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java - 没有列名的 DefaultTableModel

转载 作者:塔克拉玛干 更新时间:2023-11-01 21:42:00 24 4
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这个类与我的数据库通信检索数据并将它们投影到 JTable。我使用了 DefaultTableModel 但列名不会出现。我在另一个类中实例化这个类,我通过 检索包含数据的表获取表格()

package jtable;

import javax.swing.*;
import javax.swing.table.*;
import java.sql.*;

public class ControlDatabase
{
private JTable table;
private Statement stmt;
private DefaultTableModel model;
private String all = "SELECT * FROM Players ORDER BY id ASC";


public ControlDatabase( )
{
String dbUsername = "root";
String dbPassword = "*****";
String dbHost = "localhost";
String dbPort = "3306";
String dbName = "oop_project_database";
String url = "jdbc:mysql://" + dbHost + ":" + dbPort + "/" + dbName;
try {
Connection con = DriverManager.getConnection(url, dbUsername, dbPassword);

model = new DefaultTableModel();
model.addColumn("Id");
model.addColumn("Onoma");
model.addColumn("Epwnimo");
model.addColumn("Age");
model.addColumn("Nickname");
table = new JTable(model);

stmt = con.createStatement();
updateStatement( all );

} catch (SQLException ex) {
ex.printStackTrace(System.out);
}

}

public void addStatement(String name,String surname,Integer age,String nickname )
{
String query = "INSERT INTO Players (name,surname,age,nickname) VALUES ('"
+ name +
"','"
+ surname +
"',"
+ age +
",'"
+ nickname +
"')";
try {
int x = stmt.executeUpdate( query );
if (x > 0) {
lastStatement(all);
// updateStatement(all , true );
}
} catch (SQLException e) {
e.printStackTrace();
}
}

public Boolean deleteStatement(String id , int row )
{
String query = "DELETE FROM Players WHERE id = " + id ;
try {
int x = stmt.executeUpdate( query );
if (x > 0) {
model.removeRow(row);
return true;
}
return false;

} catch (SQLException e) {
e.printStackTrace();
return false;
}
}

public void updateStatement(String query , Boolean flag )
{
try {
ResultSet rs = stmt.executeQuery( query );
while (rs.next()) {
int currentId = rs.getInt("id");
String currentName = rs.getString("name");
String currentSurname = rs.getString("surname");
int currentAge = rs.getInt("age");
String currentNick = rs.getString("nickname");

Object[] currentRow = { currentId ,currentName, currentSurname, currentAge, currentNick };
model.addRow(currentRow);
}
} catch (SQLException ex) {
ex.printStackTrace(System.out);
}
}

public void updateStatement(String query) {
updateStatement(query , false );
}

public void lastStatement(String query )
{
try {
ResultSet rs = stmt.executeQuery( query );

rs.last();
int currentId = rs.getInt("id");
String currentName = rs.getString("name");
String currentSurname = rs.getString("surname");
int currentAge = rs.getInt("age");
String currentNick = rs.getString("nickname");
Object[] currentRow = { currentId ,currentName, currentSurname, currentAge, currentNick };
model.addRow(currentRow);
} catch (SQLException ex) {
ex.printStackTrace(System.out);
}
}

public JTable getTable( ) {
return table;
}

}

主类

package jtable;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;


public class MainD extends JFrame{

private JPanel p;
//private JPanel pa;
private JScrollPane pa; //<-- change
private JSplitPane splitPane;
private JButton b,ba;
private JLabel ln,ls,la,lc;
private JTextField txs,txn,txa,txc;
private ControlDatabase data;
private JTable table;

public MainD()
{
super("Split");
p = new JPanel(new GridLayout(5,2));
//pa = new JPanel(new GridLayout(1,1));
pa = new JScrollPane( ); //<--
ln = new JLabel("Name");
txn = new JTextField();
ls = new JLabel("Surname");
txs = new JTextField();
la = new JLabel("Age");
txa = new JTextField();
ba = new JButton("Add");
lc = new JLabel("Nickname");
txc = new JTextField();
ba.addActionListener(new ActionListener() { //Add
public void actionPerformed(ActionEvent e){
String name = txn.getText();
String surname = txs.getText();
String sage = txa.getText();

String nickname = txc.getText();
if (!( name.isEmpty() || surname.isEmpty() || nickname.isEmpty() || sage.isEmpty() )) {
try {
Integer age = Integer.parseInt( sage );
data.addStatement(name,surname,age,nickname);
txn.setText("");
txs.setText("");
txa.setText("");
txc.setText("");
}catch(NumberFormatException ex){
System.out.println("Age must be an Integer");
}

}
else{
System.out.println("Empty Fields");
}
}
}
);
b = new JButton("Remove");
data = new ControlDatabase();
table = data.getTable();
pa.add(table);
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e){
int row = table.getSelectedRow();
String value = String.valueOf( table.getValueAt( row ,0 ) );
data.deleteStatement( value , row );
}
}
);
p.add(ln);
p.add(txn);
p.add(ls);
p.add(txs);
p.add(la);
p.add(txa);
p.add(lc);
p.add(txc);
p.add(ba);
p.add(b);
splitPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, p, pa);
splitPane.setDividerLocation(280);
add(splitPane);
setBounds(200,200,800,400);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setVisible(true);
}

public static void main(String[] args) {
new MainD();
}

}

最佳答案

您可能没有将表格放在 JScrollPane 中,这就是它不绘制标题的原因。或者调用getTableHeader()单独添加。引用自 JTable javadoc :

Note that if you wish to use a JTable in a standalone view (outside of a JScrollPane) and want the header displayed, you can get it using getTableHeader() and display it separately.

编辑:要将组件添加到 JScrollPane,要么将组件提供给 JScrollPane 的构造函数,要么调用 JScrollPane.setViewportView(component)

关于java - 没有列名的 DefaultTableModel,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/7944819/

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