在html中的复选框代码:
<body>
<h1>Set Display Preferences</h1><br>
<form action="ListLibraryServlet.view" method="post">
Choose the Items to Display: <input type="checkbox" name="cb1" value="title">Title
<input type="checkbox" name="cb2" value="year">Year
<input type="checkbox" name="cb3" value="genre">Genre<br>
<input type="submit" value="Confirm to Display"/>
</form>
</body>在servlet中的代码: import javax.servlet.http.HttpSession; HttpSession session = request.getSession();
String vTitle = (String) session.getAttribute("cb1");
String vYear =(String) session.getAttribute("cb2");
String vGenre = (String)session.getAttribute("cb3"); if(vTitle.equals("title"))
out.println("<td align='left'>Title</td>");
if(vYear.equals("year"))
out.println("<td align='center'>Year</td>");
if(vGenre.equals("genre"))
out.println("<td align='center'>Genre</td>");
但是用这下面三句测试时
out.println("title: "+vTitle+"<br>");
out.println("year: "+vYear+"<br>");
out.println("genre: "+vGenre);
不管复选框是否选中 得到的结构都是null请各位帮忙解决一下
<body>
<h1>Set Display Preferences</h1><br>
<form action="ListLibraryServlet.view" method="post">
Choose the Items to Display: <input type="checkbox" name="cb1" value="title">Title
<input type="checkbox" name="cb2" value="year">Year
<input type="checkbox" name="cb3" value="genre">Genre<br>
<input type="submit" value="Confirm to Display"/>
</form>
</body>在servlet中的代码: import javax.servlet.http.HttpSession; HttpSession session = request.getSession();
String vTitle = (String) session.getAttribute("cb1");
String vYear =(String) session.getAttribute("cb2");
String vGenre = (String)session.getAttribute("cb3"); if(vTitle.equals("title"))
out.println("<td align='left'>Title</td>");
if(vYear.equals("year"))
out.println("<td align='center'>Year</td>");
if(vGenre.equals("genre"))
out.println("<td align='center'>Genre</td>");
但是用这下面三句测试时
out.println("title: "+vTitle+"<br>");
out.println("year: "+vYear+"<br>");
out.println("genre: "+vGenre);
不管复选框是否选中 得到的结构都是null请各位帮忙解决一下
应该是从request里面取呀 你什么时候存到session里了?
String vYear = request.getParameter("cb2");
String vGenre = request.getParameter("cb3");