服务器500错误 invalid method declaration

500 Servlet Exception
E:\jspweb\WEB-INF\classes\ShopCartForm.java:11: invalid method declaration;
return type required
public Book(){}
               ^
1 error
首页  和个别页 出现这个错误 
说方法没有声明？？
附首页：
<%@ page contentType="text/html;charset=GBK" language="java" %>
<%@ page import = "BookStore.*" %>
<%@ page import = "java.util.*" %>
<%
Vector catList = (Vector)session.getAttribute(Constants.BOOK_CAT_LIST_KEY);
Vector bookList = (Vector)session.getAttribute(Constants.BOOK_LIST_KEY);
Book book = null;
BookCat bookCat = null;

SearchStatus schSta = (SearchStatus)session.getAttribute(Constants.BOOK_SEARCH_STATUS_KEY);
%><HTML>
<HEAD><TITLE>书籍查询</TITLE>
<META http-equiv=Content-Type content="text/html; charset=gb2312">
<LINK href="images/new.css" type="text/css" rel=stylesheet>
</HEAD>
<BODY bgcolor="#7387B8"> 
<div align="center">
  <img border="0" src="images/ruanjian.jpg" width="770" height="154" ></div>
<TABLE cellSpacing=0 cellPadding=0 width="788" border=0>
  <TR vAlign=top bgColor=#cbd7f3>
    <TD align=middle width=170 bgColor=#7387B8>
      <br><br>
      <TABLE cellSpacing=0 cellPadding=0 width="90%" align=center border=0>
       <TR> <TD bgcolor="#FFFFFF">
       
    <%if(catList != null ){       for(int i = 0;i < catList.size();i++)
       {  
        bookCat = (BookCat)catList.get(i);
       %>
       
       <a href="bookSearch.do?bookCatId=<%=bookCat.getId()%>&mode=1"><font color="#000000"><%=bookCat.getName()%></font></a><br>       
          <%
         }
      }
      %>
       
         
</TD> </TR>
  </TABLE>
</TD>
    <TD bgColor=#7387B8>
<br>
 <TABLE cellSpacing=0 cellPadding=0 width="90%" align=center border=0 bgColor=#ffffff>
      <TR><TD>
  <FORM action="bookSearch.do" method=post>
  <DIV align=center><font size=2>请输入关键字：<font>
  <INPUT type=hidden name=mode value="2"> 
  <INPUT class=button2 size=12 name=key> 
   <SELECT class=button1 name=field> 
   <OPTION value=1 selected>书名</OPTION> 
   <OPTION  value=2>作者</OPTION> </SELECT> 
  <INPUT type=submit value=搜索 name=Submit> 
<BR><BR></DIV></FORM>
  </TD></TR>
  <TR><TD width="50%" height=20>&nbsp;&nbsp;课程信息总目录：</TD></TR>
  <TR><TD align=right width="48%" height=10>共查到 <%=schSta.getBookCount()%>条记录，显示第<%=schSta.getPageId()+1%>页/总<%=schSta.getPageCount()%>页</TD></TR>
  <TR><TD>
  <table class="txt" cellSpacing="1" cellPadding="1" width="515" align="center" bgColor="#005b4b" border="0">
        <tr bgColor="#bad4a5">
          <td vAlign="top" width="197" bgcolor="#0099CC" align="center"><b>
          <font color="#FFFFFF">书名</font></b></td>
          <td vAlign="top" width="39" bgcolor="#0099CC" align="center"><b>
          <font color="#FFFFFF">定价</font></b></td>
          <td vAlign="top" width="41" bgcolor="#0099CC" align="center"><b>
          <font color="#FFFFFF">会员价</font></b></td>
          <td vAlign="top" width="112" bgcolor="#0099CC" align="center"><b>
          <font color="#FFFFFF">作者</font></b></td>
          <td vAlign="top" width="42" bgcolor="#0099CC" align="center"><b>
          <font color="#FFFFFF">详细</font></b></td>
        </tr>
        
   <%if(bookList != null ){       for(int i = 0;i < bookList.size();i++)
       {  
        book = (Book)bookList.get(i);
      %> <tr bgColor="#ffffff">
          <td width="197" bgColor="#ffffff"><%=book.getName()%></td>
          <td width="39" bgColor="#ffffff">￥<%=book.getPrice()%></td>
          <td width="41" bgColor="#ffffff">￥<%=book.getSalePrice()%></td>
          <td width="112"><%=book.getAuthor()%></td>
          <td vAlign="center" width="42">
          <a href="bookDetail.do?bookId=<%=book.getId()%>">
          <img src="images/view.gif" border="0" width="25" height="25"></a></td>
      <%
         } %>
      
         
          
        </tr> 
<%}
      %>
      </table>
      <p>　<TR height=24>
<TD align=right>| <font color="#999999">
            <a href="bookPage.do?pageId=<%=0%>">首页</a></font> | <font color="#999999">
            <a href="bookPage.do?pageId=<%=schSta.getPageId()-1%>">上页</a></font> | <a href="bookPage.do?pageId=<%=schSta.getPageId()+1%>">下页</a> </TD>
</TR>
<br></TD></TR>
 </TABLE>                              
 <br>
    </TD>
  </TR>
</TABLE>
</body>
</html>

解决方案 »

  1.   

    <html>
    <head>
    <title></title>
    <meta http-equiv="Content-Type" content="text/html; charset=gb2312">
    <link rel="stylesheet" type="text/css" href="images/style.css">
    </head>
    </head>
    <body BGCOLOR="#FFFFFF" leftmargin="0" topmargin="0">
    <div align="center">
      <center>
    <table width="763" border="0" cellpadding="0" cellspacing="0" bgcolor="#336699" height="25" style="border-collapse: collapse" bordercolor="#111111">
      <tr> 
        <td height="25"> 　</td>
      </tr>
      </table>
    </center>
    </div>
    <table width="763" border="0" cellspacing="0" cellpadding="0" align="center">
    <tr><td valign="top">
    <br><br>
    <table border="0" width="90%">
      <form method="post" name="LoginForm" action="login.do">
       <tr>
              <TD>
                <TABLE cellSpacing=0 cellPadding=0 border=0>
                  <TBODY>
                  <TR>
                    <TD>
                    <IMG src="images/book_002.gif" width="161" height="97"></TD>
                    <TD align=middle width=400 
                    background=images/book_004.gif>
                    <IMG 
                      src="H:\Struts交稿\bookstore\images\spacer(1).gif" width="1" height="1"> </TD>
                    <TD>
                    <IMG src="images/book_003.gif" width="142" height="97"> 
                </TD></TR></TBODY></TABLE></TD>
       </tr>
       <tr>
        <td width="100%">
    　</td>
      </tr>
      <tr>
        <td>
          <table border="0" width="100%" align="center">
            <tr>
              <td width="100%" colspan="4" class="small">如果您已注册，请输入您的用户名和密码，订单的完成需要您的信息资料！</td>
            </tr>
            
            <tr>
              <td align="right"><b>用户名:</b></td>
              <td><input type="text" name="username" size="15"></td>
              <td colspan="2">　</td>
            </tr>
            <tr>
              <td align="right"><b>密 码:</b></td>
              <td><input type="password" name="password" size="15"></td>
              <td colspan="2">　</td>
            </tr>
            <tr>
      <td align="right" colspan="3">
              <td>
    <a href="javascript:login()" alt="Check out order">
    <input type="image" src="images/book_012.gif" align="middle" border="0" alt="用户登录" id="image1" name="image1" width="69" height="23"></a></td>
            </tr>
          </table>
        </td>
      </tr>
      <tr>
    <td width="100%" class="small">订单的生成需要您的资料，否则无法为您服务，若您是第一次购物，请您先<a href="userRegister.jsp"><font color="#ff0000">注册</font></a>！</td>
      </tr>
      <tr>
    <td align="center">
    <a href="userRegister.jsp" alt="Check out order">
            <img src="images/book_013.gif" align="middle" border="0" alt="新用户注册" width="69" height="23"></a>
    </td>
      </tr>
      </form>
    </table>
    </td>
    </tr>
    </table>
     <table width="763" border="0" align="center">
      <tr> 
        <td> 
          <hr size=1 width=90%>
        </td>
      </tr>
      <tr> 
        <td height="20"> 
          <div align="center"></div>
        </td>
      </tr>
      </table></body>
    </html>这个页面访问正常
      

  2.   

    弄一个新的jsp.然后一段一段代码贴上去,然后找错误...
    最简单的办法...