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

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;import bdqn.newsManageServlet.entity.categoryTB;public class doCategoryaddServlet 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();request.setCharacterEncoding("utf-8");String name=request.getParameter("categoryName");if(name==null||name.equals("")){request.setAttribute("ermsg", "类别名称不能为空！");request.getRequestDispatcher("addCategory.jsp").forward(request, response);return;}//调用访问数据称 //categoryTBDao cdao=new categoryTBDaoImpl(); categoryTBService cgService=new categoryTBServiceImpl();//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(cgService.getCateByName(name)!=null){request.setAttribute("ermsg", "类别名已存在！");request.getRequestDispatcher("adminManage/addCategory.jsp").forward(request, response);return;}//3.不重复，实现添加功能，提示添加成功，跳转到管理页面 //先封装实体类categoryTB cate=new categoryTB();cate.setCategoryName(name);int rel=cgService.addCategory(cate);if(rel>0){//添加成功out.print("<script>alert('添加成功');location.href='adminManage/manageTopic.jsp';</script>");}else{request.setAttribute("ermsg", "添加失败");request.getRequestDispatcher("adminManage/addCategory.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}}