Question

When I do a Http POST to a Datanucleus Rest resource in my local Appengine developement server, the server throws this error:

Caused by: java.lang.ClassNotFoundException: org.datanucleus.NucleusContext
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
    at com.google.appengine.tools.development.IsolatedAppClassLoader.loadClass(IsolatedAppClassLoader.java:176)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
    ... 37 more

From what it seems, using Datnuclues Rest API on appengine is not permitted by the platform?

EDIT:
Datanucleus in the pom:

<dependency>
    <groupId>com.google.appengine.orm</groupId>
    <artifactId>datanucleus-appengine</artifactId>
    <version>2.0.0</version>
</dependency>
<dependency>
    <groupId>org.datanucleus</groupId>
    <artifactId>datanucleus-core</artifactId>
    <version>3.0.0-release</version>
</dependency>

<dependency>
    <groupId>org.datanucleus</groupId>
    <artifactId>datanucleus-api-jpa</artifactId>
    <version>3.0.0-release</version>
</dependency>
<dependency>
    <groupId>org.apache.geronimo.specs</groupId>
    <artifactId>geronimo-jpa_2.0_spec</artifactId>
    <version>1.0</version>
</dependency>

        <!-- Required by Datanucleus REST API -->
        <dependency>
            <groupId>org.datanucleus</groupId>
            <artifactId>datanucleus-rest</artifactId>
            <version>2.0.0-release</version>
        </dependency>
        <dependency>
            <groupId>net.sf.flexjson</groupId>
            <artifactId>flexjson</artifactId>
            <version>2.1</version>
        </dependency>
        <dependency>
            <groupId>org.datanucleus</groupId>
            <artifactId>datanucleus-json</artifactId>
            <version>2.0.0-release</version>
        </dependency>

Here are the DN-related jars in the WEB-INF/lib folder:

• datanucleus-rest-2.0.0-release.jar
• datanucleus-json-2.0.0-release.jar
• datanucleus-core-3.0.0-release.jar
• datanucleus-appengine-2.0.0.jar
• datanucleus-api-jpa-3.0.0-release.jar

EDIT:

Fixed the initial problem by using v3.0 DN dependencies.

However, now when I try to access the REST resource from the DN servlet it throws this error:

Error : An error occurred trying to instantiate an instance of the API adapter "org.datanucleus.api.jdo.JDOAdapter" (perhaps you dont have the requisite datanucleus-api-XXX jar in the CLASSPATH?) : {1}
org.datanucleus.exceptions.NucleusUserException: Error : An error occurred trying to instantiate an instance of the API adapter "org.datanucleus.api.jdo.JDOAdapter" (perhaps you dont have the requisite datanucleus-api-XXX jar in the CLASSPATH?) : {1}

Answer 1

So you use some version of datanucleus-api-rest (presumably 3.x) and you don’t have the requisite version of datanucleus-core (also 3.x) present. That is normally what a ClassNotFoundException means