• JSP显示新闻


    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

     GITEE地址:https://gitee.com/chenxingxin123/WEB.git

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  • 原文地址:https://www.cnblogs.com/565118008a/p/13129953.html
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