Gemfire JavaDocs_test

public interface PdxSerializer

The PdxSerializer interface allows domain classes to be serialized and deserialized as PDXs without modification of the domain class. It only requires that the domain class have a public zero-arg constructor and that it provides read and write access to the PDX serialized fields.

GemFire allows a single PdxSerializer to be configured on a cache using setPdxSerializer or client setPdxSerializer. It can also be configured in cache.xml using the pdx-serializer element. The same PdxSerializer should be configured on each member of a distributed system that can serialize or deserialize PDX data.

The toData method is used for serialization; fromData is used for deserialization. The order in which fields are serialized and deserialized in these methods for the same class must match. For the same class toData and fromData must write the same fields each time they are called.

If you can modify your domain class then use PdxSerializable instead.

Simple example:

 public class User {
   public final String name;
   public final int userId;

   public User(String name, int userId) {
     this.name = name;
     this.userId = userId;
   }
 }


 public class MyPdxSerializer implements PdxSerializer {
   public boolean toData(Object o, PdxWriter out) {
     if (o instanceof User) {
       User u = (User) o;
       out.writeString("name", u.name);
       out.writeInt("userId", u.userId);
       return true;
     } else {
       return false;
     }
   }

   public Object fromData(Class<?> clazz, PdxReader in) {
     if (User.class.isAssignableFrom(clazz)) {
       return new User(in.readString("name"), in.readInt("userId"));
     } else {
       return null;
     }
   }
 }