Line Wrapping Cell Renderer - Java - swing

Question

I am having trouble implementing a custom cell renderer which will wrap message content when it extends past one line in length. The following is what I have:
public class MessageTable extends JTable
{
private static MessageTable messageTable;
private DefaultTableModel model = new DefaultTableModel();
private String[] emptyData = {};
private TreeMap<Integer, String> messages = null;
public class LineWrapCellRenderer 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);
this.setBackground(Color.YELLOW);
int fontHeight = this.getFontMetrics(this.getFont()).getHeight();
int textLength = this.getText().length();
int lines = textLength / this.getColumns() +1;//+1, because we need at least 1 row.
int height = fontHeight * lines;
table.setRowHeight(row, height);
return this;
}
}
public MessageTable()
{
super();
messageTable = this;
this.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
model.addColumn("Message Number", emptyData);
model.addColumn("Message Content", emptyData);
this.setModel(model);
this.setFont(MappingView.theFont);
this.setDefaultRenderer(String.class, new LineWrapCellRenderer());
}
/**
* Set the current messages.
* #param messages
*/
public void setCurrentMessages(TreeMap<Integer, String> messages)
{
clearCurrentMessages();
this.messages = messages;
if (messages != null)
{
for (Integer key : messages.keySet())
{
String[] row = { key.toString(), messages.get(key).toString() };
model.addRow(row);
}
}
}
For some reason, the LineWrapCellRenderer is never used and the rows only ever contain one line of text.
What am I doing wrong?

Answer 1

Your cellrenderer is not used because the default table model returns Object.class for any column (it does not override AbstractTableModel's implementation):
public Class<?> getColumnClass(int columnIndex) {
return Object.class;
}
So either override the method yourself for the model or assign the renderer to Object.class.