Google App Engine JDO 错误

Question

我正在尝试使以下类持久化，并且每当我尝试使其持久化时都会收到 UnexpectedException：

@PersistenceCapable
public class JdoResidence {
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key key;

// Each row should have two columns. [][0] is for last name. [][1] is for first name.
@Persistent
private String [] [] names;

// Address in following format: "12345 Sample St., Indianapolis, IN 12345"
@Persistent
private String address;

// Lot number
@Persistent
private int lotNumber;

// Phone number in following format:
// "(123) 456-7890"
@Persistent
private String phoneNumber;

public JdoResidence(String[][] names, String address, int lotNumber, String phoneNumber) {
    this.names = names;
    this.address = address;
    this.lotNumber = lotNumber;
    this.phoneNumber = phoneNumber;
}

使 JdoResidence 持久化的方法是：

@Override
public boolean addResidence(Residence input) {
    JdoResidence toAdd = new JdoResidence(input.names, input.address, input.lotNumber, input.phoneNumber);
    PersistenceManager pm = PMF.get().getPersistenceManager();
    try {
        pm.makePersistent(toAdd);
    } finally {
        pm.close();
    }
    return true;

}

这是来自 Jetty 的日志：

Dec 21, 2011 10:47:53 PM com.google.appengine.tools.development.ApiProxyLocalImpl log
SEVERE: javax.servlet.ServletContext log: Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract boolean com.woodfielddowns.directory.client.ResidenceDataService.addResidence(com.woodfielddowns.directory.shared.Residence)' threw an unexpected exception: java.lang.IllegalArgumentException: names: [Ljava.lang.String; is not a supported property type.
    at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:385)
    at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:588)
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
    at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
    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$CachedChain.doFilter(ServletHandler.java:1166)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:35)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:60)
    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:122)
    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:78)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:362)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
    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: java.lang.IllegalArgumentException: names: [Ljava.lang.String; is not a supported property type.
    at com.google.appengine.api.datastore.DataTypeUtils.checkSupportedSingleValue(DataTypeUtils.java:184)
    at com.google.appengine.api.datastore.DataTypeUtils.checkSupportedValue(DataTypeUtils.java:149)
    at com.google.appengine.api.datastore.DataTypeUtils.checkSupportedValue(DataTypeUtils.java:123)
    at com.google.appengine.api.datastore.Entity.setProperty(Entity.java:319)
    at org.datanucleus.store.appengine.DatastoreFieldManager.storeObjectField(DatastoreFieldManager.java:847)
    at org.datanucleus.state.AbstractStateManager.providedObjectField(AbstractStateManager.java:1037)
    at com.woodfielddowns.directory.server.JdoResidence.jdoProvideField(JdoResidence.java)
    at com.woodfielddowns.directory.server.JdoResidence.jdoProvideFields(JdoResidence.java)
    at org.datanucleus.state.JDOStateManagerImpl.provideFields(JDOStateManagerImpl.java:2715)
    at org.datanucleus.store.appengine.DatastorePersistenceHandler.insertPreProcess(DatastorePersistenceHandler.java:357)
    at org.datanucleus.store.appengine.DatastorePersistenceHandler.insertObjects(DatastorePersistenceHandler.java:267)
    at org.datanucleus.store.appengine.DatastorePersistenceHandler.insertObject(DatastorePersistenceHandler.java:256)
    at org.datanucleus.state.JDOStateManagerImpl.internalMakePersistent(JDOStateManagerImpl.java:3185)
    at org.datanucleus.state.JDOStateManagerImpl.makePersistent(JDOStateManagerImpl.java:3161)
    at org.datanucleus.ObjectManagerImpl.persistObjectInternal(ObjectManagerImpl.java:1298)
    at org.datanucleus.ObjectManagerImpl.persistObject(ObjectManagerImpl.java:1175)
    at org.datanucleus.jdo.JDOPersistenceManager.jdoMakePersistent(JDOPersistenceManager.java:669)
    at org.datanucleus.jdo.JDOPersistenceManager.makePersistent(JDOPersistenceManager.java:694)
    at com.woodfielddowns.directory.server.ResidenceDataServiceImpl.addResidence(ResidenceDataServiceImpl.java:40)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:104)
    at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:569)
    ... 34 more

关于为什么 String 不是受支持的属性类型的任何想法？

Answer 1

不支持多维数组，可能的解决方案是，

• 您可以将其存储为 ArrayList（或任何其他集合，请参阅文档）
• 或者使用两个不同的列作为名字和姓氏
• 或者将二维数组作为一个 blob。

参考this thread和docs

Answer 2

尝试替换它

@Persistent 
private String [] [] names; 

使用 ArrayList 或嵌入对象

Answer 3

您也可以将其作为序列化持久性 (@Persistent(serialized = "true"))，默认情况下将其存储为 blob！