Rendering of table cells is handled by instances of TableCellRenderer. By default JTable uses a DefaultTableCellRenderer to render all of its cells.
\nTo control the number of decimal places used we just need to subclass DefaultTableCellRenderer and format the cell double value before passing the (formatted) value to to the parent (DefaultTableCellRenderer) class.
\nTo get the table to use that class we tell the JTable to use it for a given column.<\/p>\n
Following example illustrates what is required.<\/p>\n
\r\npackage com.learnjava.swing.table;\r\n\r\nimport java.awt.*;\r\nimport java.text.DecimalFormat;\r\nimport javax.swing.*;\r\nimport javax.swing.table.*;\r\n\r\npublic class DecimalPlacesInTable extends JFrame {\r\n\tpublic static void main( String[] args ) {\r\n\t\tDecimalPlacesInTable frame = new DecimalPlacesInTable();\r\n\t\tframe.setDefaultCloseOperation( EXIT_ON_CLOSE );\r\n\t\tframe.pack();\r\n\t\tframe.setVisible( true );\r\n\t}\r\n\r\n\tpublic DecimalPlacesInTable() {\r\n\t\tObject[] columnNames = { "A", "B", "C" };\r\n\t\tObject[][] data = {\r\n\t\t\t\t{ "abc", new Double( 850.503 ), 5 },\r\n\t\t\t\t{ "def", new Double( 36.23254 ), 6 },\r\n\t\t\t\t{ "ghi", new Double( 8.3 ), 7 },\r\n\t\t\t\t{ "jkl", new Double( 246.0943 ), 23 }};\r\n\r\n\t\tJTable table = new JTable(data, columnNames);\r\n\r\n \/\/ Tell the table what to use to render our column of doubles\r\n\r\n\t\ttable.getColumnModel().getColumn(1).setCellRenderer(\r\n\t\t\tnew DecimalFormatRenderer() );\r\n\t\tgetContentPane().add(new JScrollPane(table));\r\n\t}\r\n\r\n \/**\r\n Here is our class to handle the formatting of the double values\r\n *\/\r\n\r\n\tstatic class DecimalFormatRenderer extends DefaultTableCellRenderer {\r\n\t\tprivate static final DecimalFormat formatter = new DecimalFormat( "#.00" );\r\n\r\n\t\tpublic Component getTableCellRendererComponent(\r\n\t\t\tJTable table, Object value, boolean isSelected,\r\n\t\t\tboolean hasFocus, int row, int column) {\r\n\r\n\t\t\t\/\/ First format the cell value as required\r\n\r\n\t\t\tvalue = formatter.format((Number)value);\r\n\r\n \/\/ And pass it on to parent class\r\n\r\n\t\t\treturn super.getTableCellRendererComponent(\r\n\t\t\t\ttable, value, isSelected, hasFocus, row, column );\r\n\t\t}\r\n\t}\r\n}\r\n\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"Rendering of table cells is handled by instances of TableCellRenderer. By default JTable uses a DefaultTableCellRenderer to render all of its cells. To control the number of decimal places used we just need to subclass DefaultTableCellRenderer and format the cell double value before passing the (formatted) value to to the parent (DefaultTableCellRenderer) class. To get…<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"jetpack_publicize_message":"","jetpack_is_tweetstorm":false,"jetpack_publicize_feature_enabled":true,"jetpack_social_options":[]},"categories":[4,15],"tags":[87,88,85,86],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p6Yyl2-4Q","jetpack-related-posts":[{"id":251,"url":"https:\/\/learn-java-by-example.com\/java\/add-checkbox-items-jlist\/","url_meta":{"origin":300,"position":0},"title":"How do add a checkbox to items in a JList?","date":"June 30, 2015","format":false,"excerpt":"We often get asked about how to implement a list of checkboxes using Swing. Using a JList filled with JCheckbox's seems the obvious solution, however JList does not support cell editors so this does not work. 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