代码

<%@ page contentType="text/html;charset=UTF-8" language="Java" %><%@ page import="Java.util.List" %>
<%@ page import="Javax.jdo.PersistenceManager" %>
<%@ page import="com.Google.appengine.api.users.User" %>
<%@ page import="com.Google.appengine.api.users.UserService" %>
<%@ page import="com.Google.appengine.api.users.UserServiceFactory" %>
<%@ page import="guestbook.Greeting" %>
<%@ page import="guestbook.PMF" %>

<%
UserService userService = UserServiceFactory.getUserService();
User user = userService.getCurrentUser();
if (user != null) {
%>

Hello, <%= user.getNickname() %>! (You can
sign'>http://new.51cto.com/wuyou/<%=%20userService.createLogoutURL(request.getRequestURI())%20%>">sign out.)
<%
} else {
%>

Hello!
Sign'>http://new.51cto.com/wuyou/<%=%20userService.createLoginURL(request.getRequestURI())%20%>">Sign in
to include your name with greetings you post.
<%
}
%>
<%
PersistenceManager pm = PMF.get().getPersistenceManager();
String query = "select from " + Greeting.class.getName() + " order by date desc range 0,5";
List greetings = (List) pm.newQuery(query).execute();
if (greetings.isEmpty()) {
%>

The guestbook has no messages.
<%
} else {
for (Greeting g : greetings) {
if (g.getAuthor() == null) {
%>

An anonymous person wrote:
<%
} else {
%>

<%= g.getAuthor().getNickname() %>wrote:
<%
}
%>


<%= g.getContent() %>
<%
}
}
pm.close();
%>