnSupplied ? userConn : ResourceManager.getConnection();
		
			// construct the SQL statement
			final String SQL = SQL_SELECT + " WHERE " + sql;
		
		
			System.out.println( "Executing " + SQL );
			// prepare statement
			stmt = conn.prepareStatement( SQL );
			stmt.setMaxRows( maxRows );
		
			// bind parameters
			for (int i=0; sqlParams!=null && i<sqlParams.length; i++ ) {
				stmt.setObject( i+1, sqlParams[i] );
			}
		
		
			rs = stmt.executeQuery();
		
			// fetch the results
			return fetchMultiResults(rs);
		}
		catch (SQLException _e) {
			_e.printStackTrace();
			throw new EssayDaoException( "SQLException: " + _e.getMessage(), _e );
		}
		catch (Exception _e) {
			_e.printStackTrace();
			throw new EssayDaoException( "Exception: " + _e.getMessage(), _e );
		}
		finally {
			ResourceManager.close(rs);
			ResourceManager.close(stmt);
			if (!isConnSupplied) {
				ResourceManager.close(conn);
			}
		
		}
		
	}

}