新闻发布项目——Servlet类（doDelCategoryServlet ）

package bdqn.newsManageServlet.Servlet;
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 bdqn.newsManageServlet.Service.categoryTBService;
import bdqn.newsManageServlet.Service.Impl.categoryTBServiceImpl;
public class doDelCategoryServlet extends HttpServlet {
  /**
   * Destruction of the servlet. <br>
   */
  public void destroy() {
    super.destroy(); // Just puts "destroy" string in log
    // Put your code here
  }
  /**
   * The doGet method of the servlet. <br>
   *
   * This method is called when a form has its tag value method equals to get.
   * 
   * @param request the request send by the client to the server
   * @param response the response send by the server to the client
   * @throws ServletException if an error occurred
   * @throws IOException if an error occurred
   */
  public void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    response.setContentType("text/html;charset=utf-8");
    PrintWriter out = response.getWriter();
    //获取id
    int id=Integer.parseInt(request.getParameter("cgid"));
    //创建业务逻辑层的对象
    categoryTBService sgService = new categoryTBServiceImpl();
    int rel = sgService.delCategory(id);
    if (rel > 0) {
    //删除成功！
      out.print("<script>alert('删除成功');location.href='adminManage/manageTopic.jsp';</script>");
    } else if(rel==0) {
      //删除失败
      out.print("<script>alert('删除失败，该类别下有新闻，不能删除');location.href='adminManage/manageTopic.jsp';</script>");
    }else{
      //删除失败
      out.print("<script>alert('删除失败，请联系管理员！！！');location.href='adminManage/manageTopic.jsp';</script>");
    }
  }
  /**
   * The doPost method of the servlet. <br>
   *
   * This method is called when a form has its tag value method equals to post.
   * 
   * @param request the request send by the client to the server
   * @param response the response send by the server to the client
   * @throws ServletException if an error occurred
   * @throws IOException if an error occurred
   */
  public void doPost(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    doGet(request, response);
  }
  /**
   * Initialization of the servlet. <br>
   *
   * @throws ServletException if an error occurs
   */
  public void init() throws ServletException {
    // Put your code here
  }
}