Auto-Serialization Of Objects

This is a simple example that demonstrates auto-serialization of objects of classes that do not use Java serialization, PDX serialization, or data serialization. Reflection-based auto-serialization uses Java reflection to put objects into and get objects out of regions without relying on Java, PDX, or data serialization.

For an object to be stored in a region as either key or value, a copy of the object must be sent to the server. Typically Java objects are sent across the network by serializing them into bytes sent across a socket and then deserializing them from the bytes received from the socket on the other side. This requires those objects’ classes to implement a particular interface that defines how that serialization and deserialization is accomplished, e.g., java.io.Serializable, org.apache.geode.DataSerializable, or org.apache.geode.pdx.PdxSerializable.

In order to perform queries on objects within the server, the fields of the objects must be individually accessible. One way to accomplish this is to deserialize the objects into instances within the server. This requires the relevant classes to be in the server’s class path. Another way to accomplish this is by using the field-addressable format, PDX.

The reflection-based auto-serializer uses Java’s reflection and introspection to construct a PDX instance. This obviates modifying classes to implement a serialization interface. This also allows the objects to be queried by way of PDX without the classes being preset on the server’s class path.

This example assumes you have installed JDK11 and GemFire.

Steps

1. From the gemfire-examples/serialization directory, build the example and run unit tests

    $ ../gradlew build
   

2. Next start the locator and two servers

    $ gfsh run --file=scripts/start.gfsh
   

3. Run the example to create entries in the region

    $ ../gradlew run
   

4. Shut down the system:

    $ gfsh run --file=scripts/stop.gfsh