How to change the text color of a column of a Jtable

Question

I have a form for payment of installments, and this form has a table where I show both the installments paid and those that should still be paid.

To popular this JTable, I make a query in the database and bring the necessary information.

public void preencherParcelas(String SQL) {
    ArrayList dados = new ArrayList();
    String[] colunas = new String[]{"Data Pagamento", "Valor Parcela", "Status Pagamento"};
    conecta.conexao();
    conecta.executaSQL(SQL);
    String status;
    try {
        conecta.rs.first();
        dataVenda = conecta.rs.getString("data_venda");
        idParcelamento = conecta.rs.getInt("id_parcelamento");
        do {

            if (conecta.rs.getInt("status_pagamento") == 0) {
                status = "PAGAMENTO PENDENTE";
            } else {
                status = "PAGAMENTO EFETUADO";
            }

            dados.add(new Object[]{conecta.rs.getString("data_pagamento"), "R$ " + conecta.rs.getString("valor_parcelas"), status});

        } while (conecta.rs.next());
} catch (SQLException ex) {

        JOptionPane.showMessageDialog(rootPane, "ERRO AO LOCALIZAR PARCELAS" + ex);

    }

ModeloTabela modelo = new ModeloTabela(dados, colunas);

    jTableInformaVencimentos.setModel(modelo);
    jTableInformaVencimentos.getColumnModel().getColumn(0).setPreferredWidth(150);
    jTableInformaVencimentos.getColumnModel().getColumn(0).setResizable(false);

    jTableInformaVencimentos.setModel(modelo);
    jTableInformaVencimentos.getColumnModel().getColumn(1).setPreferredWidth(150);
    jTableInformaVencimentos.getColumnModel().getColumn(1).setResizable(false);

    jTableInformaVencimentos.setModel(modelo);
    jTableInformaVencimentos.getColumnModel().getColumn(2).setPreferredWidth(150);
    jTableInformaVencimentos.getColumnModel().getColumn(2).setResizable(false);

    jTableInformaVencimentos.getTableHeader().setReorderingAllowed(false);
    jTableInformaVencimentos.setAutoResizeMode(jTableInformaVencimentos.AUTO_RESIZE_ALL_COLUMNS);
    jTableInformaVencimentos.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    conecta.desconecta();

Model used in the Table

    public class ModeloTabela extends AbstractTableModel{

    private ArrayList linhas = null;
    private String[] colunas = null;

    public ModeloTabela(ArrayList lin, String[] col){
        setLinhas(lin);
        setColunas(col);

    }
    public ArrayList getLinhas(){
        return linhas;
    }

    public void setLinhas(ArrayList dados){
        linhas = dados;
    }

    public String[] getColunas(){
        return colunas;
    }

    public void setColunas (String[] nomes){
        colunas = nomes;
    }

    public int getColumnCount(){
        //retorna a quantidade de colunas(conta a quantidade e retorna)
        return colunas.length;
    }

    public int getRowCount(){
        //retorna o tamanho do array(quantos letras tem)
        return linhas.size();
    }

    public String getColumnName(int numCol){
        return colunas[numCol];
    }

    public Object getValueAt(int numLin, int numCol){
        Object[] linha = (Object[])getLinhas().get(numLin);
        return linha[numCol];
    }

}

I’d like to know when a "PAYMENT MADE" that one String stay in preferred red color. How can I do this?

Answer 1

You need to change the way the JTable render the cell on the screen, and for that, use the class DefaultTableCellRenderer, or create your own Jump. The simplest way is to use the cited default class:

DefaultTableCellRenderer renderer = new DefaultTableCellRenderer() {
    @Override
    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
        Component c = super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column); 

        String str = (String) value;
        if ("PAGAMENTO EFETUADO".equals(str)) {
            c.setForeground(Color.RED);
        } else {
            c.setForeground(Color.BLACK);
        }
        return c;
    }
};

And then apply the right column to the desired column, in your case, column 2:

jTableInformaVencimentos.getColumnModel().getColumn(2).setCellRenderer(renderer);

Remembering that this Renderer, if applied as default of the JTable, will make the color change for all columns, so I only applied the informed column.

If you want to learn more about renderers, you can access the official tutorial of oracle.