firstcatalogpane.java

这是一个超市管理系统

package file2;
import java.sql.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class FirstCatalogPane extends JPanel implements ActionListener{
	//声明数据库连接组件
	private DBConnection con=null;
	private JLabel tip=null;
	private JLabel name=null;
	private JButton insert=null;
	private JButton reset=null;
	private JTextField nameTextField=null;
	private JPanel tipPane=null;
	private JPanel namePane=null;
	private JPanel buttonsPane=null;
	public FirstCatalogPane(){
		tip=new JLabel("请在下面输入商品大类名称");
		name=new JLabel("名称:");
		insert=new JButton("插入");
		reset=new JButton("重置");
		nameTextField=new JTextField(10);
		tipPane=new JPanel();
		tipPane.setLayout(new FlowLayout(FlowLayout.LEFT));
		tipPane.add(tip);
		namePane=new JPanel();
		namePane.setLayout(new FlowLayout(FlowLayout.LEFT));
		namePane.add(name);
		namePane.add(nameTextField);
		buttonsPane=new JPanel();
		buttonsPane.setLayout(new FlowLayout(FlowLayout.CENTER,5,5));
		buttonsPane.add(insert);
		buttonsPane.add(reset);
		this.setLayout(new GridLayout(3,1));
		this.add(tipPane);
		this.add(namePane);
		this.add(buttonsPane);
		insert.addActionListener(this);
		reset.addActionListener(this);
	}
	public void actionPerformed(ActionEvent e){
		if(e.getSource()==reset){
			nameTextField.setText("");
			return;
		}
		if(e.getSource()==insert){
			String name=nameTextField.getText().trim();
			if(name.equals("")){
				JOptionPane.showMessageDialog(null, "商品名称不能为空!", "提示", JOptionPane.ERROR_MESSAGE);
				return;
			}
			con=new DBConnection();
			String querySql="select* from First_Catalog where First_name='"+name+"'";
			String insertSql="insert into First_Catalog values('"+name+"')";
			try{
				ResultSet set=con.executeSelect(querySql);
				if(set.next()){
					JOptionPane.showMessageDialog(null, "该名称已经存在", "提示", JOptionPane.ERROR_MESSAGE);
					return;
				}
				con.executeDML(insertSql);
				JOptionPane.showMessageDialog(null, "插入成功!", "提示", JOptionPane.INFORMATION_MESSAGE);
				return;
			}catch(SQLException sql){
				JOptionPane.showMessageDialog(null, "发生SQL错误!", "提示", JOptionPane.ERROR_MESSAGE);
				return;
			}
		}
	}
}