A simple quick and dirty tab printer written in java

TabPrinter.java

import java.io.IOException;
import java.util.Vector;

/**
 * Utility class to print pretty tables in a console
 */
public class TabPrinter {
	
	private int num_col = 0;
	private String[] titles = null;
	private Vector<String[]> tab = null;

	/**
	 * Constructor
	 * @param column_titles array of columns names
	 */
	public TabPrinter(String[] column_titles) {
		this.titles = column_titles;
		num_col = titles.length;
		tab = new Vector<String[]>();
	}

	/**
	 * @return The columns number
	 */
	public int getColumnsNumber() {
		return num_col;
	}
	
	/**
	 * @return Rows number
	 */
	public int getRowsNumber() {
		return tab.size();
	}
	
	/**
	 * Add a row to the table
	 * @param line Row to add
	 */
	public void addRow(String[] line) {
		tab.add(line);
	}
	
	/**
	 * Change an element's value
	 * @param element The value
	 * @param column Column of the element
	 * @param row Row of the element
	 */
	public void setElement(String element, int column, int row) {
		if(column >= num_col)
			throw new IndexOutOfBoundsException("Tab has only " + num_col + " columns");
		String[] rowLine;
		if(row >= tab.size())
		{
			rowLine = new String[num_col];
			for(int i = 0; i < rowLine.length; i++)
				rowLine[i] = "";
			addRow(rowLine);
		}
		else
			rowLine = tab.get(row);
		rowLine[column] = element;
	}
	
	/**
	 * Remove a line
	 * @param index The row number
	 */
	public void removeLine(int index) {
		tab.remove(index);
	}
	
	/**
	 * Calculate the column width
	 * @param columnIndex column index
	 * @return The column width in characters
	 */
	private int getColumnWidth(int columnIndex) {
		if(columnIndex >= num_col)
			throw new IndexOutOfBoundsException("Tab has only " + num_col + " columns");
		
		int width = titles[columnIndex].length();
		for (String[] r : tab)
		{
			if(r[columnIndex].length() > width)
				width = r[columnIndex].length();
		}
		return width;
	}
	
	/**
	 * Print a line separation ("----")
	 * @param columnWidth The array of columns width
	 * @throws IOException
	 */
	private void printLineSeparation(int[] columnWidth) throws IOException{
		System.out.print("+");
		for(int i = 0; i < num_col; i++)
		{
			for (int j = 0; j < columnWidth[i]+2; j++)
				System.out.print("-");
			System.out.print("+");
		}
		System.out.println("");

	}

	/**
	 * Print a lines
	 * @param line Lines to print
	 * @param columnWidth Array of column width
	 * @throws IOException
	 */
	private void printLine(String[] line, int[] columnWidth) throws IOException{
		System.out.print("|");
		for(int i = 0; i < num_col; i++)
		{
			System.out.print(" " + line[i] + " ");
			for(int j = 0 ; j < (columnWidth[i] - line[i].length()); j++)
				System.out.print(" ");
			System.out.print("|");
		}
		System.out.println("");
	}
	
	/**
	 * Print the table
	 * @throws IOException
	 */
	public void print() throws IOException {
		int[] col_width = new int[num_col];
		for (int i = 0; i < num_col; i++)
		{
			col_width[i] = getColumnWidth(i);
		}
		
		printLineSeparation(col_width);
		printLine(titles, col_width);
		printLineSeparation(col_width);
		for(String[] r : tab)
		{
			printLine(r, col_width);
			printLineSeparation(col_width);
		}
	}
}