Java 前后端宠物管理系统（ mysql + servlet + jsp ）

package servlet; import java.io.IOException; import java.io.PrintWriter; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.List; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import service.PetService; import service.impl.PetServiceImpl; import entity.pet; public class PetServlet extends HttpServlet { /** * 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 { doPost(request, response); } /** * 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 { request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); response.setContentType("text/html"); PrintWriter out = response.getWriter(); PetService service = new PetServiceImpl(); String opr = request.getParameter("opr"); if ("all".equals(opr)) { List<pet> list = new ArrayList<pet>(); list = service.findAllPets(); request.setAttribute("list", list); request.getRequestDispatcher("index.jsp") .forward(request, response); } else if ("breed".equals(opr)) { List<pet> list = new ArrayList<pet>(); String breed = request.getParameter("pbreed"); if (breed == "" || breed == null) { response.sendRedirect("petServlet?opr=all"); } list = service.findPetsByBreed(breed); request.setAttribute("list", list); request.getRequestDispatcher("index.jsp") .forward(request, response); } else if ("add".equals(opr)) { String pet_name = request.getParameter("pet_name"); String pet_breed = request.getParameter("pet_breed"); String pet_sex = request.getParameter("pet_sex"); String brithday = request.getParameter("brithday"); String description = request.getParameter("description"); boolean flag = true; if (pet_name == "" || pet_name == null) { flag = false; } if (pet_breed == "" || pet_breed == null) { flag = false; } if (pet_sex == "" || pet_sex == null) { flag = false; } if (brithday == "" || brithday == null) { flag = false; } if (flag == false) { response.sendRedirect("pet_add.jsp"); } else { pet p = new pet(); p.setPet_name(pet_name); p.setPet_breed(pet_breed); p.setPet_sex(pet_sex); try { p.setBrithday(new SimpleDateFormat("yyyy-MM-dd") .parse(brithday)); } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } p.setDescription(description); if (service.addPet(p)) { out.print("<script type='text/javascript'>"); out.print("alert('更新成功!');"); out.print("window.location.href='petServlet?opr=all';"); out.print("</script>"); }else{ out.print("<script type='text/javascript'>"); out.print("alert('更新失败!');"); out.print("window.location.href='pet_add.jsp';"); out.print("</script>"); } } } out.flush(); out.close(); } }