blogdaoimpl.java

blog 系 统 （基 于 java ）

		final boolean isConnSupplied = (userConn != null);
		Connection conn = null;
		PreparedStatement stmt = null;
		
		try {
			// get the user-specified connection or get a connection from the ResourceManager
			conn = isConnSupplied ? userConn : ResourceManager.getConnection();
		
			System.out.println( "Executing " + SQL_DELETE + " with PK: " + pk );
			stmt = conn.prepareStatement( SQL_DELETE );
			stmt.setInt( 1, pk.getBlogID() );
			int rows = stmt.executeUpdate();
			long t2 = System.currentTimeMillis();
			System.out.println( rows + " rows affected (" + (t2-t1) + " ms)" );
		}
		catch (SQLException _e) {
			_e.printStackTrace();
			throw new BlogDaoException( "SQLException: " + _e.getMessage(), _e );
		}
		catch (Exception _e) {
			_e.printStackTrace();
			throw new BlogDaoException( "Exception: " + _e.getMessage(), _e );
		}
		finally {
			ResourceManager.close(stmt);
			if (!isConnSupplied) {
				ResourceManager.close(conn);
			}
		
		}
		
	}

	/** 
	 * Returns the rows from the Blog table that matches the specified primary-key value.
	 */
	public Blog findByPrimaryKey(BlogPk pk) throws BlogDaoException
	{
		return findByPrimaryKey( pk.getBlogID() );
	}

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

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

	/** 
	 * Returns all rows from the Blog table that match the criteria 'BlogID = :blogID'.
	 */
	public Blog[] findWhereBlogIDEquals(int blogID) throws BlogDaoException
	{
		return findByDynamicSelect( SQL_SELECT + " WHERE BlogID = ? ORDER BY BlogID", new Object[] {  new Integer(blogID) } );
	}

	/** 
	 * Returns all rows from the Blog table that match the criteria 'Username = :username'.
	 */
	public Blog[] findWhereUsernameEquals(String username) throws BlogDaoException
	{
		return findByDynamicSelect( SQL_SELECT + " WHERE Username = ? ORDER BY Username", new Object[] { username } );
	}

	/** 
	 * Returns all rows from the Blog table that match the criteria 'Password = :password'.
	 */
	public Blog[] findWherePasswordEquals(String password) throws BlogDaoException
	{
		return findByDynamicSelect( SQL_SELECT + " WHERE Password = ? ORDER BY Password", new Object[] { password } );
	}

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

	/** 
	 * Returns all rows from the Blog table that match the criteria 'Description = :description'.
	 */
	public Blog[] findWhereDescriptionEquals(String description) throws BlogDaoException
	{
		return findByDynamicSelect( SQL_SELECT + " WHERE Description = ? ORDER BY Description", new Object[] { description } );
	}

	/** 
	 * Returns all rows from the Blog table that match the criteria 'Email = :email'.
	 */
	public Blog[] findWhereEmailEquals(String email) throws BlogDaoException
	{
		return findByDynamicSelect( SQL_SELECT + " WHERE Email = ? ORDER BY Email", new Object[] { email } );
	}

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

	/**
	 * Method 'BlogDaoImpl'
	 * 
	 * @param userConn
	 */
	public BlogDaoImpl(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..Blog";
	}

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

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

	/** 
	 * Populates a DTO with data from a ResultSet
	 */
	protected void populateDto(Blog dto, ResultSet rs) throws SQLException
	{
		dto.setBlogID( rs.getInt( COLUMN_BLOG_I_D ) );
		dto.setUsername( rs.getString( COLUMN_USERNAME ) );
		dto.setPassword( rs.getString( COLUMN_PASSWORD ) );
		dto.setSubject( rs.getString( COLUMN_SUBJECT ) );
		dto.setDescription( rs.getString( COLUMN_DESCRIPTION ) );
		dto.setEmail( rs.getString( COLUMN_EMAIL ) );
	}

	/** 
	 * Returns all rows from the Blog table that match the specified arbitrary SQL statement
	 */
	public Blog[] findByDynamicSelect(String sql, Object[] sqlParams) throws BlogDaoException
	{
		// 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 BlogDaoException( "SQLException: " + _e.getMessage(), _e );
		}
		catch (Exception _e) {
			_e.printStackTrace();
			throw new BlogDaoException( "Exception: " + _e.getMessage(), _e );
		}
		finally {
			ResourceManager.close(rs);
			ResourceManager.close(stmt);
			if (!isConnSupplied) {
				ResourceManager.close(conn);
			}
		
		}
		
	}

	/** 
	 * Returns all rows from the Blog table that match the specified arbitrary SQL statement
	 */
	public Blog[] findByDynamicWhere(String sql, Object[] sqlParams) throws BlogDaoException
	{
		// 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 BlogDaoException( "SQLException: " + _e.getMessage(), _e );
		}
		catch (Exception _e) {
			_e.printStackTrace();
			throw new BlogDaoException( "Exception: " + _e.getMessage(), _e );
		}
		finally {
			ResourceManager.close(rs);
			ResourceManager.close(stmt);
			if (!isConnSupplied) {
				ResourceManager.close(conn);
			}
		
		}
		
	}

}