Java 为什么我在rDao.insert（log）处遇到未处理的SQL异常？

每当我尝试调用RegisterDao中的insert方法时，Eclipse中就会出现一个“未处理的SQL异常”错误，这迫使我添加一个catch-try块。这总是把我搞得一团糟，因为try-catch使我将结果初始化为null。。。我不能让它工作

LogServlet.java

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


@WebServlet("/LogServlet")
public class LogServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public LogServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

     @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        response.getWriter().append("Served at: ").append(request.getContextPath());
        
     }


@Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    
         
            String id = request.getParameter("id");
            String name = request.getParameter("name");
            String title = request.getParameter("title");
            String date = request.getParameter("date");
            Log log = new Log(id, name, title, date);
        
            RegisterDao rDao = new RegisterDao();
         String result;
        result = rDao.insert(log);
        response.getWriter().print(result);
}
}

RegisterDao.java

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

public class RegisterDao {
    

    private static final String USERNAME = "dbuser";
    private static final String PASSWORD = "dbpassword";
    private static final String M_CONN_STRING =
            "jdbc:mysql://localhost/loggy";

    
    
    
    public String insert(Log log) throws SQLException {
    
    
        Connection con = DBUtil.getConnection(DBType.MYSQL);
        String result = "Data entered successfully";
        String sql = "insert into logs values(?,?,?,?)";
    
        PreparedStatement ps;
        try {
        ps = con.prepareStatement(sql);
        ps.setString(1, log.getid());
        ps.setString(2, log.getName());
        ps.setString(3, log.getTitle());
        ps.setString(4, log.getDate());
        ps.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            result = "Data not entered";
        }
        return result;
    }

}

---

当您有

catch（SQLException e）

时，为什么有

insert（Log Log）抛出SQLException

？为什么不更改此代码？当我执行抛出操作时，我收到另一个抛出操作，说在连接con=DBUtil.getConnectionKeep

result

之外有一个SQL异常未处理。在

try

中添加

con

、

sql

和

ps

。