Long lines in Java Tooltips (or multiline tooltips)
Do you want to show a tooltip with more than one line? Are your tooltips too large to fit in one line? The solution is easier than you think. Tooltips, in Java, accept HTML code:
jcomponent.setToolTipText("HTML tooltip");
It isn't a Firefox, but is very powerful. And, when I said HTML, I also think about CSS. So, you can set your tooltips using this evil cheat:
<html><body> <strong><div style="width: 300px; text-justification: justify;"></strong> Blah Blah Blah (repeat "blah" 100 times) </div> </html></body>
Have you seen automatic line breaks and the justification? Oh, yeah!
BTW, do you remember old days, when you couldn't believe WordPad didn't have justified text? 
Copying file in Java – NIO version
In old days, copying a file in Java wasn't easy: you had to create a array buffer to read from source and write to destination. Now, with NIO from JDK, it's a matter of creating the streams and let the API do the dirty job.
FileChannel src = new FileInputStream(srcFile).getChannel(); FileChannel dst = new FileOutputStream(dstFile).getChannel(); try { dst.transferFrom(src, 0, src.size()); } finally { src.close(); dst.close(); }
Tooltip on JTable cells
This is a easy one (but it is not obvious): how to define tooltips in JTable's cells. Just create a class like this one:
public class ToolTipTable extends JTable { @Override public Component prepareRenderer(TableCellRenderer renderer, int row, int column) { Component c = super.prepareRenderer(renderer, row, column); if (c instanceof JComponent) { JComponent jc = (JComponent) c; jc.setToolTipText((String) getValueAt(row, column)); } return c; } }
This example will set cells' tooltip to its own content. Very useful if you have large contents on small cells.