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
	}

}