Displaying a jTable inside another jTable // JTable cellRenderer

1// We declare the variables where we'll store our data
2// First an array Object which will be our main table
3Object[][] data = null;
4// We declare an Array String to hold the name of the main table columns
5// In this example case we are going to store:
6//   contact name, email address(es), phone number(s) and  creation date.
7String[] columns = {"Name", "E-Mail","Phone","Creation Date"};

1// First, populate our data object with some example values
2public void populateData(){
3  /* Two contacts*/
4  data = new Object[3][columns.length];
5  data[0][0] = "Peter";
6  String[] emails = {"peter@yahoo.com", "strange@name.com"};
7  data[0][1] = emails;
8  String[] phones = {"555 35 25 65" , "555 35 24 63"};
9  data[0][2] = phones;
10  data[0][3] = new Date();
11  data[1][0] = "Jackson";
12  data[1][1] = "Jack@hotmail.com";
13  String[] phones2 = {"555 35 24 33" , "555 11 88 88", "332 55 25 34"};
14  data[1][2] = phones2;
15  data[1][3] = new Date();
16  data[2][0] = "Robert";
17  data[2][1] = "rob@hotmail.com";
18  data[2][2] = "555 28 95 81";
19  data[2][3] = new Date();
20  /* As you can see, we've stored two contacts one with two e-mail accounts and two phone numbers,
21  and another member with three phone numbers */
22}
23// Next, we create our table models
24public void createModel(){
25  /* First we create the main model
26  We overide the AbstractTableModel necessary methods*/
27  AbstractTableModel modelo = new AbstractTableModel() {
28    public String getColumnName(int col) {
29      return columns[col];
30    }
31    public Class getColumnClass(int col) {
32      if(getRowCount() <1) {
33        return null;
34      }
35      return data[0][col].getClass();
36    }
37    public int getRowCount() {
38      return data.length;
39    }
40    public int getColumnCount() {
41      return columns.length;
42    }
43    public Object getValueAt(int row, int col) {
44      return data[row][col];
45    }
46    public boolean isCellEditable(int row, int col){
47      return true;
48    }
49    public void setValueAt(Object value, int row, int col) {
50      data[row][col] = value; fireTableCellUpdated(row, col);
51    }
52  };
53  /* We apply the model to the main jTable */
54  jTableData.setModel(modelo);
55  /* We create a cell Renderer to display the data of the multivalue fields*/
56  TableCellRenderer jTableCellRenderer = new TableCellRenderer() {
57    /* These are necessary variables to store the row's height */
58    private int minHeight = -1;
59    private int currHeight = -1;
60    /* Magic Happens */
61    public Component getTableCellRendererComponent(
62        JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
63      /* If what we're displaying isn't an array of values we return the normal renderer*/
64      if(!value.getClass().isArray()){
65        return table.getDefaultRenderer(value.getClass())
66            .getTableCellRendererComponent(table, value, isSelected, hasFocus,row, column);
67      } else{
68        final Object[] passed = (Object[])value;
69        /* We calculate the row's height to display data 
70        *  This is not complete and has some bugs that
71        *  will be analyzed in further articles */
72        if(minHeight == -1){
73          minHeight = table.getRowHeight();
74        }
75        if(currHeight != passed.length*minHeight){
76          currHeight = passed.length * minHeight;
77          table.setRowHeight(row,currHeight);
78        }
79        /* We create the table that will hold the multivalue
80        *  fields and that will be embedded in the main table */
81        return new JTable(new AbstractTableModel() {
82          public int getColumnCount() {
83            return 1;
84          }
85          public int getRowCount() {
86            return passed.length;
87          }
88          public Object getValueAt(int rowIndex, int columnIndex) {
89            return passed[rowIndex];
90          }
91          public boolean isCellEditable(int row, int col){
92            return true;
93          }
94        });
95      }
96    }
97  }; /* Finally we apply the new cellRenderer to the whole table */
98  TableColumnModel tcm = jTableData.getColumnModel();
99  for(int it = 0; it < tcm.getColumnCount(); it++){
100    tcm.getColumn(it).setCellRenderer(jTableCellRenderer);
101  }
102  // Note: if we need to edit the values inside the embedded jtable
103  // we will need to create a TableCellEditor too.
104}