使用javaweb写一个用户注册数据保存至数据库的代码，并要求登录时进行匹配，匹配成功跳至新闻发布系统主页面。

好的，我可以帮您撰写一份JavaWeb用户注册和登录的代码。首先，您需要使用JavaWeb框架，如Spring MVC或Struts2，以及JDBC连接数据库。以下是一个简单的实现：

1. 创建一个用户实体类User，包含以下属性：

public class User {
    private int id;
    private String username;
    private String password;
    // getter和setter方法
}

2. 创建一个Dao类UserDao，实现用户信息的存储和查询：

public class UserDao {
    public void save(User user) {
        Connection conn = null;
        PreparedStatement stmt = null;
        try {
            conn = DBUtil.getConnection();
            String sql = "insert into user (username, password) values (?, ?)";
            stmt = conn.prepareStatement(sql);
            stmt.setString(1, user.getUsername());
            stmt.setString(2, user.getPassword());
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(conn, stmt, null);
        }
    }

    public User findByUsername(String username) {
        Connection conn = null;
        PreparedStatement stmt = null;
        ResultSet rs = null;
        User user = null;
        try {
            conn = DBUtil.getConnection();
            String sql = "select * from user where username=?";
            stmt = conn.prepareStatement(sql);
            stmt.setString(1, username);
            rs = stmt.executeQuery();
            if (rs.next()) {
                user = new User();
                user.setId(rs.getInt("id"));
                user.setUsername(rs.getString("username"));
                user.setPassword(rs.getString("password"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(conn, stmt, rs);
        }
        return user;
    }
}

3. 创建一个控制器类UserController，用于处理用户注册和登录：

public class UserController {
    private UserDao userDao = new UserDao();

    public void register(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String username = request.getParameter("username");
        String password = request.getParameter("password");

        User user = new User();
        user.setUsername(username);
        user.setPassword(password);
        userDao.save(user);

        request.getRequestDispatcher("/login.jsp").forward(request, response);
    }

    public void login(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String username = request.getParameter("username");
        String password = request.getParameter("password");

        User user = userDao.findByUsername(username);
        if (user != null && user.getPassword().equals(password)) {
            HttpSession session = request.getSession();
            session.setAttribute("user", user);
            response.sendRedirect(request.getContextPath() + "/news/list");
        } else {
            request.setAttribute("message", "用户名或密码错误");
            request.getRequestDispatcher("/login.jsp").forward(request, response);
        }
    }
}

4. 创建一个登录页面login.jsp和注册页面register.jsp，以及一个处理注册和登录的Servlet：

public class UserServlet extends HttpServlet {
    private UserController userController = new UserController();

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String path = request.getServletPath();
        if ("/register.jsp".equals(path)) {
            request.getRequestDispatcher("/register.jsp").forward(request, response);
        } else {
            request.getRequestDispatcher("/login.jsp").forward(request, response);
        }
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String path = request.getServletPath();
        if ("/register".equals(path)) {
            userController.register(request, response);
        } else {
            userController.login(request, response);
        }
    }
}

5. 配置web.xml文件，将UserServlet映射到URL路径：

<servlet>
    <servlet-name>UserServlet</servlet-name>
    <servlet-class>com.example.servlet.UserServlet</servlet-class>
</servlet>

<servlet-mapping>
    <servlet-name>UserServlet</servlet-name>
    <url-pattern>/register</url-pattern>
</servlet-mapping>

<servlet-mapping>
    <servlet-name>UserServlet</servlet-name>
    <url-pattern>/login</url-pattern>
</servlet-mapping>

以上是一个简单的JavaWeb用户注册和登录的代码实现，您可以根据自己的需求进行修改和扩展。