jdo

问题 Probably a very trivial problem. I have an object that looks like this: @PersistenceCapable public class Parent { @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) private String _id; @Persistent private List<Child> _children; //... } ... the nested entity looks like this (I am forced to declare primary key as Key otherwise it won't persist): @PersistenceCapable public class Child { @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) private Key _id;

问题 I have a problem with the GoogleAuthorizationCodeFlow ( Java ). I am trying to build a Google Calender connection for my web project using Google's "OAuth 2.0 for Web Server Applications". Therefore you are able to use Google's Java api libraries. I use Google's AuthorizationCallbackServlet to recieve an access and refresh token. GoogleAuthorizationCodeFlow persists the created Credential with GoogleAuthorizationCodeFlow and their JdoCredentialStore. As a JDO implementation I am using

问题 For an iOS project I'm using GAE (Java stack) to store the user's device token and use it to send Push notifications. I have a Device entity which contains several fields, including "appVersion" field of type String. The database contains some Devices with version 1 and some with version 2. When I run a JDO query to find all devices with "appVersion" equals to 2 it returns the expected result, but when I do the same with version 1 the query return no result, although there are Entities which

问题 I have used javax.jdo.Query like here JDO for Google App Engine: escaping quotes. Yet, my query string with single quote (') keep getting exploded. Query query = pm.newQuery("select from " + Book.class.getName() + " where mArtist== '"+ artist + "' && mTitle=='" + title + "'"); Here is the exception javax.jdo.JDOUserException: Portion of expression could not be parsed: 't Give Up' org.datanucleus.store.query.QueryCompilerSyntaxException: Portion of expression could not be parsed: 't Give Up'

问题 I would like to change the entity property from String to long. I have seen Nick answering similar problem in Change IntegerProperty to FloatProperty of existing AppEngine DataStore but I am writing in Java and need some code example since I don't know anything about the mapreduce. e.g. we want to change userId from String to Long of this class. I also would like to get advice on my thinking of storing date in long instead of String so that the time information can be consumed readily from

问题 I am using datanucleus and jdo in a GWT project. How can I retrieve the generated primary key after adding an element to the database with makePersistent() Edit We use annotations, here is the primary key: @PrimaryKey @Column(name = "id_bla", allowsNull = "false") @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY, extensions = { @Extension(vendorName = "datanucleus", key = "strategy-when-notnull", value = "false") }) private Long idBla; I am not the one who did the mapping and I don't

问题 I use mongodb-datanucleus in my project. I configure my jdoconfig.xml as follow : <persistence-manager-factory name="mongodb-factory"> <property name="javax.jdo.PersistenceManagerFactoryClass" value="org.datanucleus.api.jdo.JDOPersistenceManagerFactory" /> <property name="javax.jdo.option.ConnectionURL" value="mongodb:localhost/test" /> <property name="javax.jdo.option.Mapping" value="mongodb" /> <property name="javax.jdo.option.ConnectionUserName" value="username" /> <property name="javax

问题 I am using DataNucleus 3.0.0-release JDO implementation to connect my Java app to MongoDB. The related JARs in my CLASSPATH are as follows: datanucleus-api-jdo-3.0.0-release.jar datanucleus-core-3.0.0-release.jar datanucleus-jdo-query-3.0.0-release.jar datanucleus-mongodb-3.0.0-release.jar mongo-java-driver-2.5.2.jar UPDATE : This problem also occurred with version 3.1 and is related to DataNucleus' Level2 cache. See my answer below for a workaround. The class that I am trying to load is as

问题 I'm having this error in my AppEngine project: javax.persistence.PersistenceException: No persistence providers available for "transactions-optional" after trying the following discovered implementations: org.datanucleus.api.jpa.PersistenceProviderImpl at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:180) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:70) jdoconfig.xml <jdoconfig xmlns="http://java.sun.com/xml/ns/jdo/jdoconfig" xmlns

问题 I intend questions not to be a child since I had to manipulate it independently, and I don't want to persist the questions field, I would to fill it up by retrieving the questions manually. Here is the code. Questionnaire.java @PersistenceCapable(identityType = IdentityType.APPLICATION) public class Questionnaire{ //supposedly non-persistent public List<Question> questions = new ArrayList<Question>(); @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) public Long