Experimenting with JPA 2.0 and Spring 3.0.x. A libraries nightmare.

I was making JPA samples while I was reading Spring Persistence with Hibernate. I started to make everything from scratch. The book uses Maven to manage the sample project, but I'm not a Maven person, so I decided to leave Maven and do it the good old way : compile, see a ClassDefNotFoundException raised, find out which library I have to add to the classpath, download it, extract it, sometimes figure out which extracted libraries are not necessary, adding the necessary ones to my project... It sounds like Daft Punk's Technologic ! (compile it, break it, find it, get it, extract it, guess it, add it...) I finally made it, but I can't remember how long it took me to do all these steps. Too long for sure.

Which is why I started studying Maven ! Although I knew about Maven's dependencies management, I never actually used it. There are some good online books at Sonatype. I went straight to the Maven by Example book. This is a good book. I discovered that Maven is much more than a dependencies management tool !

From there, I made a new JPA/Spring project from scratch, using Eclipse's Maven plugin, and while looking at Spring Persistence with Hibernate's xml, I added the necessary dependencies. No effort. Maven did it all.

Here is my pom.xml, using Hibernate JPA, Spring 3.0.5(using transactions without aspectj) and H2Database. It looks big, but it's just a bunch of dependencies declarations, which are made even easier via Eclipse's plugin.

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>springwithmaven</groupId>
  <artifactId>springwithmaven</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>springwithmaven</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

    <repositories>
        <repository>
            <id>JBoss Repo</id>
            <url>http://repository.jboss.com/maven2</url>
            <name>JBoss Repo</name>
        </repository>
        <repository>
            <id>ibiblio mirror</id>
            <url>http://mirrors.ibiblio.org/pub/mirrors/maven2/</url>
        </repository>
        <repository>
            <id>jboss-public-repository-group</id>
            <name>JBoss Public Maven Repository Group</name>
            <url>https://repository.jboss.org/nexus/content/groups/public/</url>
            <layout>default</layout>
            <releases>
                <enabled>true</enabled>
                <updatePolicy>never</updatePolicy>
            </releases>
            <snapshots>
                <enabled>true</enabled>
                <updatePolicy>never</updatePolicy>
            </snapshots>
        </repository>
    </repositories>

  <dependencies>
 <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-core</artifactId>
     <version>3.0.5.RELEASE</version>
 </dependency>  
 <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-context</artifactId>
     <version>3.0.5.RELEASE</version>
 </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-entitymanager</artifactId>
      <version>3.4.0.GA</version>
    </dependency>
    
    <dependency>
     <groupId>org.hibernate.javax.persistence</groupId>
     <artifactId>hibernate-jpa-2.0-api</artifactId>
     <version>1.0.0.Final</version>
    </dependency>
    <dependency>
     <groupId>com.h2database</groupId>
     <artifactId>h2</artifactId>
     <version>1.3.149</version>
    </dependency>
    <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-tx</artifactId>
     <version>3.0.5.RELEASE</version>
     <type>jar</type>
     <scope>compile</scope>
    </dependency>
    <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-orm</artifactId>
     <version>3.0.5.RELEASE</version>
     <type>jar</type>
     <scope>compile</scope>
    </dependency>
    <dependency>
     <groupId>commons-dbcp</groupId>
     <artifactId>commons-dbcp</artifactId>
     <version>1.3</version>
     <type>jar</type>
     <scope>compile</scope>
    </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.6.0</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jcl-over-slf4j</artifactId>
            <version>1.6.0</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.6.0</version>
        </dependency>
        <dependency>
            <groupId>net.sf.ehcache</groupId>
            <artifactId>ehcache</artifactId>
            <version>1.6.2</version>
        </dependency>    
  </dependencies>
</project>

JPA 2.0 with Spring 3.0 bug

I was trying to make a sample application using Spring3 and JPA2 on my new shiny IntelliJ IDEA 10, but stumbled quickly on a problem when I tried to run the application. Spring was complaining that the version attribute in my persistence.xml was wrong. It was set to "2.0", but Spring insisted that it could only be "1.0". I spent hours trying to figure out where the problem was. A wrong XMLSchema being picked up ? A problem with my JPA libraries ? A problem with my JPA provider ? No. The problem was coming from Spring itself (SPR-6711). Upgrading to Spring 3.0.5 fixed it. What a waste of time. It wouldn't have happened if I had used the latest libraries in the first place, instead of letting IDEA automatically import them (I guess version 3.0.0 were downloaded and added to my project).