```
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.sql.*;
//导入必需的 java 库
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
// 扩展 HttpServlet 类
public class a extends HttpServlet {
private String message;
private String name;
public void init() throws ServletException
{
System.out.println("连接数据库...");
// 执行必需的初始化
message = "Hello World";
String JDBC_DRIVER = "com.mysql.jdbc.Driver";
String DB_URL = "jdbc:mysql://cdb-4gsyv8oy.bj.tencentcdb.com:10071/rdk";
// 数据库的用户名与密码，需要根据自己的设置
String USER = "root";
String PASS = "1qazxsw2";
Connection conn = null;
Statement stmt = null;
System.out.println("123...");
try {
Class.forName("com.mysql.jdbc.Driver");
// 打开链接
System.out.println("连接数据库...");
conn = DriverManager.getConnection(DB_URL, USER, PASS);
// 执行查询
System.out.println(" 实例化Statement对象...");
stmt = conn.createStatement();
String sql;
sql = "SELECT id, name, url FROM websites";
ResultSet rs = stmt.executeQuery(sql);
name = "没有脸上数据库";
while(rs.next()){
// 通过字段检索
int id = rs.getInt("id");
name = rs.getString("name");
String url = rs.getString("url");
// 输出数据
System.out.print("ID: " + id);
System.out.print(", 站点名称: " + name);
System.out.print(", 站点 URL: " + url);
System.out.print("\n");
}
// 完成后关闭
rs.close();
stmt.close();
conn.close();
} catch (Exception e) {
System.out.println(" 实例化Statement对象...");
e.printStackTrace();
}
}
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
// 设置响应内容类型
response.setContentType("text/html");
// 实际的逻辑是在这里
PrintWriter out = response.getWriter();
out.println("<h1>" + message + "</h1>");
out.println("<h1>" + name + "</h1>");
}
public void destroy()
{
// 什么也不做
}
}
```
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