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  • EC2 persistence of machine

    - by Seagull
    I want to 'persist' my Amazon EC2 images. My scenario: I have a range of Windows and Linux machines Some machines are EBS backed, whereas others are S3 backed. I need to be able to persist a machine (put it to sleep), preferably keeping all settings active I had them when the machine was running. I need to be able to quickly wake up a machine from sleep [Ideally with an SLA of less than 2 min to turn-on, if such an SLA is available with Amazon]. Here's the stuff that confuses me: AWS allows me to put EBS backed machines to sleep, but not S3 backed. I believe I can put S3 machines into some sort of persistence mode. But this involves shutting down the machine, writing it to S3 storage and then recovering from there (not a real sleep mode, but at least I don't continue to get billed for CPU). S3 backing seems to take a long time to either writing a machine to disk, or to recover (turn on a machine). I can't tell immediately which machines are EBS backed and which are S3 backed? It seems like I can instantiate either type, but it's not immediately clear how Amazon decided whether a given machine should be EBS or S3 backed. Advice?

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  • Understanding Hibernate saveOrUpdate and the Persistence Life Cycle

    - by Stephano
    The books that I've read regarding hibernate are, at best, reference tomes. They very seldom have good code examples, so I tend to use online resources for those needs. However, I've always had a problem understanding the basic idea of hibernate persistence. I've read the books and understand the concepts, but in practice, I often see results that I don't understand. Perhaps you all can help, as you have in the past. Let's look at a simple example of a dog and a cat that are friends. This isn't a rare occurrence. It also has the benefit of being much more interesting than my business case. We want a function called "saveFriends" that takes a dog name and a cat name. We'll save the Dog and then the Cat. For this example to work, the cat is going to have a reference back to the dog. I understand this isn't an ideal example, but it's cute and works for our purposes. FriendService.java public int saveFriends(String dogName, String catName) { Dog fido = new Dog(); Cat felix = new Cat(); fido.name = dogName; fido = animalDao.saveDog(fido); felix.name = catName; [ex.A]felix.friend = fido; [ex.B]felix.friend = animalDao.getDogByName(dogName); animalDao.saveCat(felix); } AnimalDao.java (extends HibernateDaoSupport) public Dog saveDog(Dog dog) { getHibernateTemplate().saveOrUpdate(dog); return dog } public Cat saveCat(Cat cat) { getHibernateTemplate().saveOrUpdate(cat); return cat; } public Dog getDogByName(String name) { return (Dog) getHibernateTemplate().find("from Dog where name=?", name).get(0); } Now, assume for a minute that I would like to use either example A or example B to save my friend. Is one better than the other to use? I'll understand if neither of those examples work, but please explain why.

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  • JPA 2.1 Schema Generation (TOTD #187)

    - by arungupta
    This blog explained some of the key features of JPA 2.1 earlier. Since then Schema Generation has been added to JPA 2.1. This Tip Of The Day (TOTD) will provide more details about this new feature in JPA 2.1. Schema Generation refers to generation of database artifacts like tables, indexes, and constraints in a database schema. It may or may not involve generation of a proper database schema depending upon the credentials and authorization of the user. This helps in prototyping of your application where the required artifacts are generated either prior to application deployment or as part of EntityManagerFactory creation. This is also useful in environments that require provisioning database on demand, e.g. in a cloud. This feature will allow your JPA domain object model to be directly generated in a database. The generated schema may need to be tuned for actual production environment. This usecase is supported by allowing the schema generation to occur into DDL scripts which can then be further tuned by a DBA. The following set of properties in persistence.xml or specified during EntityManagerFactory creation controls the behaviour of schema generation. Property Name Purpose Values javax.persistence.schema-generation-action Controls action to be taken by persistence provider "none", "create", "drop-and-create", "drop" javax.persistence.schema-generation-target Controls whehter schema to be created in database, whether DDL scripts are to be created, or both "database", "scripts", "database-and-scripts" javax.persistence.ddl-create-script-target, javax.persistence.ddl-drop-script-target Controls target locations for writing of scripts. Writers are pre-configured for the persistence provider. Need to be specified only if scripts are to be generated. java.io.Writer (e.g. MyWriter.class) or URL strings javax.persistence.ddl-create-script-source, javax.persistence.ddl-drop-script-source Specifies locations from which DDL scripts are to be read. Readers are pre-configured for the persistence provider. java.io.Reader (e.g. MyReader.class) or URL strings javax.persistence.sql-load-script-source Specifies location of SQL bulk load script. java.io.Reader (e.g. MyReader.class) or URL string javax.persistence.schema-generation-connection JDBC connection to be used for schema generation javax.persistence.database-product-name, javax.persistence.database-major-version, javax.persistence.database-minor-version Needed if scripts are to be generated and no connection to target database. Values are those obtained from JDBC DatabaseMetaData. javax.persistence.create-database-schemas Whether Persistence Provider need to create schema in addition to creating database objects such as tables, sequences, constraints, etc. "true", "false" Section 11.2 in the JPA 2.1 specification defines the annotations used for schema generation process. For example, @Table, @Column, @CollectionTable, @JoinTable, @JoinColumn, are used to define the generated schema. Several layers of defaulting may be involved. For example, the table name is defaulted from entity name and entity name (which can be specified explicitly as well) is defaulted from the class name. However annotations may be used to override or customize the values. The following entity class: @Entity public class Employee {    @Id private int id;    private String name;     . . .     @ManyToOne     private Department dept; } is generated in the database with the following attributes: Maps to EMPLOYEE table in default schema "id" field is mapped to ID column as primary key "name" is mapped to NAME column with a default VARCHAR(255). The length of this field can be easily tuned using @Column. @ManyToOne is mapped to DEPT_ID foreign key column. Can be customized using JOIN_COLUMN. In addition to these properties, couple of new annotations are added to JPA 2.1: @Index - An index for the primary key is generated by default in a database. This new annotation will allow to define additional indexes, over a single or multiple columns, for a better performance. This is specified as part of @Table, @SecondaryTable, @CollectionTable, @JoinTable, and @TableGenerator. For example: @Table(indexes = {@Index(columnList="NAME"), @Index(columnList="DEPT_ID DESC")})@Entity public class Employee {    . . .} The generated table will have a default index on the primary key. In addition, two new indexes are defined on the NAME column (default ascending) and the foreign key that maps to the department in descending order. @ForeignKey - It is used to define foreign key constraint or to otherwise override or disable the persistence provider's default foreign key definition. Can be specified as part of JoinColumn(s), MapKeyJoinColumn(s), PrimaryKeyJoinColumn(s). For example: @Entity public class Employee {    @Id private int id;    private String name;    @ManyToOne    @JoinColumn(foreignKey=@ForeignKey(foreignKeyDefinition="FOREIGN KEY (MANAGER_ID) REFERENCES MANAGER"))    private Manager manager;     . . . } In this entity, the employee's manager is mapped by MANAGER_ID column in the MANAGER table. The value of foreignKeyDefinition would be a database specific string. A complete replay of Linda's talk at JavaOne 2012 can be seen here (click on CON4212_mp4_4212_001 in Media). These features will be available in GlassFish 4 promoted builds in the near future. JPA 2.1 will be delivered as part of Java EE 7. The different components in the Java EE 7 platform are tracked here. JPA 2.1 Expert Group has released Early Draft 2 of the specification. Section 9.4 and 11.2 provide all details about Schema Generation. The latest javadocs can be obtained from here. And the JPA EG would appreciate feedback.

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  • Why does JPA require a no-arg constructor for domain objects ?

    - by Jacques René Mesrine
    Why does JPA require a no-arg constructor for domain objects ? I am using eclipselink and just got this exception during deployment. Exception [EclipseLink-63] (Eclipse Persistence Services-1.1.0.r3639-SNAPSHOT): org.eclipse.persistence.exceptions.DescriptorException Exception Description: The instance creation method [com.me.model.UserVO.<Default Constructor>], with no parameters, does not exist, or is not accessible. Internal Exception: java.lang.NoSuchMethodException: com.me.model.UserVO.<init>() Descriptor: RelationalDescriptor(com.me.model.UserVO --> [DatabaseTable(user)])

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  • Persistance Queue Implementation

    - by Winter
    I was reading an article on Batch Processing in java over at JDJ http://java.sys-con.com/node/415321 . The article mentioned using a persistence queue as a Batch Updater instead of immediately sending an individual insert or update to the database. The author doesn't give a concrete example of this concept so I googled Persistence Queue but that didn't come up with much. Does anyone know of a good example of this?

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  • JAVA: how to load database url from web.xml?

    - by user357255
    I'm using persistence API and want to load jdbc URL from web.xml. URL should be a context parameter of servlet. I can't find how to construct EntityManagerFactory not using persistence.xml. May be I should create PersistenceUnit in servlet and set some parameters? Can you give me some short example? Thank you

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  • JPA - Performance with using multiple entity manager

    - by Nguyen Tuan Linh
    My situation is: The code is not mine I have two kinds of database: one is Dad, one is Son. In Dad, I have a table to store JNDI name. I will look up Dad using JNDI, create entity manager, and retrieve this table. From these retrieved JNDI names, I will create multiple entity managers using multiple Son databases. The problem is: Son have thousands of entities. It takes each Son database around 10 minutes to load all entities. If there is 4 Son databases, it will be 40 minutes. My question: Is there any way to load all entities and use them for all entity manager? Please look at the code below For each Son JNDI: Map<String, String> puSonProperties = new HashMap<String, String>(); puSonProperties.put("javax.persistence.jtaDataSource", sonJndi); EntityManagerFactory emf = Persistence.createEntityManagerFactory("PUSon", puSonProperties); PUSon - All of them use the same persistence unit log.info("Verify entity manager for son: {0} - {1}", sonCode, emSon.find(Son_configuration.class, 0) != null ? "ok" : "failed!"); This is the actual code where the loading of all entities begins. 10 mins.

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  • Having an issue with Onejar-Maven-Plugin

    - by reverendgreen
    I am trying to package a simple maven java project (uses javax.persistence api) into a single jar using the onejar-maven-plugin. I can run the program fine in eclipse; however when execute the onejar I get the exception below. If someone could provide some insight, that would be appreciated. Thanks, RG Exception in thread "main" java.lang.reflect.InvocationTargetException 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.simontuffs.onejar.Boot.run(Boot.java:306) at com.simontuffs.onejar.Boot.main(Boot.java:159) Caused by: Exception [EclipseLink-30005] (Eclipse Persistence Services - 2.0.0.v20091127-r5931): org.eclipse.persistence.exceptions.PersistenceUnitLoadingExcept Exception Description: An exception was thrown while searching for persistence archives with ClassLoader: com.simontuffs.onejar.JarClassLoader@190d11 Internal Exception: java.lang.ClassCastException: sun.misc.Launcher$AppClassLoader cannot be cast to com.simontuffs.onejar.JarClassLoader at org.eclipse.persistence.exceptions.PersistenceUnitLoadingException.exceptionSearchingForPersistenceResources(PersistenceUnitLoadingException.java:126 at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvider.java:133) at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvider.java:65) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:78) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54) at com.test.onejartest.App.main(App.java:19) ... 6 more Caused by: java.lang.ClassCastException: sun.misc.Launcher$AppClassLoader cannot be cast to com.simontuffs.onejar.JarClassLoader at com.simontuffs.onejar.JarClassLoader.getByteStream(JarClassLoader.java:753) at com.simontuffs.onejar.Handler$1.getInputStream(Handler.java:50) at java.net.URL.openStream(Unknown Source) at org.eclipse.persistence.internal.jpa.deployment.ArchiveFactoryImpl.isJarInputStream(ArchiveFactoryImpl.java:124) at org.eclipse.persistence.internal.jpa.deployment.ArchiveFactoryImpl.createArchive(ArchiveFactoryImpl.java:106) at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.findPersistenceArchives(PersistenceUnitProcessor.java:213) at org.eclipse.persistence.internal.jpa.deployment.JPAInitializer.findPersistenceUnitInfoInArchives(JPAInitializer.java:134) at org.eclipse.persistence.internal.jpa.deployment.JPAInitializer.findPersistenceUnitInfo(JPAInitializer.java:125) at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvider.java:98) ... 10 more pom.xml: ... <pluginRepositories> <pluginRepository> <id>onejar-maven-plugin.googlecode.com</id> <url>http://onejar-maven-plugin.googlecode.com/svn/mavenrepo</url> </pluginRepository> </pluginRepositories> ... <build> <plugins> <plugin> <groupId>org.dstovall</groupId> <artifactId>onejar-maven-plugin</artifactId> <version>1.3.0</version> <executions> <execution> <configuration> <mainClass>com.test.onejartest.App</mainClass> </configuration> <goals> <goal>one-jar</goal> </goals> </execution> </executions> </plugin> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>2.3.1</version> <configuration> <target>1.6</target> <source>1.6</source> </configuration> </plugin> </plugins> </build> ... <dependencies> <dependency> <groupId>javax.persistence</groupId> <artifactId>persistence-api</artifactId> <version>2.0.0</version> </dependency> <dependency> <groupId>org.eclipse.persistence</groupId> <artifactId>eclipselink</artifactId> <version>2.0.0</version> </dependency> <dependency> <groupId>com.microsoft.sqlserver.jdbc</groupId> <artifactId>sqljdbc</artifactId> <version>4.0.0</version> </dependency> </dependencies>

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  • JPA Entity (in multiple persistence-unit) in OSGi (Spring DM) Environnement is confusing me.

    - by Vincent Demeester
    Hi, I'm a bit confused about a strange behavior of my JPA's related objects. I have three bundle : The User bundle does contain some user-related objects, but mainly the User object. The Energy bundle does contain some energy-related objects, and particularly a ConsumptionTerminal which contains a List of User. The Index bundle does contain an Index object that has no dependency at all. My OSGi environment is the following : A DataSource bundle that provide 2 services : dataSource and jpaVendorAdapter. The three bundles. They consume dataSource and jpaVendorAdapter. Their module-context.xml file look like : And they all have a persistence.xml file : User <?xml version="1.0" encoding="UTF-8"?> <persistence> <persistence-unit name="securityPU" transaction-type="JTA"> <jta-data-source>java:/securityDataSourceService</jta-data-source> <class>net.nextep.amundsen.security.domain.User</class> <!-- [...] --> <exclude-unlisted-classes>true</exclude-unlisted-classes> <properties> <property name="eclipselink.logging.level" value="INFO" /> <property name="eclipselink.ddl-generation" value="create-tables" /> <property name="eclipselink.ddl-generation.output-mode" value="database" /> <property name="eclipselink.orm.throw.exceptions" value="true" /> </properties> </persistence-unit> </persistence> Energy <?xml version="1.0" encoding="UTF-8"?> <persistence> <persistence-unit name="energyPU" transaction-type="JTA"> <jta-data-source>java:/securityDataSourceService</jta-data-source> <class>net.nextep.amundsen.security.domain.User</class> <class>net.nextep.amundsen.energy.domain.User</class> <!-- [...] --> <exclude-unlisted-classes>true</exclude-unlisted-classes> <properties> <property name="eclipselink.logging.level" value="INFO" /> <property name="eclipselink.ddl-generation" value="create-tables" /> <property name="eclipselink.ddl-generation.output-mode" value="database" /> <property name="eclipselink.orm.throw.exceptions" value="true" /> </properties> </persistence-unit> </persistence> Index : This one has the most simple persistence.xml with just the Index class (no shared Class). I'm using named @PersistenceUnit annotation like @PersitenceUnit(name = 'securityPU') (for the User bundle). And finally, I'm using EclipseLink as Jpa provider and Spring DM (+ Spring DM Server in the development process) The problem is the following : When the User bundle is deployed, I'm able to persist User objects. When the User bundle and Energy bundles are both deployed, I'm not able to persist User objects (neither the Energy object). But I don't have any exception at all ! There is no problem at all with the Index bundle. The bug is dataSource independent (I tried with PostgreSQL and MySQL so far). My first conclusion was that the <class>net.nextep.amundsen.security.domain.User</class> in both persistence unit was causing the trouble. I tried without it (and hiding the User dependent object in the Energy bundle) but it failed too. I'm a bit confused about that bug. I'm also not quite sure about the transaction management in this context. I wasn't the one who designed this architecture (but I tell my intern OK without testing it.. shame on me) but if I could understand this bug and maybe fix it without rewrite the bundle (and break my intern work), I would appreciate. Am I doing something wrong ? (it's obvious, but what..) Did I miss something while reading documentation ? By the way, I'm also looking for some best practices or advices when it comes to JPA, EclipseLink (or whatever JPA Provider) and Spring DM (and OSGi in general). I found interesting slides from Mike Keith about this topic (by browsing Stackoverflow).

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  • Detach an entity from a JPA persistence context (JPA 2.0 / Hibernate / EJB 3 / J2EE 6)

    - by Julien
    Hi, I wrote a stateless EJB method allowing to get an entity in "read-only" mode. The way to do this is to get the entity with the EntityManager then detach it (using the JPA 2.0 EntityManager). My code is the following: @PersistenceContext private EntityManager entityManager; public T getEntity(int entityId, Class<T> specificClass, boolean readOnly) throws Exception{ try{ T entity = (T)entityManager.find(specificClass, entityId); if (readOnly){ entityManager.detach(entity); } return entity; }catch (Exception e){ logger.error("", e); throw e; } } Getting the entity works fine, but the call to the detach method returns the following error: GRAVE: javax.ejb.EJBException at ... Caused by: java.lang.AbstractMethodError: org.hibernate.ejb.EntityManagerImpl.detach(Ljava/lang/Object;)V at com.sun.enterprise.container.common.impl.EntityManagerWrapper.detach(EntityManagerWrapper.java:973) at com.mycomp.dal.MyEJB.getEntity(MyEJB.java:37) I can't get more information and don't understand what the problem is... Could somebody help ?

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  • sharp architecture, FluentNHibernate, automapper, DTO, 1:m persistence question

    - by csetzkorn
    Let us say we have a class A which has a reference to another class B (1:m) public class A { public virtual B B { get; set; } } I reflect this using FluentNHibernate within the sharp architecture and also manage to ‘initialise’ A and its B via a DTO and Automapper. The DTO contain A’s values and B (just B’s id value/A’s foreign key initialised). I was hoping that I can persist A by ‘just’ using its 'out of the box repository' without requiring B’s repository using: SaveOrUpdate(A); (A has been mapped using AutoMapper and contains B with its Id initialised) Was my assumption too naive? Can I achieve this somehow (without ever requiring B’s repository)? Or do I have to use A’s and B’s repository in, for example, the controller or some other service layer? Thanks. Best wishes, Christian

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  • Changes in gcc/persistence of optimization flags gcc/C

    - by gnometorule
    Just curious. Using gcc/gdb under Ubuntu 9.10. Reading a C book that also often gives the disassembly of the object file. When reading in January, my disassembly looks a lot like the book's; now, it's quite different - possibly more optimized (I notice some re-arrangements in the assembly code now that, at least in the files I checked, look optimized). I have used optimization options -O1 - -O3 for gcc between the first and second read, but not before the first. (1) Is the use of optimization options persistent, aka, if you use them once, you'll use them until switching them off? That would be weird (browsed man file and at least did not see anything to that sort). In the unlikely case that it is true, how do you switch them off? (2) Has gcc's assembly changed through any recent upgrade? (3) Does gcc sometimes produce (significantly) different assembly code although same compile options are chosen? Thanks much.

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  • PERSISTENCE LOB WITH JPA

    - by rfders
    Hi, Folks. I have this problem using JBOSS, EJB3 and MSSQL Express . i'm trying to persist an entity with an Blob attribute which was converted into a byte[], apparently it create the entity perfectly, no error was logged at jboss's console. but when i check into database the column is null. i already checked the Object to byte[] method and it is fine. i tried assigning Image and varbinary(Max) data type to this column. so i really don't know what it happening, why the column is not inserted into database. thanks a lot.

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  • Optimal storage of data structure for fast lookup and persistence

    - by Mikael Svenson
    Scenario I have the following methods: public void AddItemSecurity(int itemId, int[] userIds) public int[] GetValidItemIds(int userId) Initially I'm thinking storage on the form: itemId -> userId, userId, userId and userId -> itemId, itemId, itemId AddItemSecurity is based on how I get data from a third party API, GetValidItemIds is how I want to use it at runtime. There are potentially 2000 users and 10 million items. Item id's are on the form: 2007123456, 2010001234 (10 digits where first four represent the year). AddItemSecurity does not have to perform super fast, but GetValidIds needs to be subsecond. Also, if there is an update on an existing itemId I need to remove that itemId for users no longer in the list. I'm trying to think about how I should store this in an optimal fashion. Preferably on disk (with caching), but I want the code maintainable and clean. If the item id's had started at 0, I thought about creating a byte array the length of MaxItemId / 8 for each user, and set a true/false bit if the item was present or not. That would limit the array length to little over 1mb per user and give fast lookups as well as an easy way to update the list per user. By persisting this as Memory Mapped Files with the .Net 4 framework I think I would get decent caching as well (if the machine has enough RAM) without implementing caching logic myself. Parsing the id, stripping out the year, and store an array per year could be a solution. The ItemId - UserId[] list can be serialized directly to disk and read/write with a normal FileStream in order to persist the list and diff it when there are changes. Each time a new user is added all the lists have to updated as well, but this can be done nightly. Question Should I continue to try out this approach, or are there other paths which should be explored as well? I'm thinking SQL server will not perform fast enough, and it would give an overhead (at least if it's hosted on a different server), but my assumptions might be wrong. Any thought or insights on the matter is appreciated. And I want to try to solve it without adding too much hardware :) [Update 2010-03-31] I have now tested with SQL server 2008 under the following conditions. Table with two columns (userid,itemid) both are Int Clustered index on the two columns Added ~800.000 items for 180 users - Total of 144 million rows Allocated 4gb ram for SQL server Dual Core 2.66ghz laptop SSD disk Use a SqlDataReader to read all itemid's into a List Loop over all users If I run one thread it averages on 0.2 seconds. When I add a second thread it goes up to 0.4 seconds, which is still ok. From there on the results are decreasing. Adding a third thread brings alot of the queries up to 2 seonds. A forth thread, up to 4 seconds, a fifth spikes some of the queries up to 50 seconds. The CPU is roofing while this is going on, even on one thread. My test app takes some due to the speedy loop, and sql the rest. Which leads me to the conclusion that it won't scale very well. At least not on my tested hardware. Are there ways to optimize the database, say storing an array of int's per user instead of one record per item. But this makes it harder to remove items.

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  • Session persistence problem

    - by YsoL8
    Hello I'm having a problem with getting sessions to persist, and having no luck searching, I need to ask. I can access the contents of my session as expected when first set, but as soon as the page refreshes I lose everything and I don't see why. session_start() is set and I'm not unseting or destroying anything. I looked at PHP Info under sessions and everything looks ok (but my understanding of sessions is limited). I'm running MAMP on OS 10.5, and the last time I used sessions they worked.

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  • Unit of Work pattern and persistence

    - by Mosh
    Hello, I have been reading about Unit of Work pattern but I am confused about how the UoW actually persists data. When we commit the changes, UoW should iterate through the list of Added, Updated and Deleted objects and somehow find a class responsible to Add, Update, Delete objects of a certain type. I couldn't find an example showing this technique. Any advice on this would be greatly appreciated. Mosh

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  • JPA One To Many Relationship Persistence Bug

    - by Brian
    Hey folks, I've got a really weird problem with a bi-directional relationship in jpa (hibernate implementation). A User is based in one Region, and a Region can contain many Users. So...relationship is as follows: Region object: @OneToMany(mappedBy = "region", fetch = FetchType.LAZY, cascade = CascadeType.ALL) public Set<User> getUsers() { return users; } public void setUsers(Set<User> users) { this.users = users; } User object: @ManyToOne(cascade = {CascadeType.PERSIST, CascadeType.MERGE}, fetch = FetchType.EAGER) @JoinColumn(name = "region_fk") public Region getRegion() { return region; } public void setRegion(Region region) { this.region = region; } So, the relationship as you can see above is Lazy on the region side, ie, I don't want the region to eager load all the users. Therefore, I have the following code within my DAO layer to add a user to an existing user to an existing region object... public User setRegionForUser(String username, Long regionId){ Region r = (Region) this.get(Region.class, regionId); User u = (User) this.get(User.class, username); u.setRegion(r); Set<User> users = r.getUsers(); users.add(u); System.out.println("The number of users in the set is: "+users.size()); r.setUsers(users); this.update(r); return (User)this.update(u); } The problem is, when I run a little unit test to add 5 users to my region object, I see that the region.getUsers() set always stays stuck at 1 object...somehow the set isn't getting added to. My unit test code is as follows: public void setUp(){ System.out.println("calling setup method"); Region r = (Region)ManagerFactory.getCountryAndRegionManager().get(Region.class, Long.valueOf("2")); for(int i = 0; i<loop; i++){ User u = new User(); u.setUsername("username_"+i); ManagerFactory.getUserManager().update(u); ManagerFactory.getUserManager().setRegionForUser("username_"+i, Long.valueOf("2")); } } public void tearDown(){ System.out.println("calling teardown method"); for(int i = 0; i<loop; i++){ ManagerFactory.getUserManager().deleteUser("username_"+i); } } public void testGetUsersForRegion(){ Set<User> totalUsers = ManagerFactory.getCountryAndRegionManager().getUsersInRegion(Long.valueOf("2")); System.out.println("Expecting 5, got: "+totalUsers.size()); this.assertEquals(5, totalUsers.size()); } So the test keeps failing saying there is only 1 user instead of the expected 5. Any ideas what I'm doing wrong? thanks very much, Brian

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  • Domain model: should things like Logging, Audit, Persistence be in it

    - by hom.tanks
    I'm having a hard time convincing our architect that a Domain model should only have the essential elements of the business domain on it. Things like the fact that a class is persistable, that it needs logging and auditing and that it has a RESTful URI should not drive the domain model. They can be added later on, by using interfaces. Ours is a healthcare information management system. At the very coarse level, its a system where users login and access their healthcare information. They can share this information with others and be custodian for others' information (think Roles). But because of a few sound bytes that caught on early like "Everything should be a REST resource" the model now has a top level class called Resource that every other class extends from. I'm trying to make him see that the domain model should have well defined concepts like User Account, HealthDocument, UserRole etc which are distinct entities of the business , with specific associations between them. Clubbing everything under Resource class lets our model be inflexible besides being potentially incorrect. But he wants me to show him why its a bad idea to do it his way. I don't know how to articulate that properly but all my OO instincts tell me that its just not right. Any thoughts?

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  • Persistence of texture parameters

    - by fen
    I use glBindTexture() to bind a previously created texture. After the glBindTexture() call I use glTexParameteri() to set MIN and MAG filter. No problem so far. Are those parameters I set using glTexParameteri() bound to the texture itself or are they lost if I bind another texture. Do i have to set them again? glGenTexture(1, &tex1); glGenTexture(1, &tex2); /* bind tex1 and set params */ glBindtexture(GL_TEXTURE_RECTANGLE_ARB, tex1); glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, ...); glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR); /* do something */ /* bind tex2 and set params */ glBindtexture(GL_TEXTURE_RECTANGLE_ARB, tex2); glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, ...); glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR); /* do something */ /* bind tex1 again */ glBindtexture(GL_TEXTURE_RECTANGLE_ARB, tex1); /* do i have to set the parameters from above again or are they stored with tex1? */

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  • JPA and PostqreSQL: long string persistence

    - by emanemos
    Can anybody tell me how to persist long text using JPA (I use PostgreSQL)? Here's the way I defined a very long string in my class: @Lob private String body; However, this produces a field of type charactervarying(255) in the database. Furthermore, I've tried to use @Column annotation: @Column(columnDefinition="TEXT") private String body; But everything in vain. I would be gratefull for a helpfull comment on this problem.

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  • Raising events and object persistence in Django

    - by Mridang Agarwalla
    Hi, I have a tricky Django problem which didn't occur to me when I was developing it. My Django application allows a user to sign up and store his login credentials for a sites. The Django application basically allows the user to search this other site (by scraping content off it) and returns the result to the user. For each query, it does a couple of queries of the other site. This seemed to work fine but sometimes, the other site slaps me with a CAPTCHA. I've written the code to get the CAPTCHA image and I need to return this to the user so he can type it in but I don't know how. My search request (the query, the username and the password) in my Django application gets passed to a view which in turn calls the backend that does the scraping/search. When a CAPTCHA is detected, I'd like to raise a client side event or something on those lines and display the CAPTCHA to the user and wait for the user's input so that I can resume my search. I would somehow need to persist my backend object between calls. I've tried pickling it but it doesn't work because I get the Can't pickle 'lock' object error. I don't know to implement this though. Any help/ideas? Thanks a ton.

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  • Persistence store in blackberry

    - by arunabha
    i am trying to save a simple string value "1".If i go back from one screen to another,its saving,but when i exit the app,and start again,i dont see that value being saved.I am implementing persistable interface.Can anyone suggest me where i am getting wrong import net.rim.device.api.util.Persistable; import net.rim.device.api.system.PersistentObject; import net.rim.device.api.system.PersistentStore; public class Persist implements Persistable { public static PersistentObject abc; public static String b; static { abc = PersistentStore.getPersistentObject(0xb92c8fe20b256b82L); } public static void data(){ synchronized (abc) { abc.setContents(1+""); abc.commit(); } } public static String getCurrQuestionNumber() { synchronized (abc) { System.out.println("new title is"+b); b= (String)abc.getContents(); System.out.println("title is"+b); return b; } } }

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