1.创建News表
2.连接MySQL
package DAL; import com.mysql.jdbc.StatementImpl; import java.sql.*; public class SqlHelper { public static Connection getConnection() { Connection connection = null; try { Class.forName("com.mysql.jdbc.Driver"); connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/servletdata?useSSL=true&characterEncoding=utf-8&user=root&password="); System.out.println("数据库连接成功!"); System.out.println("-------------------------------"); return connection; } catch (Exception e) { e.printStackTrace(); } System.out.println("创建连接失败!"); System.out.println("-------------------------------"); return null; } //select public static ResultSet executeQuery(String SQL) { try { Connection conn=getConnection(); Statement stmt=conn.createStatement(); ResultSet rs=stmt.executeQuery(SQL); return rs; } catch (SQLException e) { e.printStackTrace(); System.out.println("查询失败!"); System.out.println("-------------------------------"); return null; } } //insert update delete public static boolean executeUpdate(String SQL) { try { Connection conn=getConnection(); Statement stmt=conn.createStatement(); int rs=stmt.executeUpdate(SQL); if (rs>0) return true; else return false; } catch (SQLException e) { e.printStackTrace(); System.out.println("更新失败!"); System.out.println("-------------------------------"); return false; } } public static void ShutDown(StatementImpl statement, Connection connection) { if (statement != null) { try { statement.close(); } catch (SQLException e) { e.printStackTrace(); } } if (connection != null) { try { connection.close(); } catch (SQLException e) { e.printStackTrace(); } } } }
3.射数据库中的news表
package Entity; import java.sql.Date; public class News { private int idnews; private String category; private String title; private String content; private String author; private Date newsdate; public int getIdnews() { return idnews; } public void setIdnews(int idnews) { this.idnews = idnews; } public String getCategory() { return category; } public void setCategory(String category) { this.category = category; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getContent() { return content; } public void setContent(String content) { this.content = content; } public String getAuthor() { return author; } public void setAuthor(String author) { this.author = author; } public Date getNewsdate() { return newsdate; } public void setNewsdate(Date newsdate) { this.newsdate = newsdate; } }
4.映射数据库中的users表
package Entity; public class Users { String name="";//用户名 String password="";//用户密码 public String getName() { return name; } public void setName(String name) { this.name = name; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } }
5.提供News类的数据服务
package Service; import DAL.SqlHelper; import Entity.News; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; public class NewsService { public void AddNews(){} public void DeleteNews(){} public void UpdateNews(){} public List<News> QueryNews() throws SQLException { String sql="Select * from news"; ResultSet rs= SqlHelper.executeQuery(sql); List<News> lsNews=new ArrayList<News>(); while (rs.next()) { News news=new News(); news.setIdnews(rs.getInt(1)); news.setCategory(rs.getString(2)); news.setTitle(rs.getString(3)); news.setContent(rs.getString(4)); news.setAuthor(rs.getString(5)); news.setNewsdate(rs.getDate(6)); lsNews.add(news); } return lsNews; } public void GetNews(){} }
6.提供Users类的数据服务
package Service; import DAL.SqlHelper; import Entity.News; import Entity.Users; import com.mysql.jdbc.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; public class UsersService { public void AddUsers(){} public void DeleteUsers(){} public void UpdateUsers(){} public boolean QueryUsers(Users user) throws SQLException { //验证用户名存在性 PreparedStatement pstmt; String sql = "select * from users where username='"+user.getName()+"' and password='"+user.getPassword()+"'"; ResultSet rs= SqlHelper.executeQuery(sql); if (rs.next()) { return true; } return false; } public void GetUsers(){} }
7.效果展示