Feb
04

JTable Display Long Text With Linebreak & Word Wrap

Today I searched how to properly display a user note with line break and word wrap in a JTable. By default the table was truncating the note display and ignoring the line breaks in the text. After scouring the internet, I found out it is possible to inject a JTextArea into a table cell by implementing TableCellRenderer. It is also possible to control the height and width of the column from inside the renderer. Below is a class that can be used in the JTable to achieve this functionality:

package com.mr.gui;

import java.awt.Component;

import javax.swing.JTable;
import javax.swing.JTextArea;
import javax.swing.table.TableCellRenderer;

/**
 * Setups the table to properly wrap and display notes in the table
 *
 *
 * @author Paul Zepernick
 */
public class TableCellLongTextRenderer extends JTextArea implements TableCellRenderer{

	@Override
	public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
		this.setText((String)value);
        this.setWrapStyleWord(true);
        this.setLineWrap(true);    

        //set the JTextArea to the width of the table column
        setSize(table.getColumnModel().getColumn(column).getWidth(),getPreferredSize().height);
 		if (table.getRowHeight(row) != getPreferredSize().height) {
 			//set the height of the table row to the calculated height of the JTextArea
        	table.setRowHeight(row, getPreferredSize().height);
   		}

		return this;
	}

}

It is applied to the table by doing the following:

	//needs to be set on the appropriate column indicy
	myJTable.getColumnModel().getColumn(0).setCellRenderer(new TableCellLongTextRenderer ());

I found out that by using the TableCellRenderer you an actually inject any Swing component into the table. Cool stuff… I was able to use this to inject a panel with a checkbox and a button. More to come on that later…

Mar
27

Announcing FlatPack 3.2 | Java Delimited / Fixed File API

ObjectLab and Paul Zepernick (me) are proud to announce Flatpack 3.2. Flatpack serves as a Java tool box for writing and reading fixed width and delimited files. It is a very mature API that has been in existence since 2005.

FlatPack is currently used in the Apache Camel project and Apache ActiveMQ just to name a couple.

For those not familiar with FlatPack, I have provided a couple quick examples below. Column names in the flat files can be bound via a header record in the file, or through an XML mapping.

Example of reading a delimited file

    	Parser parser = DefaultParserFactory.getInstance().newDelimitedParser(
                new FileReader("DataFile.txt"),  //txt file or String to parse. Can Take any Reader
                ',', //delimiter
                '"'); //text qualifier

        //obtain DataSet
        DataSet ds = parser.parse();

        while (ds.next()){ //loop through file
            ds.getString("mycolumnName");
        }


Example of reading a fixed width file

	    //Obtain the proper parser for your needs
        Parser parser = DefaultParserFactory.getInstance().newFixedLengthParser(
        		new FileReader("map.fpmap.xml"), //fixed with column map
                new FileReader("DataFile.txt"));  //txt file or String to parse.  Can take any Reader

        //obtain DataSet
        DataSet ds = parser.parse();

        while (ds.next()){ //loop through file
            ds.getString("mycolumnName");
        }

Please check out the FlatPack website for more examples and complete documentation, or download now from Sourceforge.

Jan
13

Problems Executing Java From Cron

Today I searched on a path problem when executing a Java program from Cron. The sh script I was executing ran fine when executing in the shell, but hibernate was failing its startup. It turns out that it was not using the correct version of Java. The path export that normally fires when a user shells in was not present when Cron fired the job.

The solution: export the path and append the path to the correct Java version in the shell script.

export PATH=/jdk1.6.0_16/bin:$PATH

Only took about 30 minutes to figure that out…uggg

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