用过滤器解决MVC添加书本信息时的乱码问题

一：View addBook.jsp

 1 <%@page language="java" contentType="text/html; charset=utf-8"
 2     pageEncoding="utf-8" import="java.util.*" import="nuc.sw.EL.bean.EL"%>
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 4 <html>
 5 <head>
 6 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
 7 <title>Insert title here</title>
 8 </head>
 9 <body>
10 <form action="ELServlet" method="post">
11  <table  align="left" >
12  <tr>
13   <td>书名:</td>
14   <td><input type="text" name="bookName"></td>
15  </tr>
16  <tr>
17   <td>作者:</td>
18   <td><input type="text" name="authorName"></td>
19  </tr>
20  <tr>
21   <td>定价:</td>
22   <td><input type="text" name="bookPrice"></td>
23  </tr>
24  <tr>
25   <td><input type="submit" value="添加"></td>
26  </tr>
27 </table>
28 </form>
29 </body>
30 </html>

二：Model nuc.sw.EL.bean EL.java

 1 package nuc.sw.EL.bean;
 2 
 3 public class EL {
 4   private String bookName;
 5   private String authorName;
 6   private float bookPrice;
 7 public String getBookName() {
 8     return bookName;
 9 }
10 public void setBookName(String bookName) {
11     this.bookName = bookName;
12 }
13 public String getAuthorName() {
14     return authorName;
15 }
16 public void setAuthorName(String authorName) {
17     this.authorName = authorName;
18 }
19 public Float getBookPrice() {
20     return bookPrice;
21 }
22 public void setBookPrice(Float bookPrice) {
23     this.bookPrice = bookPrice;
24 }
25   
26 }

三：Control nuc.sw.EL.servlet ELServlet.java

 1 package nuc.sw.EL.servlet;
 2 
 3 import java.io.IOException;
 4 import java.util.ArrayList;
 5 import java.util.List;
 6 
 7 import javax.servlet.ServletException;
 8 import javax.servlet.http.HttpServlet;
 9 import javax.servlet.http.HttpServletRequest;
10 import javax.servlet.http.HttpServletResponse;
11 
12 import nuc.sw.EL.bean.EL;
13 
14 /**
15  * Servlet implementation class ELServlet
16  */
17 public class ELServlet extends HttpServlet {
18     private static final long serialVersionUID = 1L;
19        
20     /**
21      * @see HttpServlet#HttpServlet()
22      */
23     public ELServlet() {
24         super();
25         // TODO Auto-generated constructor stub
26     }
27 
28     /**
29      * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
30      */
31     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
32         // TODO Auto-generated method stub
33         response.getWriter().append("Served at: ").append(request.getContextPath());
34     }
35 
36     /**
37      * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
38      */
39     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
40         // TODO Auto-generated method stub
41         //doGet(request, response);
42         EL el=new EL();
43         el.setBookName(request.getParameter("bookName"));
44         el.setAuthorName(request.getParameter("authorName"));
45         el.setBookPrice(Float.parseFloat(request.getParameter("bookPrice")));
46         //request.setAttribute("el", el);
47         List<EL> list;
48         if(request.getSession().getAttribute("booklist")==null){
49             list= new ArrayList<EL>();
50             list.add(el);
51         }
52         else{
53             list=(ArrayList<EL>)request.getSession().getAttribute("booklist");
54             list.add(el);
55         }
56         
57         request.getSession().setAttribute("booklist", list);
58         request.getRequestDispatcher("showBookInfo.jsp").forward(request, response);
59         //request.getRequestDispatcher("addBook.jsp").forward(request, response);
60     }
61 
62 }

四：显示书本信息 showBookInfo.jsp

 1 <%@page language="java" contentType="text/html; charset=utf-8"
 2     pageEncoding="utf-8" import="java.util.*,nuc.sw.EL.bean.EL"%>
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 4 <html>
 5 <head>
 6 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
 7 <title>Insert title here</title>
 8 </head>
 9 <body>
10     <table  align="right" border="1">
11          <caption>全部书籍信息</caption>
12          <tr>
13           <td>书名:</td>
14           <td>作者:</td>
15          <td>定价:</td>
16   </tr>
17   <% 
18         Iterator<EL> iter=((ArrayList<EL>)session.getAttribute("booklist")).iterator();  
19         while(iter.hasNext()){
20           pageContext.setAttribute("book",iter.next());
21    %>
22      
23     <tr>
24       <td>${book.bookName} </td>
25       <td>${book.authorName} </td>
26       <td>${book.bookPrice} </td>
27    </tr>    
28 <%
29     }
30 %>
31 
32 </table>
33 <a href="addBook.jsp">继续添加</a>
34 </body>
35 </html>

五：设置汉字乱码 nuc.sw.book.filter EncodingFilter.java

 1 package nuc.sw.book.filter;
 2 
 3 import java.io.IOException;
 4 import javax.servlet.Filter;
 5 import javax.servlet.FilterChain;
 6 import javax.servlet.FilterConfig;
 7 import javax.servlet.ServletException;
 8 import javax.servlet.ServletRequest;
 9 import javax.servlet.ServletResponse;
10 
11 /**
12  * Servlet Filter implementation class EncodingFilter
13  */
14 public class EncodingFilter implements Filter {
15 
16     /**
17      * Default constructor. 
18      */
19     public EncodingFilter() {
20         // TODO Auto-generated constructor stub
21     }
22 
23     /**
24      * @see Filter#destroy()
25      */
26     public void destroy() {
27         // TODO Auto-generated method stub
28     }
29 
30     /**
31      * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
32      */
33     public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
34         // TODO Auto-generated method stub
35         // place your code here
36 
37         // pass the request along the filter chain
38         request.setCharacterEncoding("utf-8");
39         chain.doFilter(request, response);
40     }
41 
42     /**
43      * @see Filter#init(FilterConfig)
44      */
45     public void init(FilterConfig fConfig) throws ServletException {
46         // TODO Auto-generated method stub
47     }
48 
49 }

六：运行结果