book_delete.java

图书馆管理系统 用swing界面做的一个图书馆管理系统 里面有增删改等功能 适合初学者看看

//图书删除
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.sql.*;

public class book_delete extends JFrame implements ActionListener{
	
	JLabel la_id=new JLabel("要删除的图书编号:");
	JLabel la_attention=new JLabel("注意: 编号规则为001-999");
	JLabel la_info=new JLabel("欲删除书目");
	
	JTextField t_delete=new JTextField(15);
	
	JButton b_demand=new JButton("查 询");
	JButton b_delete=new JButton("确认删除");
	JButton b_exit=new JButton("返 回");
	
	String[] tab_name={"书目编号","书名","ISBN号","价格","作者","出版社","简介"};
	String[][] tab_id=new String[1][7];
	
	JTable lab_delete=new JTable(tab_id,tab_name);
	JScrollPane sp = new JScrollPane(lab_delete);
	
	Connection conn=null;
	
	action_demand ac_demand= new action_demand();
	action_delete ac_delete= new action_delete();
	 
	public book_delete(){
		super("删除图书");
		this.setLayout(null);
		
		JPanel p=new JPanel();//菜单面板
		
		JPanel p1=new JPanel();//第一行
		JPanel p2=new JPanel();//第二行
		JPanel p3=new JPanel();//第三行
		
		JPanel p_info=new JPanel(); //提示信息面板
		
		
		p1.add(la_id); p1.add(t_delete);
		p2.add(la_attention);
		p3.add(b_demand); p3.add(b_delete); p3.add(b_exit);
		
		p.setBounds(3,10,790,100);//添加菜单栏
		p.setLayout(new GridLayout(3,1));
	//	p.setBackground(new Color(177,177,177));
		p.add(p1); p.add(p2); p.add(p3);
		this.add(p);
		
		p_info.setBounds(3,110,100,20);//添加提示信息
		p_info.add(la_info);
		this.add(p_info);
		
		sp.setBounds(3,140,795,180);
		this.add(sp);
		
		this.setBounds(200,200,800,280);
		this.setVisible(true);
		this.setResizable(false);
		//注册监听器
		b_demand.addActionListener(ac_demand);
		b_delete.addActionListener(ac_delete);
		b_exit.addActionListener(this);
		
		//连接数据库
		conn = book_sql.getConn();
		//System.out.println(conn);

	}
	public void actionPerformed(ActionEvent e){
			new book_main();//返回主菜单
			this.dispose();
	}
	//查询按钮
	class action_demand implements ActionListener{
		public void actionPerformed(ActionEvent e){
			String emp=t_delete.getText().trim(); //得到文本框的内容
			String sql=null;
			
			if(emp.equals("")){
				
				JOptionPane.showMessageDialog(null,"删除关键字不可为空",
							"Caution",JOptionPane.WARNING_MESSAGE);					
						return;
						
			}else{
				
				sql="select* from bookinfo where bid='"+emp+"'";
			    System.out.println(sql);
			    main_sql(sql);
			}
			
		}
		void main_sql(String sql){
			
			ResultSet rs = null;
			Statement st = null;
			
			try{
				st=conn.createStatement();
				rs=st.executeQuery(sql);
				
				rs.beforeFirst();//定位到结果集的首行
				
				while(rs.next()){
					tab_id[0][0] = rs.getString(1);
					tab_id[0][1] = rs.getString(2);
					tab_id[0][2] = rs.getString(3);
					tab_id[0][3] = rs.getString(4);
					tab_id[0][4] = rs.getString(5);
					tab_id[0][5] = rs.getString(6);
					tab_id[0][6] = rs.getString(7);
							
				}
				
			}catch(SQLException sqle){
				sqle.printStackTrace();
			}
			
			lab_delete.repaint(); //显示数据库里面的信息
		}
	}
	// 删除按钮
	class action_delete implements ActionListener{
		public void actionPerformed(ActionEvent e){
			
			ResultSet rs = null;
			Statement st = null;
			
			String emp=t_delete.getText().trim(); //得到文本框的内容
			if(emp.equals("")){
				
				JOptionPane.showMessageDialog(null,"确认删除的关键字不可为空",
							"Caution",JOptionPane.WARNING_MESSAGE);					
						return;
						
			}else{
				try{
					st=conn.createStatement();
				
					String sql="delete from bookinfo where bid='"+emp+"'";
					System.out.println(sql);
					
					st.executeUpdate(sql);
					
				}catch(SQLException sqle){
					sqle.printStackTrace();
				}
				
				JOptionPane.showMessageDialog(null,"删除成功",
							"Caution",JOptionPane.WARNING_MESSAGE);					
						return;						
			}
			//t_delete.setText(""); //清空关键字输入框?????								
		}			
	}
    //
}