问题描述
我是新来的Android和GAE和面临的问题,同时更新实体从Android应用程序在GAE(后端为Android)(含子对象列表的对象)
情景是:
我已经有保存的数据源中的父对象。然后,我获取该对象,并添加子对象(新建),然后火的更新列表。我的实体是:
父对象
公共类ParentObject {
@Id
@GeneratedValue(策略= GenerationType.IDENTITY)
私有密钥的关键;
私人字符串placeId;
@OneToOne(级联= CascadeType.ALL)
私人列表< ChildObject> childObjects;
公钥getKey(){
返回键;
}
公共无效setkey的(关键的关键){
this.key =键;
}
公共字符串getPlaceId(){
返回placeId;
}
公共无效setPlaceId(字符串placeId){
this.placeId = placeId;
}
公开名单< ChildObject> getChildObject(){
返回childObjects;
}
公共无效setChildObject(名单< ChildObject> childObjects){
this.childObjects = childObjects;
}
}
子对象
@Entity
公共类ChildObject {
@Id
@GeneratedValue(策略= GenerationType.IDENTITY)
私有密钥的关键;
私人字符串USEREMAIL;
公钥getKey(){
返回键;
}
公共无效setkey的(关键的关键){
this.key =键;
}
公共字符串getUserEmail(){
返回USEREMAIL;
}
公共无效setUserEmail(字符串USEREMAIL){
this.userEmail = USEREMAIL;
}
}
和更新的AsyncTask code是
@覆盖
保护ParentObject doInBackground(ParentObject ... PARAMS){
ParentObject parentObj = PARAMS [0];
Parentobjectendpoint.Builder建设者=新Parentobjectendpoint.Builder(
AndroidHttp.newCompatibleTransport(),新JacksonFactory()
空值);
建设者= CloudEndpointUtils.updateBuilder(制造商);
Parentobjectendpoint端点= builder.build();
ParentObject updatedObj;
尝试 {
updatedObj = endpoint.updateParentObject(parentObj).execute();
}赶上(IOException异常E){
// TODO自动生成的catch块
e.printStackTrace();
updatedObj = NULL;
}
返回updatedObj;
}
而我得到的错误是
com.google.api.server.spi.SystemService invokeServiceMethod:空
显示java.lang.NullPointerException
在com.google.appengine.api.datastore.Key.getAppId(Key.java:279)
在com.google.appengine.api.datastore.KeyTranslator.convertToPb(KeyTranslator.java:50)
在com.google.appengine.api.datastore.EntityTranslator.convertToPb(EntityTranslator.java:48)
在com.google.appengine.api.datastore.AsyncDatastoreServiceImpl$4.toPb(AsyncDatastoreServiceImpl.java:178)
在com.google.appengine.api.datastore.AsyncDatastoreServiceImpl$4.toPb(AsyncDatastoreServiceImpl.java:155)
在com.google.appengine.api.datastore.Batcher $ BatchIterator< INIT>(Batcher.java:180)
在com.google.appengine.api.datastore.Batcher $ 2< INIT>(Batcher.java:317)
在com.google.appengine.api.datastore.Batcher.getBatches(Batcher.java:317)
在com.google.appengine.api.datastore.AsyncDatastoreServiceImpl.doBatchPut(AsyncDatastoreServiceImpl.java:365)
在com.google.appengine.api.datastore.BaseAsyncDatastoreServiceImpl.put(BaseAsyncDatastoreServiceImpl.java:293)
在com.google.appengine.api.datastore.BaseAsyncDatastoreServiceImpl.put(BaseAsyncDatastoreServiceImpl.java:239)
在com.google.appengine.api.datastore.DatastoreServiceImpl.put(DatastoreServiceImpl.java:61)
在com.google.appengine.datanucleus.WrappedDatastoreService.put(WrappedDatastoreService.java:112)
在com.google.appengine.datanucleus.EntityUtils.putEntitiesIntoDatastore(EntityUtils.java:766)
在com.google.appengine.datanucleus.DatastorePersistenceHandler.insertObjectsInternal(DatastorePersistenceHandler.java:314)
在com.google.appengine.datanucleus.DatastorePersistenceHandler.insertObject(DatastorePersistenceHandler.java:218)
在org.datanucleus.state.JDOStateManager.internalMakePersistent(JDOStateManager.java:2381)
在org.datanucleus.state.JDOStateManager.flush(JDOStateManager.java:3778)
在org.datanucleus.ObjectManagerImpl.flushInternalWithOrdering(ObjectManagerImpl.java:3888)
在org.datanucleus.ObjectManagerImpl.flushInternal(ObjectManagerImpl.java:3811)
在org.datanucleus.ObjectManagerImpl.flush(ObjectManagerImpl.java:3751)
在org.datanucleus.ObjectManagerImpl。preCommit(ObjectManagerImpl.java:4141)
在org.datanucleus.ObjectManagerImpl.transaction preCommit(ObjectManagerImpl.java:428)
在org.datanucleus.TransactionImpl.internal preCommit(TransactionImpl.java:398)
在org.datanucleus.TransactionImpl.commit(TransactionImpl.java:287)
在org.datanucleus.ObjectManagerImpl.close(ObjectManagerImpl.java:1090)
在org.datanucleus.api.jpa.JPAEntityManager.close(JPAEntityManager.java:193)
在com.sandeepapplabs.dms.VehicleEndpoint.updateVehicle(VehicleEndpoint.java:130)
在sun.reflect.NativeMethodAccessorImpl.invoke0(本机方法)
在sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
在sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
在java.lang.reflect.Method.invoke(Method.java:45)
在com.google.api.server.spi.SystemService.invokeServiceMethod(SystemService.java:359)
在com.google.api.server.spi.SystemServiceServlet.execute(SystemServiceServlet.java:160)
在com.google.api.server.spi.SystemServiceServlet.doPost(SystemServiceServlet.java:118)
在javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
在javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
在org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
在org.mortbay.jetty.servlet.ServletHandler $ CachedChain.doFilter(ServletHandler.java:1166)
在org.mortbay.jetty.servlet.ServletHandler $ CachedChain.doFilter(ServletHandler.java:1157)
在org.mortbay.jetty.servlet.ServletHandler $ CachedChain.doFilter(ServletHandler.java:1157)
在org.mortbay.jetty.servlet.ServletHandler $ CachedChain.doFilter(ServletHandler.java:1157)
在org.mortbay.jetty.servlet.ServletHandler $ CachedChain.doFilter(ServletHandler.java:1157)
在org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
在org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
在org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
在org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
在org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
在org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
在org.mortbay.jetty.Server.handle(Server.java:326)
在org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
在org.mortbay.jetty.HttpConnection $ RequestHandler.headerComplete(HttpConnection.java:923)
在org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
在com.google.tracing.TraceContext $ TraceContextRunnable.runInContext(TraceContext.java:438)
在com.google.tracing.TraceContext $ TraceContextRunnable $ 1.运行(TraceContext.java:445)
在com.google.tracing.CurrentContext.runInContext(CurrentContext.java:220)
在com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:309)
在com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:301)
在com.google.tracing.TraceContext $ TraceContextRunnable.run(TraceContext.java:442)
在java.lang.Thread.run(Thread.java:724)
确定我能够通过改变ParentObject的主键来解决这个问题。
@Id
@GeneratedValue(策略= GenerationType.IDENTITY)
私人龙ID;
很多在类似这样的问题,研究帮助我这个
I'm new to android and gae and facing issue while updating a entity (An object containing a list of child objects) in GAE (backend for android) from android app
Scenario is:
I already have parent object saved in datasource. I then fetch this object and add list of child object (newly created) and then fire update. My entities are:
Parent Object
public class ParentObject {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Key key;
private String placeId;
@OneToOne(cascade = CascadeType.ALL)
private List<ChildObject> childObjects;
public Key getKey() {
return key;
}
public void setKey(Key key) {
this.key = key;
}
public String getPlaceId() {
return placeId;
}
public void setPlaceId(String placeId) {
this.placeId = placeId;
}
public List<ChildObject> getChildObject() {
return childObjects;
}
public void setChildObject(List<ChildObject> childObjects) {
this.childObjects = childObjects;
}
}
Child Object
@Entity
public class ChildObject {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Key key;
private String userEmail;
public Key getKey() {
return key;
}
public void setKey(Key key) {
this.key = key;
}
public String getUserEmail() {
return userEmail;
}
public void setUserEmail(String userEmail) {
this.userEmail = userEmail;
}
}
And update AsyncTask code is
@Override
protected ParentObject doInBackground(ParentObject... params) {
ParentObject parentObj = params[0];
Parentobjectendpoint.Builder builder = new Parentobjectendpoint.Builder(
AndroidHttp.newCompatibleTransport(), new JacksonFactory(),
null);
builder = CloudEndpointUtils.updateBuilder(builder);
Parentobjectendpoint endpoint = builder.build();
ParentObject updatedObj;
try {
updatedObj = endpoint.updateParentObject(parentObj).execute();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
updatedObj = null;
}
return updatedObj;
}
The error which I'm getting is
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.<init>(Batcher.java:180)
at com.google.appengine.api.datastore.Batcher$2.<init>(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)
at com.sandeepapplabs.dms.VehicleEndpoint.updateVehicle(VehicleEndpoint.java:130)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:45)
at com.google.api.server.spi.SystemService.invokeServiceMethod(SystemService.java:359)
at com.google.api.server.spi.SystemServiceServlet.execute(SystemServiceServlet.java:160)
at com.google.api.server.spi.SystemServiceServlet.doPost(SystemServiceServlet.java:118)
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 org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$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 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$RequestHandler.headerComplete(HttpConnection.java:923)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:438)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:445)
at com.google.tracing.CurrentContext.runInContext(CurrentContext.java:220)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:309)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:301)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:442)
at java.lang.Thread.run(Thread.java:724)
OK I was able to solve the issue by changing primary key of ParentObject to
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
A lot of research at questions similar to this helped me out with this
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