Home
Prodotti
Red Hat Data Grid
6.4
Developer Guide
6.3. Using an Advanced Externalizer

Questo contenuto non è disponibile nella lingua selezionata.

6.3. Using an Advanced Externalizer

Using a customized advanced externalizer helps optimize performance in Red Hat JBoss Data Grid.

Define and implement the readObject() and writeObject() methods.
Link externalizers with marshaller classes.
Register the advanced externalizer.

6.3.1. Implement the Methods
Copia collegamento

To use advanced externalizers, define and implement the readObject() and writeObject() methods. The following is a sample definition:

Example 6.2. Define and Implement the Methods

import org.infinispan.commons.marshall.AdvancedExternalizer;
 
public class Person {
 
   final String name;
   final int age;
 
   public Person(String name, int age) {
      this.name = name;
      this.age = age;
   }
 
   public static class PersonExternalizer implements AdvancedExternalizer<Person> {
      @Override
      public void writeObject(ObjectOutput output, Person person)
            throws IOException {
         output.writeObject(person.name);
         output.writeInt(person.age);
      }
 
      @Override
      public Person readObject(ObjectInput input)
            throws IOException, ClassNotFoundException {
         return new Person((String) input.readObject(), input.readInt());
      }
 
      @Override
      public Set<Class<? extends Person>> getTypeClasses() {
         return Util.<Class<? extends Person>>asSet(Person.class);
      }
 
      @Override
      public Integer getId() {
         return 2345;
      }
   }
}

import org.infinispan.commons.marshall.AdvancedExternalizer;
 
public class Person {
 
   final String name;
   final int age;
 
   public Person(String name, int age) {
      this.name = name;
      this.age = age;
   }
 
   public static class PersonExternalizer implements AdvancedExternalizer<Person> {
      @Override
      public void writeObject(ObjectOutput output, Person person)
            throws IOException {
         output.writeObject(person.name);
         output.writeInt(person.age);
      }
 
      @Override
      public Person readObject(ObjectInput input)
            throws IOException, ClassNotFoundException {
         return new Person((String) input.readObject(), input.readInt());
      }
 
      @Override
      public Set<Class<? extends Person>> getTypeClasses() {
         return Util.<Class<? extends Person>>asSet(Person.class);
      }
 
      @Override
      public Integer getId() {
         return 2345;
      }
   }
}

Copy to Clipboard

Toggle word wrap

Note

This method does not require annotated user classes. As a result, this method is valid for classes where the source code is not available or cannot be modified.

Report a bug

6.3.2. Link Externalizers with Marshaller Classes
Copia collegamento

Use an implementation of getTypeClasses() to discover the classes that this externalizer can marshall and to link the readObject() and writeObject() classes.

The following is a sample implementation:

import org.infinispan.util.Util;
<!-- Additional configuration information here -->
@Override
public Set<Class<? extends ReplicableCommand>> getTypeClasses() {
  return Util.asSet(LockControlCommand.class, GetKeyValueCommand.class,
      ClusteredGetCommand.class, MultipleRpcCommand.class,
      SingleRpcCommand.class, CommitCommand.class,
      PrepareCommand.class, RollbackCommand.class,
      ClearCommand.class, EvictCommand.class,
      InvalidateCommand.class, InvalidateL1Command.class,
      PutKeyValueCommand.class, PutMapCommand.class,
      RemoveCommand.class, ReplaceCommand.class);
}

import org.infinispan.util.Util;
<!-- Additional configuration information here -->
@Override
public Set<Class<? extends ReplicableCommand>> getTypeClasses() {
  return Util.asSet(LockControlCommand.class, GetKeyValueCommand.class,
      ClusteredGetCommand.class, MultipleRpcCommand.class,
      SingleRpcCommand.class, CommitCommand.class,
      PrepareCommand.class, RollbackCommand.class,
      ClearCommand.class, EvictCommand.class,
      InvalidateCommand.class, InvalidateL1Command.class,
      PutKeyValueCommand.class, PutMapCommand.class,
      RemoveCommand.class, ReplaceCommand.class);
}

Copy to Clipboard

Toggle word wrap

In the provided sample, the ReplicableCommandExternalizer indicates that it can externalize several command types. This sample marshalls all commands that extend the ReplicableCommand interface but the framework only supports class equality comparison so it is not possible to indicate that the classes marshalled are all children of a particular class or interface.

In some cases, the class to be externalized is private and therefore the class instance is not accessible. In such a situation, look up the class with the provided fully qualified class name and pass it back. An example of this is as follows:

@Override
public Set<Class<? extends List>> getTypeClasses() {
 return Util.<Class<? extends List>>asSet(
       Util.<List>loadClass("java.util.Collections$SingletonList", null));
}

@Override
public Set<Class<? extends List>> getTypeClasses() {
 return Util.<Class<? extends List>>asSet(
       Util.<List>loadClass("java.util.Collections$SingletonList", null));
}

Copy to Clipboard

Toggle word wrap

Report a bug

6.3.3. Register the Advanced Externalizer (Declaratively)
Copia collegamento

After the advanced externalizer is set up, register it for use with Red Hat JBoss Data Grid. This registration is done declaratively (via XML) as follows:

Procedure 6.1. Register the Advanced Externalizer

<infinispan>
    <global>
        <serialization>
            <advancedExternalizers>            
                <advancedExternalizer externalizerClass="org.infinispan.marshall.AdvancedExternalizerTest$IdViaAnnotationObj$Externalizer"/>
            </advancedExternalizers>
        </serialization>
    </global>
</infinispan>

<infinispan>
    <global>
        <serialization>
            <advancedExternalizers>            
                <advancedExternalizer externalizerClass="org.infinispan.marshall.AdvancedExternalizerTest$IdViaAnnotationObj$Externalizer"/>
            </advancedExternalizers>
        </serialization>
    </global>
</infinispan>

Copy to Clipboard

Toggle word wrap

Add the global element to the infinispan element.
Add the serialization element to the global element.
Add the advancedExternalizers element to add information about the new advanced externalizer.
Define the externalizer class using the externalizerClass attributes. Replace the $IdViaAnnotationObj and $AdvancedExternalizer values as required.

Report a bug

6.3.4. Register the Advanced Externalizer (Programmatically)
Copia collegamento

After the advanced externalizer is set up, register it for use with Red Hat JBoss Data Grid. This registration is done programmatically as follows:

Example 6.3. Registering the Advanced Externalizer Programmatically

GlobalConfigurationBuilder builder = ...
builder.serialization()
   .addAdvancedExternalizer(new Person.PersonExternalizer());

GlobalConfigurationBuilder builder = ...
builder.serialization()
   .addAdvancedExternalizer(new Person.PersonExternalizer());

Copy to Clipboard

Toggle word wrap

Enter the desired information for the GlobalConfigurationBuilder in the first line.

Report a bug

6.3.5. Register Multiple Externalizers
Copia collegamento

Alternatively, register multiple advanced externalizers because GlobalConfiguration.addExternalizer() accepts varargs. Before registering the new externalizers, ensure that their IDs are already defined using the @Marshalls annotation.

Example 6.4. Registering Multiple Externalizers

builder.serialization()
   .addAdvancedExternalizer(new Person.PersonExternalizer(),
                            new Address.AddressExternalizer());

builder.serialization()
   .addAdvancedExternalizer(new Person.PersonExternalizer(),
                            new Address.AddressExternalizer());

Copy to Clipboard

Toggle word wrap

Report a bug

Torna in cima

Questo contenuto non è disponibile nella lingua selezionata.

6.3. Using an Advanced Externalizer

6.3.1. Implement the Methods
Copia collegamento

6.3.2. Link Externalizers with Marshaller Classes
Copia collegamento

6.3.3. Register the Advanced Externalizer (Declaratively)
Copia collegamento

6.3.4. Register the Advanced Externalizer (Programmatically)
Copia collegamento

6.3.5. Register Multiple Externalizers
Copia collegamento

Formazione

Prova, acquista e vendi

Community

Informazioni sulla documentazione di Red Hat

Rendiamo l’open source più inclusivo

Informazioni su Red Hat

Theme

Red Hat legal and privacy links

Red Hat legal and privacy links

Questo contenuto non è disponibile nella lingua selezionata.

6.3. Using an Advanced Externalizer

6.3.1. Implement the MethodsCopia collegamentoCollegamento copiato negli appunti!

6.3.2. Link Externalizers with Marshaller ClassesCopia collegamentoCollegamento copiato negli appunti!

6.3.3. Register the Advanced Externalizer (Declaratively)Copia collegamentoCollegamento copiato negli appunti!

6.3.4. Register the Advanced Externalizer (Programmatically)Copia collegamentoCollegamento copiato negli appunti!

6.3.5. Register Multiple ExternalizersCopia collegamentoCollegamento copiato negli appunti!

Formazione

Prova, acquista e vendi

Community

Informazioni sulla documentazione di Red Hat

Rendiamo l’open source più inclusivo

Informazioni su Red Hat

Theme

Red Hat legal and privacy links

Red Hat legal and privacy links

6.3.1. Implement the Methods
Copia collegamento

6.3.2. Link Externalizers with Marshaller Classes
Copia collegamento

6.3.3. Register the Advanced Externalizer (Declaratively)
Copia collegamento

6.3.4. Register the Advanced Externalizer (Programmatically)
Copia collegamento

6.3.5. Register Multiple Externalizers
Copia collegamento