在jsp中应用MVC模型
在这里通过一个例子来把MVC的思路理清一下;M:即模型层;V:即视图层;C:即控制层;
在jsp中;jsp页面是视图层。而javabean是模型层,Servlet是控制层:
比如我在数据里有一个文章的表,表的字段有:Artical_Id,Artical_Name ,Artical_Content,Artical_Date,Artical_Glancenumber,ArticalTypel_Id ,User_Id,Artical_Character
创建一个javabean类来封装表的字段;
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package com.yxq.valuebean; import java.util.Date; public class Model_Artical { private Integer Artical_Id; private String Artical_Name ; private String Artical_Content; private Date Artical_Date ; private Integer Artical_Glancenumber ; private Integer ArticalTypel_Id ; private Integer User_Id; private String Artical_Character; public String getArtical_Character() { return Artical_Character; } public String getArtical_Character(int number) { if(Artical_Character.length()>30){ return Artical_Character.substring(0, number); } return Artical_Character; } public void setArtical_Character(String artical_Character) { Artical_Character = artical_Character; } public Integer getArtical_Id() { return Artical_Id; } public void setArtical_Id(Integer artical_Id) { Artical_Id = artical_Id; } public String getArtical_Name() { return Artical_Name; } public void setArtical_Name(String artical_Name) { Artical_Name = artical_Name; } public String getArtical_Content() { return Artical_Content; } public void setArtical_Content(String artical_Content) { Artical_Content = artical_Content; } public Date getArtical_Date() { return Artical_Date; } public void setArtical_Date(Date artical_Date) { Artical_Date = artical_Date; } public Integer getArtical_Glancenumber() { return Artical_Glancenumber; } public void setArtical_Glancenumber(Integer artical_Glancenumber) { Artical_Glancenumber = artical_Glancenumber; } public Integer getArticalTypel_Id() { return ArticalTypel_Id; } public void setArticalTypel_Id(Integer articalTypel_Id) { ArticalTypel_Id = articalTypel_Id; } public Integer getUser_Id() { return User_Id; } public void setUser_Id(Integer user_Id) { User_Id = user_Id; } }
jsp页面中请求Servlet,在某个Servlet里这样写:
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package com.yxq.servlet; import java.io.IOException; import java.io.PrintWriter; import java.util.Date; import java.util.List; import javax.servlet.RequestDispatcher; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import com.yxq.dao.ArticalDao; import com.yxq.dao.ArticaltypeDao; import com.yxq.dao.UserDao; import com.yxq.toolsbean.Mytools; import com.yxq.valuebean.Model_Artical; import com.yxq.valuebean.Model_ArticalType; public class ArticleServlet extends HttpServlet { public ArticleServlet() { super(); } public void destroy() { super.destroy(); // Just puts "destroy" string in log // Put your code here } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); String action = request.getParameter("action"); if(action ==null){ action =""; } if(action.equals("read")){ System.out.println("方法"); this.readArticle(request, response); } if(action.equals("add")){ this.addArticle(request, response); } if(action.equals("delete")){ this.deleteArticle(request, response); } if(action.equals("modify")){ this.modifyArticle(request, response); } } public void init() throws ServletException { } public void readArticle(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{ HttpSession session = request.getSession(); String strId = request.getParameter("id"); int id =Mytools.strToint(strId); System.out.println(id); ArticalDao articaldao = new ArticalDao(); Model_Artical artical = null; UserDao userid = new UserDao(); try { artical= articaldao.queryArticleSingle(id); Integer userid1 = artical.getUser_Id(); String authorname = userid.getusername(userid1); request.setAttribute("authorname",authorname); session.setAttribute("artical",artical); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } RequestDispatcher rd = request.getRequestDispatcher("/front/ArticleSingle.jsp"); rd.forward(request, response); } public void addArticle(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{ request.setCharacterEncoding("utf-8"); ArticalDao articledao = new ArticalDao(); Model_Artical article =new Model_Artical(); String articlecontent , articletitle; try{ articlecontent= request.getParameter("articlecontent"); articletitle = request.getParameter("articletitle"); article.setArtical_Content(articlecontent); article.setArtical_Glancenumber(0); article.setArtical_Name(articletitle); article.setArticalTypel_Id(1); article.setUser_Id(1); article.setArtical_Date(new Date()); articledao.operattionArtical("add", article); }catch(Exception e){ e.printStackTrace(); System.out.println("获取表单信息出错"); } response.sendRedirect(request.getContextPath()+"/admin/MyJsp.jsp"); } /*删除文章*/ public void deleteArticle(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{ String strId = request.getParameter("id"); int id =Mytools.strToint(strId); System.out.println("删除文章的id"+id); System.out.print("删除文章"); ArticalDao articaldao = new ArticalDao(); try { articaldao.deleteartical(id); } catch (Exception e) { // TODO Auto-generated catch block System.out.println("删除文章出错"); e.printStackTrace(); } response.sendRedirect(request.getContextPath()+"/admin/admin.jsp"); } /*修改文章*/ public void modifyArticle(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{ String strId = request.getParameter("id"); int id =Mytools.strToint(strId); System.out.println("修改文章的id"+id); System.out.print("修改文章"); ArticalDao articaldao = new ArticalDao(); Model_Artical artical = null; ArticaltypeDao articaltypedao = new ArticaltypeDao(); try { artical= articaldao.queryArticleSingle(id); request.setAttribute("artical",artical); request.setAttribute("articalid",id); List<Model_ArticalType> articaltype = articaltypedao.query(); request.setAttribute("articletypelist",articaltype); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } RequestDispatcher rd = request.getRequestDispatcher("/admin/modifySingle.jsp"); rd.forward(request, response); } }
剩下的模型层要根据自己的实际情况写。