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

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.Dao.categoryTBDao;
import bdqn.newsManageServlet.Dao.Impl.categoryTBDaoImpl;
import bdqn.newsManageServlet.entity.categoryTB;
public class doCategoryModifyServlet 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
    request.setCharacterEncoding("utf-8");
    String name=request.getParameter("categoryName");
    int id=0;
    if(request.getParameter("cgid")!=null){
     id=Integer.parseInt(request.getParameter("cgid"));
    }
    //int id=Integer.parseInt(request.getParameter("cgid"));
    //调用访问数据称
     categoryTBDao cdao=new categoryTBDaoImpl();
    //1.判断类别是否重复（在数据库中查询）
    //2.如果有重复，提示错误信息，转发到添加
    if(cdao.getCateByName(name)!=null){
      request.setAttribute("ermsg", "类别名已存在！");
      request.getRequestDispatcher("adminManage/modifyCategory.jsp").forward(request, response);
      return;
    }
    //在数据库中修改
    categoryTB cate=new categoryTB();
    cate.setCategoryName(name);
    cate.setCategoryID(id);
    int rel=cdao.updateCategory(cate);
    if(rel>0){
      //修改成功
      out.print("<script>alert('修改成功');location.href='adminManage/manageTopic.jsp';</script>");
    }else{
      request.setAttribute("ermsg", "修改失败");
      request.getRequestDispatcher("adminManage/modifyCategory.jsp").forward(request, response);
      return;
    }
    
  }
  /**
   * 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
  }
}