jtable 合并单元格 详细代码

以下是使用 JTable 实现单元格合并的详细代码：

首先，我们需要自定义一个 TableModel 类来实现单元格合并：

import javax.swing.table.AbstractTableModel;
import java.util.HashMap;
import java.util.Map;
 
public class MergeTableModel extends AbstractTableModel {
    private Object[][] data;
    private String[] columnNames;
    private Map<CellIndex, CellSpan> spanMap;
 
    public MergeTableModel(Object[][] data, String[] columnNames) {
        this.data = data;
        this.columnNames = columnNames;
        this.spanMap = new HashMap<>();
    }
 
    public void merge(int startRow, int endRow, int startCol, int endCol) {
        spanMap.put(new CellIndex(startRow, startCol), new CellSpan(endRow - startRow + 1, endCol - startCol + 1));
    }
 
    @Override
    public int getRowCount() {
        return data.length;
    }
 
    @Override
    public int getColumnCount() {
        return columnNames.length;
    }
 
    @Override
    public Object getValueAt(int rowIndex, int columnIndex) {
        CellSpan span = spanMap.get(new CellIndex(rowIndex, columnIndex));
        if (span != null) {
            return null;
        }
        return data[rowIndex][columnIndex];
    }
 
    @Override
    public boolean isCellEditable(int rowIndex, int columnIndex) {
        return false;
    }
 
    public int getRealRow(int row) {
        int realRow = row;
        for (CellIndex cellIndex : spanMap.keySet()) {
            CellSpan span = spanMap.get(cellIndex);
            int endRow = cellIndex.row + span.row - 1;
            if (row >= cellIndex.row && row <= endRow) {
                realRow = cellIndex.row;
                break;
            }
        }
        return realRow;
    }
 
    public int getRealColumn(int column) {
        int realColumn = column;
        for (CellIndex cellIndex : spanMap.keySet()) {
            CellSpan span = spanMap.get(cellIndex);
            int endColumn = cellIndex.column + span.column - 1;
            if (column >= cellIndex.column && column <= endColumn) {
                realColumn = cellIndex.column;
                break;
            }
        }
        return realColumn;
    }
 
    public int getRowSpan(int row, int column) {
        CellSpan span = spanMap.get(new CellIndex(row, column));
        if (span != null) {
            return span.row;
        }
        return 1;
    }
 
    public int getColumnSpan(int row, int column) {
        CellSpan span = spanMap.get(new CellIndex(row, column));
        if (span != null) {
            return span.column;
        }
        return 1;
    }
 
    private static class CellIndex {
        private int row;
        private int column;
 
        private CellIndex(int row, int column) {
            this.row = row;
            this.column = column;
        }
 
        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;
            CellIndex cellIndex = (CellIndex) o;
            if (row != cellIndex.row) return false;
            return column == cellIndex.column;
        }
 
        @Override
        public int hashCode() {
            int result = row;
            result = 31 * result + column;
            return result;
        }
    }
 
    private static class CellSpan {
        private int row;
        private int column;
 
        private CellSpan(int row, int column) {
            this.row = row;
            this.column = column;
        }
    }
}

然后，我们在创建 JTable 的时候使用自定义的 TableModel 类，并在需要合并单元格的地方调用 merge 方法：

// 创建数据和列名
Object[][] data = {
    {"1", "A", "B", "C"},
    {"2", "D", "E", "F"},
    {"3", "G", "H", "I"},
    {"4", "J", "K", "L"}
};
String[] columnNames = {"#", "Column 1", "Column 2", "Column 3"};
 
// 创建自定义 TableModel
MergeTableModel tableModel = new MergeTableModel(data, columnNames);
 
// 创建 JTable
JTable table = new JTable(tableModel);
 
// 合并单元格
tableModel.merge(0, 1, 1, 2);
tableModel.merge(2, 3, 2, 3);
 
// 创建 JScrollPane 并将 JTable 添加到其中
JScrollPane scrollPane = new JScrollPane(table);

最后，我们需要重写 JTable 的 getCellRenderer 方法来实现单元格的合并显示：

// 创建 DefaultTableCellRenderer
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);
        int realRow = tableModel.getRealRow(row);
        int realColumn = tableModel.getRealColumn(column);
        int rowSpan = tableModel.getRowSpan(realRow, realColumn);
        int colSpan = tableModel.getColumnSpan(realRow, realColumn);
        if (rowSpan > 1 || colSpan > 1) {
            Rectangle rect = table.getCellRect(realRow, realColumn, false);
            for (int i = realRow; i < realRow + rowSpan; i++) {
                for (int j = realColumn; j < realColumn + colSpan; j++) {
                    if (i == realRow && j == realColumn) {
                        continue;
                    }
                    rect.add(table.getCellRect(i, j, false));
                }
            }
            c.setBounds(rect);
            ((JComponent) c).setOpaque(false);
        } else {
            ((JComponent) c).setOpaque(true);
        }
        return c;
    }
};
 
// 设置渲染器
table.setDefaultRenderer(Object.class, renderer);