How to use Java to implement the site subtitle function of CMS system-javaTutorial-php.cn

How to use Java to implement the site subtitle function of CMS system

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Release： 2023-08-06 09:18:12

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How to use Java to implement the site subtitle function of the CMS system

With the popularity of the Internet, the CMS system (content management system) plays an increasingly important role. The site subtitle function has become an important part of improving user experience. This article will introduce how to use Java to implement the site subtitle function of the CMS system and provide corresponding code examples.

Subtitles refer to a way of displaying information in text form on website pages. It can be used in various scenarios, such as displaying website announcements, important notifications, event information, etc. When implementing the site subtitle function, we need to consider the following aspects: content management, display method and automatic refresh.

First of all, it is necessary to manage subtitle content. We can use a database to store subtitle data and provide corresponding addition, deletion, modification and query interfaces. The following is a simple sample code:

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

public class SubtitleDAO {
    private static final String URL = "jdbc:mysql://localhost:3306/cms";
    private static final String USERNAME = "root";
    private static final String PASSWORD = "password";
    
    public void saveSubtitle(String content) {
        try (Connection conn = DriverManager.getConnection(URL, USERNAME, PASSWORD)) {
            String sql = "INSERT INTO subtitle(content) VALUES(?)";
            PreparedStatement stmt = conn.prepareStatement(sql);
            stmt.setString(1, content);
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
    public String getSubtitle() {
        String subtitle = "";
        try (Connection conn = DriverManager.getConnection(URL, USERNAME, PASSWORD)) {
            String sql = "SELECT content FROM subtitle";
            PreparedStatement stmt = conn.prepareStatement(sql);
            ResultSet rs = stmt.executeQuery();
            while (rs.next()) {
                subtitle = rs.getString("content");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return subtitle;
    }
    
    public void deleteSubtitle() {
        try (Connection conn = DriverManager.getConnection(URL, USERNAME, PASSWORD)) {
            String sql = "DELETE FROM subtitle";
            PreparedStatement stmt = conn.prepareStatement(sql);
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

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Next, you need to implement the display method of subtitle content. A common way is to display a fixed-position subtitle bar at the top or bottom of the website page. We can achieve this effect with the help of HTML and CSS. The following is a simple sample code:

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>CMS系统站点字幕功能示例</title>
    <style>
        .subtitle {
            position: fixed;
            width: 100%;
            height: 30px;
            line-height: 30px;
            background-color: #e0e0e0;
            text-align: center;
            font-size: 14px;
            color: #333;
            top: 0;
            left: 0;
        }
    </style>
</head>
<body>
    <div class="subtitle">
        <span id="content"></span>
    </div>
    
    <script>
        function refreshSubtitle() {
            // 使用Ajax从服务器获取字幕内容
            var xhr = new XMLHttpRequest();
            xhr.open('GET', '/getSubtitle', true);
            xhr.onreadystatechange = function() {
                if (xhr.readyState == 4 && xhr.status == 200) {
                    // 更新页面上的字幕内容
                    document.getElementById('content').textContent = xhr.responseText;
                }
            };
            xhr.send();
        }
        
        // 每隔一段时间自动刷新字幕内容
        setInterval(refreshSubtitle, 5000);
    </script>
</body>
</html>

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Finally, automatic refresh of subtitle content needs to be implemented. We can use JavaScript timers to regularly obtain the latest subtitle content from the server and update the display on the page. The following is a simple sample code:

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

@WebServlet("/getSubtitle")
public class SubtitleServlet extends HttpServlet {
    private SubtitleDAO subtitleDAO = new SubtitleDAO();
    
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("text/plain");
        resp.setCharacterEncoding("UTF-8");
        
        // 从数据库获取最新的字幕内容
        String subtitle = subtitleDAO.getSubtitle();
        
        resp.getWriter().write(subtitle);
    }
}

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To summarize, completing the site subtitle function of the CMS system requires the realization of three aspects: content management, display method and automatic refresh. By using Java's database operations and Servlet technology, combined with HTML, CSS and JavaScript, we can easily implement this function. I hope the sample code in this article can help readers better understand and practice.

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