jsp留言板系统源码

CREATE TABLE messages (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50),
    content TEXT,
    timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>留言板</title>
</head>
<body>
    <h1>欢迎来到留言板</h1>
    <form action="submit_message.jsp" method="post">
        用户名：<input type="text" name="username"><br>
        留言内容：<textarea name="content" rows="4" cols="50"></textarea><br>
        <input type="submit" value="提交">
    </form>
</body>
</html>

<%@ page import="java.sql.*" %>
<%
    String username = request.getParameter("username");
    String content = request.getParameter("content");

    Connection conn = null;
    PreparedStatement pstmt = null;
    try {
        Class.forName("com.mysql.jdbc.Driver");
        conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "password");
        String sql = "INSERT INTO messages (username, content) VALUES (?, ?)";
        pstmt = conn.prepareStatement(sql);
        pstmt.setString(1, username);
        pstmt.setString(2, content);
        pstmt.executeUpdate();
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        if (pstmt != null) pstmt.close();
        if (conn != null) conn.close();
    }
    response.sendRedirect("view_messages.jsp");
%>

<%@ page import="java.sql.*" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>查看留言</title>
</head>
<body>
    <h1>所有留言</h1>
    <%
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "password");
            stmt = conn.createStatement();
            rs = stmt.executeQuery("SELECT * FROM messages ORDER BY timestamp DESC");
            while (rs.next()) {
    %>
                <p><strong><%= rs.getString("username") %></strong> 于 <%= rs.getTimestamp("timestamp") %> 留言：</p>
                <p><%= rs.getString("content") %></p>
    <%
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (rs != null) rs.close();
            if (stmt != null) stmt.close();
            if (conn != null) conn.close();
        }
    %>
</body>
</html>