[jira] [Commented] (OPENNLP-776) Model Objects should be Serializable
[ https://issues.apache.org/jira/browse/OPENNLP-776?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15412332#comment-15412332 ] Tristan Nixon commented on OPENNLP-776: --- This pattern is quite common in frameworks that manage object state for you. Classes are instantiated via a no-arg constructor, and then state is set via setters and/or some specialized de-serialization method. Many different serialization frameworks work this way, such as JAXB, Jackson, etc. Also ORM frameworks (hibernate, JPA), IOC frameworks (Spring, CDI), and many others. > Model Objects should be Serializable > > > Key: OPENNLP-776 > URL: https://issues.apache.org/jira/browse/OPENNLP-776 > Project: OpenNLP > Issue Type: Improvement >Affects Versions: tools-1.5.3 >Reporter: Tristan Nixon >Priority: Minor > Labels: features, patch > Fix For: 1.6.1 > > Attachments: externalizable.patch > > > Marking model objects (ParserModel, SentenceModel, etc.) as Serializable can > enable a number of features offered by other Java frameworks (my own use case > is described below). You've already got a good mechanism for > (de-)serialization, but it cannot be leveraged by other frameworks without > implementing the Serializable interface. I'm attaching a patch to BaseModel > that implements the methods in the java.io.Externalizable interface as > wrappers to the existing (de-)serialization methods. This simple change can > open up a number of useful opportunities for integrating OpenNLP with other > frameworks. > My use case is that I am incorporating OpenNLP into a Spark application. This > requires that components of the system be distributed between the driver and > worker nodes within the cluster. In order to do this, Spark uses Java > serialization API to transmit objects between nodes. This is far more > efficient than instantiating models on each node independently. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Commented] (OPENNLP-776) Model Objects should be Serializable
[ https://issues.apache.org/jira/browse/OPENNLP-776?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15412320#comment-15412320 ] Tristan Nixon commented on OPENNLP-776: --- There are some slight differences depending on whether you want to implement Serializable or Externalizable, but the basic pattern is the same. When the Java serialization system de-serializes an object, it first looks for a no-arg constructor to create an instance of that object, then it relies on setters or the methods private void readObject(java.io.ObjectInputStream in) (for Serializable) or public void readExternal( ObjectInput in ) (for Externalizable) to handle reconstituting the object's state from the stream. To put it another way, you can't call readExternal (or readObject) until you have an instance to call it on. Even if I'm to create sub-classes of model classes that are themselves externalizable, my sub-class must provide a no-arg constructor, which begs the question of what parent-class constructor will it call. > Model Objects should be Serializable > > > Key: OPENNLP-776 > URL: https://issues.apache.org/jira/browse/OPENNLP-776 > Project: OpenNLP > Issue Type: Improvement >Affects Versions: tools-1.5.3 >Reporter: Tristan Nixon >Priority: Minor > Labels: features, patch > Fix For: 1.6.1 > > Attachments: externalizable.patch > > > Marking model objects (ParserModel, SentenceModel, etc.) as Serializable can > enable a number of features offered by other Java frameworks (my own use case > is described below). You've already got a good mechanism for > (de-)serialization, but it cannot be leveraged by other frameworks without > implementing the Serializable interface. I'm attaching a patch to BaseModel > that implements the methods in the java.io.Externalizable interface as > wrappers to the existing (de-)serialization methods. This simple change can > open up a number of useful opportunities for integrating OpenNLP with other > frameworks. > My use case is that I am incorporating OpenNLP into a Spark application. This > requires that components of the system be distributed between the driver and > worker nodes within the cluster. In order to do this, Spark uses Java > serialization API to transmit objects between nodes. This is far more > efficient than instantiating models on each node independently. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
