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GAE - 未找到元数据

javaeclipsegoogle-app-enginejsp
3
我希望您能够在App Engine中显示表格中的数据：
我的显示方法：
    public List<User> getAllEntries() {
        PersistenceManager pm = PMF.get().getPersistenceManager();
        Query q = pm.newQuery(User.class);
//      q.setOrdering("date desc");
        List<User> results = null;

        try {
            results = (List<User>) q.execute();
            if (!results.isEmpty()) {
                return results;
            }   
        } finally {
            q.closeAll();
            pm.close();
        }

        return results;
    }

这里我想在表格中显示它：

    <table class="table">
                    <thead>
                        <tr>
                            <th>#</th>
                            <th>Email</th>
                            <th>Password</th>
                            <th>Date</th>
                            <th style="width: 36px;"></th>
                        </tr>
                    </thead>
                    <tbody>
                        <%
                            for (int i = 0; i < userDAO.getAllEntries().size(); i++) {
                                                                %>
                        <tr>
                            <td><%=userDAO.getAllEntries().get(i).getId()%></td>
                            <td><%=userDAO.getAllEntries().get(i).getEmail()%></td>
                            <td><%=userDAO.getAllEntries().get(i).getPassword()%></td>
                            <td><%=userDAO.getAllEntries().get(i).getWhen()%></td>
                        </tr>
                        <%
                            }
                        %>

                    </tbody>
                </table>

我的领域对象：
@PersistenceCapable(identityType=IdentityType.APPLICATION)
public class User {

    @PrimaryKey
    @Persistent(valueStrategy=IdGeneratorStrategy.IDENTITY)
    private long id;

    //  @Persistent
    //  private String name;

    @Persistent
    private String email;

    @Persistent
    private String password;

    @Persistent
    private Date when;

    public User() {
        super();
    }

当我运行它时，我得到：
   No meta-data for member named date on class gaeTrader2.server.domain.User.  Are you sure you provided the correct member name in your query?

我的代码有什么问题。所有元数据都设置了吗？
看这里：
@Persistent
private Date when;

UPDATE

Caused by:

javax.jdo.JDOFatalUserException: No meta-data for member named date on class gaeTrader2.server.domain.User.  Are you sure you provided the correct member name in your query?
    at org.datanucleus.api.jdo.NucleusJDOHelper.getJDOExceptionForNucleusException(NucleusJDOHelper.java:498)
    at org.datanucleus.api.jdo.JDOQuery.execute(JDOQuery.java:230)
    at gaeTrader2.server.dao.DAOUser.getAllEntries(DAOUser.java:44)
    at org.apache.jsp.centralcommand_jsp._jspService(centralcommand_jsp.java:199)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
    at com.google.appengine.tools.development.PrivilegedJspServlet.access$101(PrivilegedJspServlet.java:23)
    at com.google.appengine.tools.development.PrivilegedJspServlet$2.run(PrivilegedJspServlet.java:59)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.google.appengine.tools.development.PrivilegedJspServlet.service(PrivilegedJspServlet.java:57)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
    at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:123)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:61)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:97)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
    at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:94)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:409)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
NestedThrowablesStackTrace:
No meta-data for member named date on class gaeTrader2.server.domain.User.  Are you sure you provided the correct member name in your query?
org.datanucleus.exceptions.NucleusFatalUserException: No meta-data for member named date on class gaeTrader2.server.domain.User.  Are you sure you provided the correct member name in your query?
    at com.google.appengine.datanucleus.query.DatastoreQuery.noMetaDataException(DatastoreQuery.java:1267)
    at com.google.appengine.datanucleus.query.DatastoreQuery.getSortProperty(DatastoreQuery.java:670)
    at com.google.appengine.datanucleus.query.DatastoreQuery.addSorts(DatastoreQuery.java:637)
    at com.google.appengine.datanucleus.query.DatastoreQuery.compile(DatastoreQuery.java:249)
    at com.google.appengine.datanucleus.query.JDOQLQuery.performExecute(JDOQLQuery.java:158)
    at org.datanucleus.store.query.Query.executeQuery(Query.java:1789)
    at org.datanucleus.store.query.Query.executeWithArray(Query.java:1666)
    at org.datanucleus.store.query.Query.execute(Query.java:1639)
    at org.datanucleus.api.jdo.JDOQuery.execute(JDOQuery.java:221)
    at gaeTrader2.server.dao.DAOUser.getAllEntries(DAOUser.java:44)
    at org.apache.jsp.centralcommand_jsp._jspService(centralcommand_jsp.java:199)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
    at com.google.appengine.tools.development.PrivilegedJspServlet.access$101(PrivilegedJspServlet.java:23)
    at com.google.appengine.tools.development.PrivilegedJspServlet$2.run(PrivilegedJspServlet.java:59)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.google.appengine.tools.development.PrivilegedJspServlet.service(PrivilegedJspServlet.java:57)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
    at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:123)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:61)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:97)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
    at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:94)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:409)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

Caused by:

No meta-data for member named date on class gaeTrader2.server.domain.User.  Are you sure you provided the correct member name in your query?
org.datanucleus.exceptions.NucleusFatalUserException: No meta-data for member named date on class gaeTrader2.server.domain.User.  Are you sure you provided the correct member name in your query?
    at com.google.appengine.datanucleus.query.DatastoreQuery.noMetaDataException(DatastoreQuery.java:1267)
    at com.google.appengine.datanucleus.query.DatastoreQuery.getSortProperty(DatastoreQuery.java:670)
    at com.google.appengine.datanucleus.query.DatastoreQuery.addSorts(DatastoreQuery.java:637)
    at com.google.appengine.datanucleus.query.DatastoreQuery.compile(DatastoreQuery.java:249)
    at com.google.appengine.datanucleus.query.JDOQLQuery.performExecute(JDOQLQuery.java:158)
    at org.datanucleus.store.query.Query.executeQuery(Query.java:1789)
    at org.datanucleus.store.query.Query.executeWithArray(Query.java:1666)
    at org.datanucleus.store.query.Query.execute(Query.java:1639)
    at org.datanucleus.api.jdo.JDOQuery.execute(JDOQuery.java:221)
    at gaeTrader2.server.dao.DAOUser.getAllEntries(DAOUser.java:44)
    at org.apache.jsp.centralcommand_jsp._jspService(centralcommand_jsp.java:199)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
    at com.google.appengine.tools.development.PrivilegedJspServlet.access$101(PrivilegedJspServlet.java:23)
    at com.google.appengine.tools.development.PrivilegedJspServlet$2.run(PrivilegedJspServlet.java:59)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.google.appengine.tools.development.PrivilegedJspServlet.service(PrivilegedJspServlet.java:57)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
    at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:123)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:61)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:97)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
    at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:94)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:409)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
1个回答
0

你是否曾在你的领域对象上有一个名为“date”的字段？我因为删除了一个字段而遇到了类似的问题。当我重新启动应用引擎实例时，错误消失了。

要做到这一点，打开Google Dev Console，选择你的项目，然后转到App Engine > Instances，选择适当的版本并点击“Shutdown”。下次你的应用程序收到请求时，它将重新启动实例，问题应该就解决了。在我的情况下，那个错误隐藏了一个不同的错误，当我再次查看日志时，它向我展示了我的代码无法工作的真正原因。

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