Servlet——利用数据库、前后端接口实现一个简单的博客系统

需求分析

1)注册新用户
2)登陆已有用户
3)展示博客列表(每项包含了文章的标题,作者)
点击标题就会跳转到文章详情页.
分页功能也暂时不考虑
4)文章详情页中,可以看到文章标题,作者,文章内容
评论功能，分类功能,推荐相关文章功能等,先不考虑
5)发布新的博客（不考虑富文本编辑.）
6)删除自己的博客

数据库设计

1、提取需求中的实体

两张表User Article

2、实体的属性

用户： 名字 密码
文章： 标题 内容

3、实体之间关系

一对多
a）user表中加入一个userId字段，身份标识
b）Article表中加入一个userId字段，表示该文章是哪个用户发的

数据库建表

drop database if exists myBlog;
create database myblog;

use myblog;

drop table if exists user;
create table user (
    userId int primary key auto_increment,
    name varchar(50) unique,
    password varchar(50)
);

drop table if exists article;
create table article (
    articleId int primary key auto_increment,
    title varchar(255),
    content text,
    userId int,
    foreign key(userId) references user(userId)
);

Java代码操作

a）创建一个类，管理数据库的连接

import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DButil {
    private static String url = "jdbc:mysql://127.0.0.1:3306/blog?characterEncoding=utf-8&useSSL=true";
    private static String username = "root";
    private static String password = "";

    private static volatile DataSource DATASOURCE = null;

    private static DataSource getDATASOURCE() {
        //双层校验锁

        if(DATASOURCE == null){
            synchronized (DButil.class){
                if(DATASOURCE == null){
                    DATASOURCE = new MysqlDataSource();
                    ((MysqlDataSource)DATASOURCE).setUrl(url);
                    ((MysqlDataSource)DATASOURCE).setUser(username);
                    ((MysqlDataSource)DATASOURCE).setPassword(password);
                }
            }
        }
        return DATASOURCE;
    }

    public static Connection getConnect(){
        try{
            //从池子中获取连接
            Connection connection = getDATASOURCE().getConnection();
            return connection;
        } catch (SQLException e) {
            e.printStackTrace();
            throw new RuntimeException("获取数据库连接失败！");
        }
    }

    //断开连接
    public static void getClose(Connection connection,
                                PreparedStatement statement,
                                ResultSet resultSet){
        if(resultSet != null){
            try {
                resultSet.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(statement != null){
            try {
                statement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(connection != null){
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

b）创建实体类

创建一个User类和Article类
这俩类的属性,要和数据库表结构,是相关联的

public class User {
    private int userId;
    private String userName;
    private String password;

    public int getUserId() {
        return userId;
    }

    public void setUserId(int userId) {
        this.userId = userId;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "User{" +
                "userId=" + userId +
                ", userName='" + userName + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

public class Article {
    private int articleId;
    private String articleTitle;
    private String articleContent;
    private int userId;

    public int getArticleId() {
        return articleId;
    }

    public void setArticleId(int articleId) {
        this.articleId = articleId;
    }

    public String getArticleTitle() {
        return articleTitle;
    }

    public void setArticleTitle(String articleTitle) {
        this.articleTitle = articleTitle;
    }

    public String getArticleContent() {
        return articleContent;
    }

    public void setArticleContent(String articleContent) {
        this.articleContent = articleContent;
    }

    public int getUserId() {
        return userId;
    }

    public void setUserId(int userId) {
        this.userId = userId;
    }

    @Override
    public String toString() {
        return "Article{" +
                "articleId=" + articleId +
                ", articleTitle='" + articleTitle + '\'' +
                ", articleContent='" + articleContent + '\'' +
                ", userId=" + userId +
                '}';
    }
}

c）实现数据库的基本的增删改查

DAO表示数据访问层.
通过UserDao这个类来完成针对用户的数据库表操作.

import DButil.DButil;
import Entity.User;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class UserDao {

    //新增用户（注册）
    public void add(User user){
        Connection connection = null;
        PreparedStatement preparedStatement = null;

        String sql = "insert into user values (null ,?,?)";

        try {
            connection = DButil.getConnect();
            preparedStatement = connection.prepareStatement(sql);
            preparedStatement.setString(1,user.getUserName());
            preparedStatement.setString(2,user.getPassword());

            int ret = preparedStatement.executeUpdate();
            if (ret != 1) {
                System.out.println("插入新用户失败!");
                return;
            }
            System.out.println("插入新用户成功");
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            DButil.getClose(connection,preparedStatement,null);
        }
    }

    //按照名字查找用户（登录）
    public User findUserByName(String name){
        Connection connection = null;
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;

        String sql="select * from user where userName=?";
        try{
            assert connection != null;
            connection = DButil.getConnect();
            preparedStatement = connection.prepareStatement(sql);
            preparedStatement.setString(1,name);
            resultSet = preparedStatement.executeQuery();
            if (resultSet.next()){
                User user = new User();
                user.setUserId(resultSet.getInt("userId"));
                user.setUserName(resultSet.getString("userName"));
                user.setPassword(resultSet.getString("password"));
                return user;


            }
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            DButil.getClose(connection,preparedStatement,resultSet);
        }
        return null;
    }

    //通过id查找用户
    public User findUserById(int id){
        Connection connection = null;
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;

        String sql = "select * from user where userId = ?";
        try{
            connection = DButil.getConnect();
            preparedStatement = connection.prepareStatement(sql);
            preparedStatement.setInt(1,id);
            resultSet = preparedStatement.executeQuery();
            if (resultSet.next()){
                User user = new User();
                user.setUserId(resultSet.getInt("userId"));
                user.setUserName(resultSet.getString("userName"));
                user.setPassword(resultSet.getString("password"));
                return user;

            }

        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            DButil.getClose(connection,preparedStatement,resultSet);
        }
        return null;

    }

   /* public static void main(String[] args) {
        UserDao userDao = new UserDao();
        User user = new User();
        user.setUserName("hhh");
        user.setPassword("123");

        userDao.add(user);

        System.out.println(findUserByName("hhh"));
        System.out.println(findUserById(1));
    }*/

}

通过ArticleDao这个类完成针对文章的数据库表操作.

import DButil.DButil;
import Entity.Article;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class ArticleDao {
    //1、新增文章（发布博客）
    public static void add(Article article){
        Connection connection = null;
        PreparedStatement preparedStatement = null;


        String sql = "insert into article values (null,?,?,?)";
        try{
            connection = DButil.getConnect();
            preparedStatement = connection.prepareStatement(sql);
            preparedStatement.setString(1,article.getArticleTitle());
            preparedStatement.setString(2,article.getArticleContent());
            preparedStatement.setInt(3,article.getUserId());

            int ret = preparedStatement.executeUpdate();
            if(ret != 1){
                System.out.println("文章添加失败！");
                return;
            }else {
                System.out.println("文章添加成功！");
            }

        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            DButil.getClose(connection,preparedStatement,null);
        }
    }
    //2、查看文章列表（把所有文章信息都查出来，不查正文）\
    public List<Article> findArticleList(){
        Connection connection = null;
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;
        List<Article> articleList = new ArrayList<>();


        String sql = "select articleId,articleTitle,userId from article";
        try{
            connection = DButil.getConnect();
            preparedStatement = connection.prepareStatement(sql);
            resultSet = preparedStatement.executeQuery();

            while (resultSet.next()){
             Article article = new Article();
             article.setArticleId(resultSet.getInt("articleId"));
             article.setArticleTitle(resultSet.getString("articleTitle"));
             article.setUserId(resultSet.getInt("userId"));

             articleList.add(article);

            }
            return articleList;

        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            DButil.getClose(connection,preparedStatement,resultSet);
        }
        return null;
    }
    //3、根据文章id查看指定文章详情(查看正文)
    public Article findArticleByArticleId(int articleId){
        Connection connection = null;
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;


        String sql = "select * from article where articleId=?";
        try{
            connection = DButil.getConnect();
            preparedStatement = connection.prepareStatement(sql);
            preparedStatement.setInt(1,articleId);
            resultSet = preparedStatement.executeQuery();

            if (resultSet.next()){
                Article article = new Article();
                article.setArticleId(resultSet.getInt("articleId"));
                article.setArticleTitle(resultSet.getString("articleTitle"));
                article.setArticleContent(resultSet.getString("articleContent"));
                article.setUserId(resultSet.getInt("userId"));
                return article;
            }

        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            DButil.getClose(connection,preparedStatement,resultSet);
        }
        return null;

    }

    //4、删除指定文章（给定文章ID删除）
    public void  deleteArticle(int articleId){
        Connection connection = null;
        PreparedStatement preparedStatement = null;

        String sql ="delete from article where articleId =?";
        try{
            connection = DButil.getConnect();
            preparedStatement = connection.prepareStatement(sql);
            preparedStatement.setInt(1,articleId);
            int ret = preparedStatement.executeUpdate();
            if(ret != 1){
                System.out.println("删除文章失败！");
                return;
            }else {
                System.out.println("删除文章成功！");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            DButil.getClose(connection,preparedStatement,null);
        }
    }

   /*public static void main(String[] args) {
        ArticleDao articleDao = new ArticleDao();
        Article article = new Article();
        article.setArticleTitle("爱你就像爱生命");
        article.setArticleContent("一想到你我这张丑脸就泛起微笑！");
        article.setUserId(1);
        articleDao.add(article);
       *//* System.out.println(findArticleList());
        System.out.println(findArticleByArticleId(4));*//*
    }
*/
}

前后端接口设计并实现

约定,服务器都能接收啥样的请求,每个请求具体的格式如何,对应的响应结果又如何.（自定制协议，基于http的基础上进行拓展）

1）获取注册页面

GET/register.html（GET /signup.html）
前后端按照同一种方式开发

<!DOCTYPE html>
<html lang="zxx">

<head>
    <title>注册</title>
    <!-- Meta tags -->
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <!-- //Meta tags -->
    <link rel="stylesheet" href="css/style.css" type="text/css" media="all" /><!-- Style-CSS -->
</head>

<body>
<section class="w3l-coming-soon">
    <div class="bgimg text-center">
        <div class="topleft">
            <a class="brand-logo" href="#index.html">Adventure</a>
        </div>
        <div class="middle">
            <h2>Stay Tuned</h2>
            <h1>We ARE COMING SOON</h1>

            <p id="demo"></p>

            <div class="form-right-inf">
                <form action="register" method="post" >
                    <div class="forms-gds">
                        <input type="text" name="userName" placeholder="请输入用户名" >
                        <br/>
                        <input type="text" name="password" placeholder="请输入密码" >
                        <br/>
                        <button class="btn theme-button">注册</button>
                    </div>
                </form>

            </div>
        </div>
        <!-- copyright -->
        <!-- //copyright -->
    </div>

</section>

</body>
</html>

响应：
注册页面，页面上带有两个输入框（输入用户名密码）一个提交按钮

2）实现注册功能(注册页面中提交的form表单数据，需要服务器处理)

请求：
POST/register
name = XXX&password=XXX

import Dao.UserDao;
import Entity.User;
import View.HtmlGenerator;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class RegisterServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        resp.setContentType("text/html; charset=utf-8");
        String name = req.getParameter("userName");
        String password = req.getParameter("password");
        // 1. 获取到前端提交的数据(用户名, 密码), 校验是否合法.
        if(name == null|| "".equals(name) || password == null|| "".equals(password)){
            String html = HtmlGenerator.getMessagePage("用户名或者密码为空！",
                    "register.html");
            resp.getWriter().write(html);
            return;
        }

        // 2. 拿着用户名在数据库中查一下, 看看当前用户名是否已经存在. 如果存在, 认为注册失败(用户名不能重复)
        UserDao userDao = new UserDao();
        User existUser = userDao.findUserByName(name);

        if(existUser != null){
            String html = HtmlGenerator.getMessagePage("用户名重复！","register.html");
            resp.getWriter().write(html);
            return;
        }
        // 3. 根据前端提交的数据, 构造 User 对象并插入到数据库中.
        User user = new User();
        user.setUserName(name);
        user.setPassword(password);
        userDao.add(user);

        // 4. 返回一个结果页面, 提示当前注册成功.
        String html = HtmlGenerator.getMessagePage("注册成功！",
                "login.html");
        resp.getWriter().write(html);

    }
}

响应：
返回一个提示页面，告诉用户注册成功还是失败，并且能跳转到登录页面

3）获取登录页面

请求
GET/login.html

<!DOCTYPE html>
<html lang="zxx">

<head>
    <title>登录</title>
    <!-- Meta tags -->
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <!-- //Meta tags -->
    <link rel="stylesheet" href="css/style.css" type="text/css" media="all" /><!-- Style-CSS -->
</head>

<body>
<section class="w3l-coming-soon">
    <div class="bgimg text-center">
        <div class="topleft">
            <a class="brand-logo" href="#index.html">Adventure</a>
        </div>
        <div class="middle">
            <h2>Stay Tuned</h2>
            <h1>We ARE COMING SOON</h1>

            <p id="demo"></p>

            <div class="form-right-inf">
                <form action="login" method="post" >
                    <div class="forms-gds">
                        <input type="text" name="userName" placeholder="请输入用户名" >
                        <br/>
                        <input type="text" name="password" placeholder="请输入密码" >
                        <br/>
                        <button class="btn theme-button">登录</button>
                    </div>
                </form>

            </div>
        </div>
        <!-- copyright -->
        <!-- //copyright -->
    </div>

</section>

</body>
</html>

在这里插入代码片

响应：
返回一个登陆页面，包含两个输入框和一个登录按钮

4）实现登录功能（登陆页面提交的数据，需要服务器来处理

请求：
POST/login
name = XXX&password=XXX

import Dao.UserDao;
import Entity.User;
import View.HtmlGenerator;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

public class LoginServlet extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        resp.setContentType("text/html; charset=utf-8");
        String name = req.getParameter("userName");
        String password = req.getParameter("password");
        // 1. 获取到用户名和密码. 并进行简单校验
        if(name == null || "".equals(name) || password == null || "".equals(password)){
            String html = HtmlGenerator.getMessagePage("用户名或者密码为空！","login.html");
            resp.getWriter().write(html);
            return;
        }
        // 2. 数据库中查找, 看用户是否存在.
        // 3. 对比密码是否匹配

        UserDao userDao = new UserDao();
        User user = userDao.findUserByName(name);
        if(user == null || !password.equals(user.getPassword())){
            String html = HtmlGenerator.getMessagePage("用户名或者密码错误！","login.html");
            resp.getWriter().write(html);
            return;
        }
        // 4. 匹配成功则认为登陆成功, 创建一个 Session
        HttpSession httpSession = req.getSession(true);
        httpSession.setAttribute("user",user);
        // 5. 返回一个登陆成功的提示页面
        String html = HtmlGenerator.getMessagePage("登陆成功!",
                "article");
        resp.getWriter().write(html);

    }
}

响应：
返回一个提示页面，告诉用户登录成功还是失败

5）获取文章列表

请求：
GET/article

响应：
返回文章的列表页面（包含一些文章的标题，点击标题进入到详情页）

6)获取文章详细内容

请求:
GET /article?articleld= 1

响应:
返回文章的详情页(包含文章的内容)

7)新增/发布文章

请求:
POST /article
title=xxx&content= xXXX
响应:
返回一一个提示页面,告诉用户发布成功还是失败.

5-7

import Dao.ArticleDao;
import Dao.UserDao;
import Entity.Article;
import Entity.User;


import View.HtmlGenerator;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.util.List;

public class ArticleServlet extends HttpServlet {

    //获取文章列表 获取文章详细内容
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        resp.setContentType("text/html; charset=utf-8");
        // 1. 判定用户的登陆状态. 如果用户尚未登陆, 就要提示用户来登陆.
        HttpSession httpSession = req.getSession(false);
        if (httpSession == null) {
            String html = HtmlGenerator.getMessagePage("您尚未登陆",
                    "login.html");
            resp.getWriter().write(html);
            return;
        }
        User user = (User) httpSession.getAttribute("user");
        // 2. 判断请求中是否存在 articleId 参数.
        String articleIdStr = req.getParameter("articleId");
        if (articleIdStr == null) {
            //  a) 没有这个参数就去执行获取文章列表操作articleDao中查找文章列表不需要id
            getAllArticleList(user, resp);

        } else {
            //  b) 有这个参数就去执行获取文章详情操作.
            getOneArticle(Integer.parseInt(articleIdStr), user, resp);

        }
    }
        private void getAllArticleList(User user, HttpServletResponse resp) throws IOException  {
            // 1. 查找数据库
            ArticleDao articleDao = new ArticleDao();
            List<Article> articleList = articleDao.findArticleList();
            // 2. 构造页面
            String html = HtmlGenerator.getArticleListPage(articleList, user);
            resp.getWriter().write(html);


        }
        private void getOneArticle(int articleId, User user, HttpServletResponse resp) throws IOException {
            // 1. 查找数据库
            ArticleDao articleDao = new ArticleDao();
            Article article = articleDao.findArticleByArticleId(articleId);
            if (article == null) {
                //文章未找到
                String html = HtmlGenerator.getMessagePage("文章不存在",
                        "article");
                resp.getWriter().write(html);
                return;
            }
            // 2. 根据作者id 找到作者信息, 进一步得到作者姓名
            UserDao userDao = new UserDao();
            User author = userDao.findUserById(article.getUserId());
            // 3. 构造页面
            String html = HtmlGenerator.getArticleDetailPage(article, user, author);
            resp.getWriter().write(html);

        }

    //实现新增文章
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        resp.setContentType("text/html; charset=utf-8");
        // 1. 判定用户的登陆状态. 如果用户尚未登陆, 就要提示用户来登陆.
        HttpSession httpSession = req.getSession(false);
        if (httpSession == null) {
            String html = HtmlGenerator.getMessagePage("您尚未登陆",
                    "login.html");
            resp.getWriter().write(html);
            return;
        }
        User user = (User) httpSession.getAttribute("user");

        // 2. 从请求中读取浏览器提交的数据(title, content), 并进行简单校验
        String title = req.getParameter("articleTitle");
        String content = req.getParameter("articleContent");
        if (title == null || "".equals(title)
                || content == null || "".equals(content)) {
            String html = HtmlGenerator.getMessagePage("提交的标题或者正文为空!",
                    "article");
            resp.getWriter().write(html);
            return;
        }
        // 3. 把数据插入到数据库中.
        ArticleDao articleDao = new ArticleDao();
        Article article = new Article();
        article.setArticleTitle(title);
        article.setArticleContent(content);
        article.setUserId(user.getUserId());
        articleDao.add(article);
        // 4. 返回一个插入成功的页面.
        String html = HtmlGenerator.getMessagePage("发布成功！","article");
        resp.getWriter().write(html);
        return;
    }
}

8)删除文章

请求:
GET /deleteArticle?articleld= 1

import Dao.ArticleDao;
import Entity.Article;
import Entity.User;
import View.HtmlGenerator;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

public class DeleteArticleServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=utf-8");
        // 1. 验证用户的登陆状态, 如果未登陆, 肯定不能删除.
        HttpSession httpSession = req.getSession(false);
        if(httpSession == null){
            String html = HtmlGenerator.getMessagePage("您尚未登录！","login.html");
            resp.getWriter().write(html);
            return;
        }
        User user = (User) httpSession.getAttribute("user");

        // 2. 读取请求内容, 获取到要删除的文章 id
        String articleIdStr = req.getParameter("articleId");
        if (articleIdStr == null || "".equals(articleIdStr)) {
            String html = HtmlGenerator.getMessagePage("要删除的文章 id 有误!",
                    "article");
            resp.getWriter().write(html);
            return;
        }
        // 3. 根据文章 id 查找到该文章的作者. 当前用户如果就是作者, 才能删除, 否则删除失败.
        ArticleDao articleDao = new ArticleDao();
        Article article = articleDao.findArticleByArticleId(Integer.parseInt(articleIdStr));
        if(article.getUserId() != user.getUserId()){
            String html = HtmlGenerator.getMessagePage("您只能删除自己的文章!",
                    "article");
            resp.getWriter().write(html);
            return;
        }
        // 4. 真正执行数据库删除操作
        articleDao.deleteArticle(Integer.parseInt(articleIdStr));
        // 5. 返回一个 "删除成功" 的页面.
        String html = HtmlGenerator.getMessagePage("删除成功!",
                "article");
        resp.getWriter().write(html);

    }
}

响应:
返回一个提示页面,告诉用户删除成功还是失败.

import Entity.Article;
import Entity.User;

import java.util.List;

public class HtmlGenerator {
    public static String getMessagePage(String message, String nextUrl) {
        StringBuilder stringBuilder = new StringBuilder();
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("");

        stringBuilder.append("
");
        stringBuilder.append(message);
        stringBuilder.append("
");

        stringBuilder.append(String.format(" 点击这里进行跳转 ",
                nextUrl));

        stringBuilder.append("");
        stringBuilder.append("");

        return stringBuilder.toString();

    }
    // 按照字符串拼装的方式, 生成 html
    public static String getArticleListPage(List<Article> articles, User user) {
        StringBuilder stringBuilder = new StringBuilder();
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("");

        stringBuilder.append("
 欢迎您!    " + user.getUserName() + "
");
        stringBuilder.append("
");
        // 要有一个文章列表. 显示每个文章的标题.
        for (Article article : articles) {
            stringBuilder.append(String.format("
  %s " +
                            " 删除 
",
                    article.getArticleId(), article.getArticleTitle(), article.getArticleId()));
        }
        stringBuilder.append("
");
        stringBuilder.append(String.format("
当前共有博客 %d 篇
", articles.size()));

        // 在这里新增发布文章的区域
        stringBuilder.append("
 发布文章 
");
        stringBuilder.append("
");
        stringBuilder.append("
");
        stringBuilder.append("");
        stringBuilder.append("
");
        stringBuilder.append("");
        stringBuilder.append("
");
        stringBuilder.append("");
        stringBuilder.append(""
);
        stringBuilder.append("
");

        stringBuilder.append("");
        stringBuilder.append("");
        return stringBuilder.toString();
    }


    public static String getArticleDetailPage(Article article, User user, User author) {
        StringBuilder stringBuilder = new StringBuilder();
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("");
        stringBuilder.append("
 欢迎您! " + user.getUserName() + "
");
        stringBuilder.append("
");

        stringBuilder.append(String.format("
%s
", article.getArticleTitle()));
        stringBuilder.append(String.format("
作者: %s
", author.getUserName()));
        // 构造正文的地方.
        // HTML 中本来就不是用 \n 表示换行的.
        stringBuilder.append(String.format("
%s
", article.getArticleContent()
                .replace("\n", "
")));

        stringBuilder.append("");
        stringBuilder.append("");
        return stringBuilder.toString();
    }
}

成果

关于前端大家可以自己套模板就好啦