空指針在GAE更新實體

安卓APP->通話endpoint-> getPerson（電子郵件）
端點返回我1個個人物P
我在Android上使用這個對象應用程序並更改一些值。
安卓APP->通話endpoint->的updatePerson（P）

我得到這個錯誤從服務器：

 

    com.google.api.server.spi.SystemService invokeServiceMethod: null 
    java.lang.NullPointerException 
     at com.google.appengine.api.datastore.Key.getAppId(Key.java:279) 
     at com.google.appengine.api.datastore.KeyTranslator.convertToPb(KeyTranslator.java:50) 
     at com.google.appengine.api.datastore.EntityTranslator.convertToPb(EntityTranslator.java:48) 
     at com.google.appengine.api.datastore.AsyncDatastoreServiceImpl$4.toPb(AsyncDatastoreServiceImpl.java:178) 
     at com.google.appengine.api.datastore.AsyncDatastoreServiceImpl$4.toPb(AsyncDatastoreServiceImpl.java:155) 
     at com.google.appengine.api.datastore.Batcher$BatchIterator.(Batcher.java:180) 
     at com.google.appengine.api.datastore.Batcher$2.(Batcher.java:317) 
     at com.google.appengine.api.datastore.Batcher.getBatches(Batcher.java:317) 
     at com.google.appengine.api.datastore.AsyncDatastoreServiceImpl.doBatchPut(AsyncDatastoreServiceImpl.java:365) 
     at com.google.appengine.api.datastore.BaseAsyncDatastoreServiceImpl.put(BaseAsyncDatastoreServiceImpl.java:293) 
     at com.google.appengine.api.datastore.BaseAsyncDatastoreServiceImpl.put(BaseAsyncDatastoreServiceImpl.java:239) 
     at com.google.appengine.api.datastore.DatastoreServiceImpl.put(DatastoreServiceImpl.java:61) 
     at com.google.appengine.datanucleus.WrappedDatastoreService.put(WrappedDatastoreService.java:112) 
     at com.google.appengine.datanucleus.EntityUtils.putEntitiesIntoDatastore(EntityUtils.java:766) 
     at com.google.appengine.datanucleus.DatastorePersistenceHandler.insertObjectsInternal(DatastorePersistenceHandler.java:314) 
     at com.google.appengine.datanucleus.DatastorePersistenceHandler.insertObject(DatastorePersistenceHandler.java:218) 
     at org.datanucleus.state.JDOStateManager.internalMakePersistent(JDOStateManager.java:2381) 
     at org.datanucleus.state.JDOStateManager.flush(JDOStateManager.java:3778) 
     at org.datanucleus.ObjectManagerImpl.flushInternalWithOrdering(ObjectManagerImpl.java:3888) 
     at org.datanucleus.ObjectManagerImpl.flushInternal(ObjectManagerImpl.java:3811) 
     at org.datanucleus.ObjectManagerImpl.flush(ObjectManagerImpl.java:3751) 
     at org.datanucleus.ObjectManagerImpl.preCommit(ObjectManagerImpl.java:4141) 
     at org.datanucleus.ObjectManagerImpl.transactionPreCommit(ObjectManagerImpl.java:428) 
     at org.datanucleus.TransactionImpl.internalPreCommit(TransactionImpl.java:398) 
     at org.datanucleus.TransactionImpl.commit(TransactionImpl.java:287) 
     at org.datanucleus.ObjectManagerImpl.close(ObjectManagerImpl.java:1090) 
     at org.datanucleus.api.jpa.JPAEntityManager.close(JPAEntityManager.java:193)

是不是從數據存儲檢索相同的對象？

來源

2014-11-14 cisk

你可以發佈相關端點api類方法與註釋，以及調用這些函數的android代碼？在invokeservicemethod上獲得一個空指針異常看起來像你調用的API方法不存在，所以它可能被註釋/調用不正確。 – Nick 2014-12-18 22:43:30

您可以將您的主鍵

@Id 
@GeneratedValue(strategy = GenerationType.IDENTITY) 
private Long id;

如果您正在使用

@Id 
@GeneratedValue(strategy = GenerationType.IDENTITY) 
private Key key;

，並再次檢查。

來源

2014-12-19 12:20:04

是否有效？這是一個被接受的答案嗎？ – 2014-12-24 05:21:14

這很好，謝謝 – cisk 2015-01-07 11:12:46

空指針在GAE更新實體

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