Class TableAppender

  • All Implemented Interfaces:
    Flushable, Appendable

    public class TableAppender
    extends Object
    implements Flushable
    An Appendable which formats the text as a table suitable for displaying in devices using a monospaced font. Columns are separated by tabulations ('\t') and rows are separated by line or paragraph separators. The content of every table cells are stored in memory until the flush() method is invoked. When invoked, flush() copies the cell contents to the underlying stream or buffer while replacing tabulations by some amount of spaces and drawing borders. The exact number of spaces is computed from the cell widths.

    For example, the following code:

    TableAppender table = new TableAppender(System.out);
    table.nextLine('═');
    table.append("English\tFrench\tr.e.d.\n");
    table.nextLine('-');
    table.append("Mercury\tMercure\t0.382\n")
         .append("Venus\tVénus\t0.949\n")
         .append("Earth\tTerre\t1.00\n")
         .append("Mars\tMars\t0.532\n");
    table.nextLine('═');
    table.flush();
    produces the following output:
    ╔═════════╤═════════╤════════╗
    ║ English │ French  │ r.e.d. ║
    ╟─────────┼─────────┼────────╢
    ║ Mercury │ Mercure │ 0.382  ║
    ║ Venus   │ Vénus   │ 0.949  ║
    ║ Earth   │ Terre   │ 1.00   ║
    ║ Mars    │ Mars    │ 0.532  ║
    ╚═════════╧═════════╧════════╝
    Since:
    0.3
    See Also:
    Tree­Table­Format

    Defined in the sis-utility module

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static byte ALIGN_CENTER
      A possible value for cell alignment.
      static byte ALIGN_LEFT
      A possible value for cell alignment.
      static byte ALIGN_RIGHT
      A possible value for cell alignment.
      protected Appendable out
      The underlying character output stream or buffer.
    • Constructor Summary

      Constructors 
      Constructor Description
      TableAppender()
      Creates a new table formatter writing in an internal buffer with a default column separator.
      TableAppender​(Appendable out)
      Creates a new table formatter writing in the given output with a default column separator.
      TableAppender​(Appendable out, String separator)
      Creates a new table formatter writing in the given output with the specified column separator.
      TableAppender​(Appendable out, String leftBorder, String separator, String rightBorder)
      Creates a new table formatter writing in the given output with the specified column separator and border.
      TableAppender​(String separator)
      Creates a new table formatter writing in an internal buffer with the specified column separator.
    • Field Detail

      • ALIGN_LEFT

        public static final byte ALIGN_LEFT
        A possible value for cell alignment. This specifies that the text is aligned to the left indent and extra whitespace should be placed on the right.
        See Also:
        Constant Field Values
      • ALIGN_CENTER

        public static final byte ALIGN_CENTER
        A possible value for cell alignment. This specifies that the text is aligned to the center and extra whitespace should be placed equally on the left and right.
        See Also:
        Constant Field Values
      • ALIGN_RIGHT

        public static final byte ALIGN_RIGHT
        A possible value for cell alignment. This specifies that the text is aligned to the right indent and extra whitespace should be placed on the left.
        See Also:
        Constant Field Values
      • out

        protected final Appendable out
        The underlying character output stream or buffer.
    • Constructor Detail

      • TableAppender

        public TableAppender()
        Creates a new table formatter writing in an internal buffer with a default column separator. The default is a vertical double line for the left and right table borders, and a single line between the columns.
      • TableAppender

        public TableAppender​(String separator)
        Creates a new table formatter writing in an internal buffer with the specified column separator.
        Parameters:
        separator - string to write between columns.
      • TableAppender

        public TableAppender​(Appendable out)
        Creates a new table formatter writing in the given output with a default column separator. The default is a vertical double line for the left and right table borders, and a single line between the columns.
        Parameters:
        out - the underlying stream or buffer to write to.
      • TableAppender

        public TableAppender​(Appendable out,
                             String separator)
        Creates a new table formatter writing in the given output with the specified column separator.
        Parameters:
        out - the underlying stream or buffer to write to.
        separator - string to write between columns.
      • TableAppender

        public TableAppender​(Appendable out,
                             String leftBorder,
                             String separator,
                             String rightBorder)
        Creates a new table formatter writing in the given output with the specified column separator and border.
        Parameters:
        out - the underlying stream or buffer to write to.
        left­Border - string to write on the left side of the table.
        separator - string to write between columns.
        right­Border - string to write on the right side of the table.
        Since:
        0.8
    • Method Detail

      • isMultiLinesCells

        public boolean isMultiLinesCells()
        Returns true if EOL characters are used for line feeds inside current cells.
        Returns:
        true if EOL characters are to be write inside the cell.
      • setMultiLinesCells

        public void setMultiLinesCells​(boolean multiLines)
        Sets the desired behavior for EOL and tabulations characters.
        • If true, then tabulations, line and paragraph separator characters are copied into the current cell. Subsequent writing operations will continue inside the same cell.
        • If false, then tabulations move to next column and EOL move to the first cell of next row (i.e. tabulation and EOL are equivalent to next­Column() and next­Line() calls respectively).
        The default value is false.
        Parameters:
        multi­Lines - true true if EOL are used for line feeds inside current cells, or false if EOL move to the next row.
      • getCellAlignment

        public byte getCellAlignment()
        Returns the alignment of the text inside the current cell. The default value is ALIGN_LEFT.
        Returns:
        current cell alignment as one of the ALIGN_LEFT, ALIGN_RIGHT or ALIGN_CENTER constants.
      • setCellAlignment

        public void setCellAlignment​(byte alignment)
        Sets the alignment of the text inside the current cell. The alignments of any cell written prior this method call are left unchanged. The new alignment will apply to the next cells too until this set­Cell­Alignment(…) method is invoked again with a different value.

        If this method is never invoked, then the default alignment is ALIGN_LEFT.

        Parameters:
        alignment - the new cell alignment as one of the ALIGN_LEFT, ALIGN_RIGHT or ALIGN_CENTER constants.
      • getLineSeparator

        public String getLineSeparator()
        Returns the line separator between table rows. This is the first line separator found in the text formatted as a table, or the system default if no line separator was found in the text to format.
        Returns:
        the line separator between table rows.
        Since:
        1.0
      • getRowCount

        public int getRowCount()
        Returns the number of rows in this table. This count is reset to 0 by flush().
        Returns:
        the number of rows in this table.
      • getColumnCount

        public int getColumnCount()
        Returns the number of columns in this table.
        Returns:
        the number of columns in this table.
      • append

        public TableAppender append​(CharSequence sequence)
        Appends the specified character sequence.
        Specified by:
        append in interface Appendable
        Parameters:
        sequence - the character sequence to append, or null.
        Returns:
        a reference to this Appendable.
      • append

        public TableAppender append​(CharSequence sequence,
                                    int start,
                                    int end)
        Writes a portion of a character sequence. Tabulations and line separators are interpreted as by append(char).
        Specified by:
        append in interface Appendable
        Parameters:
        sequence - the character sequence to be written.
        start - index from which to start reading characters.
        end - index of the character following the last character to read.
        Returns:
        this.
      • appendHorizontalSeparator

        public void appendHorizontalSeparator()
        Writes an horizontal separator using the '─' character.
        See Also:
        next­Line(char)
      • nextColumn

        public void nextColumn()
        Moves one column to the right. The subsequent writing operations will occur in a new cell on the same row.
      • nextColumn

        public void nextColumn​(char fill)
        Moves one column to the right, filling remaining space with the given character. The subsequent writing operations will occur in a new cell on the same row.

        Calling next­Column('*') from the first character in a cell is a convenient way to put a pad value in this cell.

        Parameters:
        fill - character filling the cell (default to whitespace).
      • nextLine

        public void nextLine()
        Moves to the first column on the next row. The subsequent writing operations will occur on a new row.
      • nextLine

        public void nextLine​(char fill)
        Moves to the first column on the next row, filling every remaining cell in the current row with the specified character. The subsequent writing operations will occur on a new row.

        Calling next­Line('-') or next­Line('═') from the first column of a row is a convenient way to fill this row with a line separator.

        Parameters:
        fill - character filling the rest of the line (default to whitespace). This character may be use as a row separator.
        See Also:
        append­Horizontal­Separator()
      • flush

        public void flush()
                   throws IOException
        Flushes the table content to the underlying stream or buffer. This method should not be called before the table is completed (otherwise, columns may have the wrong width).
        Specified by:
        flush in interface Flushable
        Throws:
        IOException - if an output operation failed.
      • toString

        public String toString()
        Returns the content of this Table­Appender as a string if possible.
        • If this Table­Appender has been created without explicit Appendable, then this method always returns the current table content formatted as a string.
        • Otherwise, if out implements Char­Sequence or is directly or indirectly a wrapper around a Char­Sequence, returns its to­String() representation. The string will contain this table content only if flush() has been invoked prior this to­String() method.
        • Otherwise returns the localized "Unavailable content" string.
        Returns:
        the content of this Appendable, or a localized message for unavailable content.
        See Also:
        IO​.content(Appendable)