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POAdd column to JTable that has some rows before adding
 

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  1. POAdd column to JTable that has some rows before adding
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    <p>I have a <code>JTable</code> that contains 4 columns and for example 10 rows. I want to add a new column and put the maximum value for each row in that. </p> <p>Here is the function that I use to compute the maximum and put them into the new column:</p> <pre><code>private void jFindmaximumActionPerformed(java.awt.event.ActionEvent evt) { DefaultTableModel model = (DefaultTableModel)jMYtable.getModel(); TableColumn col = new TableColumn(model.getColumnCount()); String headerLabel = "Maximum"; col.setHeaderValue(headerLabel); jMYtable.addColumn(col); model.addColumn(headerLabel.toString(), new Object [0]); double[] MAX = new double[ndata[0].length]; for(int i = 0; i &lt; ndata[0].length; i++){ MAX[i] = ndata[i][0]; for(int j = 0 ; j &lt; ndata.length; j ++){ if(ndata[j][i] &gt; MAX[i]){ MAX[i] = ndata[j][i]; } } model.setValueAt(MAX[i],i,4); } jMYtable.revalidate(); } </code></pre> <p>If my table does not have any row when I call this method the new column is added and shows up on the interface. However, when I populate my table with 10 rows and call this action, table is not acting properly: </p> <ol> <li>There is a gui redraw problem where the new column will show only after mouse goes on the <code>jtable</code>; and </li> <li>The new column does not have any data.</li> </ol> <p>Please help.</p>
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USAndrew Thompson
    1. USMorteza
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
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      1. PTAnswer
    1. VO
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      1. POAdd column to JTable that has some rows before adding
      1. This table or related slice is empty.
      1. VTApproveEditSuggestion
    1. COI find out that new column does not have any rows, this make problem in rendering of jtable, but how can I add rows for only this column or I need to remove all rows and again insert them into the jtable?
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      1. POAdd column to JTable that has some rows before adding
      1. USMorteza
    2. COcode should be works, jMYtable.revalidate(); is about relayout, quite useless and very hard event called ndata[0].length times
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      1. POAdd column to JTable that has some rows before adding
      1. USmKorbel
    3. COHow can I insert rows for new column?
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      1. POAdd column to JTable that has some rows before adding
      1. USMorteza
 

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