Here you can find the source of adjustColumnPreferredWidths(JTable table)
http://niravjavadeveloper.blogspot.com/2011/05/resize-jtable-columns.html
public static void adjustColumnPreferredWidths(JTable table)
//package com.java2s; import java.awt.Component; import javax.swing.*; import javax.swing.table.*; public class Main { /**//from ww w. j a v a 2s . co m * http://niravjavadeveloper.blogspot.com/2011/05/resize-jtable-columns.html */ public static void adjustColumnPreferredWidths(JTable table) { // strategy - get max width for cells in column and // make that the preferred width TableColumnModel columnModel = table.getColumnModel(); for (int col = 0; col < table.getColumnCount(); col++) { int maxwidth = 0; for (int row = 0; row < table.getRowCount(); row++) { TableCellRenderer rend = table.getCellRenderer(row, col); Object value = table.getValueAt(row, col) + " "; Component comp = rend.getTableCellRendererComponent(table, value, false, false, row, col); maxwidth = Math.max(comp.getPreferredSize().width, maxwidth); } TableColumn column = columnModel.getColumn(col); column.setPreferredWidth(maxwidth); } } }