我正在处理这个应用程序，但我无法让 GUI 正确显示。我正在使用 FlowLayout，一切看起来都很混乱（任何其他布局看起来更糟）。如果只有某种方法可以在部分之间添加水平规则，那将起作用，但我尝试过的任何方法都不起作用。
这是我的代码：
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import javax.swing.*;
public class ConnectToDB implements ActionListener {
public static void main(String[] args){
//GUI STUFF
//constants
final int windowX = 640; //pixels
final int windowY = 655; //pixels
final int fieldX = 20; //characters
final FlowLayout LAYOUT_STYLE = new FlowLayout();
//window
JFrame window = new JFrame("Mike's MySQL GUI Client");
//Connection Details
JLabel enterInfo = new JLabel("Enter Connection Details: ");
JLabel driver = new JLabel("Database Driver: ");
JTextField driverText = new JTextField(fieldX);
JLabel dburl = new JLabel("Database URL: ");
JTextField dburlText = new JTextField(fieldX);
JLabel dbuser = new JLabel("Username: ");
JTextField dbuserText = new JTextField(fieldX);
JLabel dbpass = new JLabel("Password: ");
JTextField dbpassText = new JTextField(fieldX);
//Enter a SQL Command
JLabel enterSQL = new JLabel("Enter a SQL Command:");
JTextArea enterSQLText = new JTextArea(10, 30);
//Connection Status and Command Buttons
JLabel connectionStatus = new JLabel ("No Connection Now");
JButton connectButton = new JButton("Connect");
JButton executeButton = new JButton("Execute SQL Command");
JButton clearCommandButton = new JButton("Clear Command");
//SQL Execution Result
JLabel executionResult = new JLabel("SQL Execution Result:");
JButton clearResultsButton = new JButton("Clear Results");
JTextArea executionResultText = new JTextArea(20, 50);
//Configure GUI
window.setSize(windowX, windowY);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
driverText.setEditable(false);
dburlText.setEditable(false);
dbuserText.setEditable(false);
dbpassText.setEditable(false);
executionResultText.setEditable(false);
//Register Event Listeners
connectButton.addActionListener(null);
executeButton.addActionListener(null);
clearCommandButton.addActionListener(null);
clearResultsButton.addActionListener(null);
//Construct Container
Container c = window.getContentPane();
c.setLayout(LAYOUT_STYLE);
c.add(enterInfo);
c.add(driver);
c.add(driverText);
c.add(dburl);
c.add(dburlText);
c.add(dbuser);
c.add(dbuserText);
c.add(dbpass);
c.add(dbpassText);
c.add(connectionStatus);
c.add(connectButton);
c.add(enterSQL);
c.add(enterSQLText);
c.add(executeButton);
c.add(clearCommandButton);
c.add(new JSeparator(SwingConstants.VERTICAL));
c.add(executionResult);
c.add(clearResultsButton);
c.add(executionResultText);
window.setVisible(true);//END GUI STUFF
//DB Connection details
System.out.println("Attempting to connect to database...");
Connection conn = null;
String url = "jdbc:mysql://localhost/";
String dbName = "project3";
String DBdriver = "com.mysql.jdbc.Driver";
String userName = "root";
String password = "OMGnpw=-0";
driverText.setText(DBdriver);
dburlText.setText(url);
dbuserText.setText(userName);
dbpassText.setText(password);
try
{
//Connect to DB and notify user
Class.forName(DBdriver).newInstance();
conn = DriverManager.getConnection(url+dbName,userName,password);
System.out.println("Connected to the database");
/*>>>>>>Do everything you need to do while connected to DB<<<<<<*/
//HOW TO EXECUTE A STATEMENT AND PRINT IT
//Create a statement
Statement statement = conn.createStatement();
//Execute a statement
ResultSet resultSet = statement.executeQuery("SELECT * FROM riders");
//Process query results
ResultSetMetaData metaData = resultSet.getMetaData();
int numberOfColumns = metaData.getColumnCount();
for(int i = 1; i<= numberOfColumns; i++){
System.out.printf("%20s\t", metaData.getColumnName(i));
}
System.out.println();
while (resultSet.next()){
for (int i = 1; i <= numberOfColumns; i++){
System.out.printf("%20s\t", resultSet.getObject(i));
}
System.out.println();
}
/*>>>>>>Finish DB activities<<<<<<*/
//Disconnect from DB
conn.close();
System.out.printf("Disconnected from database");
}
catch (Exception e) {
e.printStackTrace();
}
}
public void actionPerformed(ActionEvent e){
System.out.println("Button Works!");
}
}
我可能需要使用不同的布局，但 FlowLayout 是我唯一熟悉的布局。谁能建议一个简单的解决方法？
