Why does JPA require a no-arg constructor for domain objects ?

Posted by Jacques René Mesrine on Stack Overflow See other posts from Stack Overflow or by Jacques René Mesrine
Published on 2010-05-11T07:20:22Z Indexed on 2010/05/11 7:24 UTC
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jpa

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java

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persistence

Why does JPA require a no-arg constructor for domain objects ? I am using eclipselink and just got this exception during deployment.

Exception [EclipseLink-63] (Eclipse Persistence Services-1.1.0.r3639-SNAPSHOT): 
org.eclipse.persistence.exceptions.DescriptorException

Exception Description: The instance creation method   
[com.me.model.UserVO.<Default Constructor>], with no parameters, 
  does not exist, or is not accessible.
Internal Exception: java.lang.NoSuchMethodException: 
  com.me.model.UserVO.<init>()
Descriptor: RelationalDescriptor(com.me.model.UserVO --> 
  [DatabaseTable(user)])

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