根据来自 msyql 的结果集值更改 Jtable 单元格的颜色

Question

我使用 Netbeans 开发一个 java 应用程序，我有一个来自 MYSQL 数据库的结果集，我想把这些数据放在一个 JTable 中。 当我想根据值更改 JTable 单元格的背景颜色时遇到问题（例如：如果 Jtable 中单元格的值不等于 1，则其颜色必须为红色）。 这是我的代码：

    /*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * 
 */
import java.awt.Color;
import java.awt.Component;
import java.awt.Font;
import java.sql.*;
import java.util.Vector;
import javax.swing.JTable;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableColumn;

public class Cell2 {

    // JDBC driver name and database URL
    static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    static final String DB_URL = "jdbc:mysql://localhost/db";

    //  Database credentials
    static final String USER = "root";
    static final String PASS = "(abdc)";

    public void queryABTS(JTable table) {
        Connection conn = null;
        Statement stmt = null;
        try {
            //STEP 2: Register JDBC driver
            Class.forName("com.mysql.jdbc.Driver");

            //STEP 3: Open a connection
            System.out.println("Connecting to database...");
            conn = DriverManager.getConnection(DB_URL, USER, PASS);

            //STEP 4: Execute a query
            System.out.println("Creating statement...");
            stmt = conn.createStatement();
            String sql;
            sql = "SELECT * from dbn;";
            ResultSet rs = stmt.executeQuery(sql);
            ResultSetMetaData rsmt = rs.getMetaData();
            int c = rsmt.getColumnCount();
            Vector column = new Vector(c);
            for (int i = 1; i <= c; i++) {
                column.add(rsmt.getColumnName(i));
            }
            Vector data = new Vector();
            Vector row = new Vector();
            while (rs.next()) {
                row = new Vector(c);
                for (int i = 1; i <= c; i++) {
                    row.add(rs.getString(i));
                }
                data.add(row);
            }

            table.setModel(new javax.swing.table.DefaultTableModel(data, column));
            table.getTableHeader().setFont(new Font("SansSerif", Font.BOLD, 13));
           // table.getValueAt(1, 1);

            TableColumn column1 = null;

            for (int i = 0; i < 5; i++) {
                column1 = table.getColumnModel().getColumn(i);
                if (i == 3) {
                    column1.setPreferredWidth(150); //third column is bigger

                } else {
                    column1.setPreferredWidth(50);

                }
            }

            setCellRenderer(table);
            //color cell =======================================================================

             // end color cell ==================================================================


//========================================================

//=======================================================
            //STEP 6: Clean-up environment
            rs.close();
            stmt.close();
            conn.close();
        } catch (SQLException se) {
            //Handle errors for JDBC
            se.printStackTrace();
        } catch (Exception e) {
            //Handle errors for Class.forName
            e.printStackTrace();
        } finally {
            //finally block used to close resources
            try {
                if (stmt != null) {
                    stmt.close();
                }
            } catch (SQLException se2) {
            }// nothing we can do
            try {
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException se) {
                se.printStackTrace();
            }//end finally try
        }//end try
        System.out.println("Goodbye!");
    }//end main  


public static TableCellRenderer createCellRenderer() {
    return 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);

            if (column == 4 && "1".equals((String) value)) {
    c.setBackground(Color.RED);
    }

            return c;
        }
    };
}

public static void setCellRenderer(JTable table) {
    TableCellRenderer cellRenderer = createCellRenderer();
    table.setDefaultRenderer(Object.class, cellRenderer);
}





}

Answer 1

尝试这个

public static TableCellRenderer createCellRenderer() {
    return 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);

            c.setBackground(Color.GREEN);

            return c;
        }
    };
}

public static void setCellRenderer(JTable table) {
    TableCellRenderer cellRenderer = createCellRenderer();
    table.setDefaultRenderer(Object.class, cellRenderer);
}

通过调用table.setModel(new javax.swing.table.DefaultTableModel(data, column)); 您正在将数据放入表模型中。 JTable默认使用DefaultTableCellRenderer实例来渲染单元格，可以通过调用table.setDefaultRenderer(Integer.class, cellRenderer)将其替换为您自己的单元格渲染器 - 这会将自定义 cellrenderer 设置为所有Integer列（ DefaultTableModel使用Object列）。 显示表格时，表格的每个单元格都由表格的cellrenderer 的getTableCellRendererComponent(...)方法自定义。 在此方法中，您拥有当前组件（单元格）及其值和位置（请参阅参数），您可以使用它们在渲染之前自定义单元格。

因此，如果您想将第二列中值为 1 的每个单元格的背景颜色设置为红色，您可以这样写：

if (column == 1 && ((Integer) value) == 1) {
    c.setBackground(Color.RED);
}

将表的data传递给单元格渲染器

public static TableCellRenderer createCellRenderer(final Vector data) {
    return 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);

            // use data to customize current component

            return c;
        }
    };
}

public static void setCellRenderer(JTable table, Vector data) {
    // Vector data = ((DefaultTableModel) table.getModel()).getDataVector();
    TableCellRenderer cellRenderer = createCellRenderer(data);
    table.setDefaultRenderer(Object.class, cellRenderer);
}

Answer 2

public class Product extends javax.swing.JPanel {
     
    public Product() {
        initComponents();
         
       getNewRenderedTable(p_table);
       
    }
      
    private static JTable getNewRenderedTable(final JTable table){
        table.setDefaultRenderer(Object.class, new DefaultTableCellRenderer(){
            @Override
            public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column){
                super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
                
                int status = Integer.parseInt((String) table.getModel().getValueAt(row, 7));
                
                if(status<=5){
                   setBackground(Color.red);
                   setForeground(Color.WHITE);
                }
                else{
                   setBackground(Color.WHITE);
                   setForeground(Color.black);
                }
                return this;
            }
        });
        return table;
    }

}