DelServlet.java

@WebServlet("/delete")
public class DelServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html; charset=utf-8");
        /*
            刪除指定id的使用者資訊.
         */
        // 獲取到使用者的id.
        String id = request.getParameter("id");

        // 建立UserService物件 , 並呼叫其刪除方法.
        UserService us = new UserService();
        us.deleById(id);

        // 刪除成功之後 , 重定向到findAll頁面 , 更新刪除後的資料.
        response.sendRedirect(request.getContextPath()+"/findAll");
    }
}
 

UserDao.java

public class UserDao {
    // 根據id , 刪除使用者資訊.
    public void deleById(String id) {
        // 建立QueryRunner物件.
        QueryRunner qr = new QueryRunner(DataSourceUtil.getDataSource());
        // 建立sql語句.
        String sql = "delete from user where id=? ";
        // 執行sql
        try {
            qr.update(sql,id);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
  }
 

list.jsp

點選刪除之後 , 彈出確認框 !

<td>
   <a href="javascript:;" onclick="userDel(${user.id})">刪除</a>
</td>

<script type="text/javascript">
        // 當刪除按鈕被點選時,
        function userDel(userid) {
            // 彈出一個確認框 ,
            if (confirm("你確定要刪除嗎?")){
                // 跳轉到刪除的servlet連結.
                location.href = "${pageContext.request.contextPath}/delete?id="+userid;
            }
        }
</script>
 

注: 查詢所有的使用者資訊和具體實現 , 可參考: https://blog.csdn.net/qq_42986107/article/details/83117451