DDevelopment & Design

Unable to instantiate default tuplizer

I wrote few hbm mappings for domain classes in my recent project, and I got exception like that:org.hibernate.HibernateException: Unable to instantiate default tuplizer [org.hibernate.tuple.entity.PojoEntityTuplizer]Of course my first thought was googl…

I wrote few hbm mappings for domain classes in my recent project, and I got exception like that:

org.hibernate.HibernateException: Unable to instantiate default tuplizer [org.hibernate.tuple.entity.PojoEntityTuplizer]

Of course my first thought was googling for it and I found interesting answers. Most commons causes of this exception are:

  • missing getters or setters, what’s more, even a typo or wrong letter case (like getParentproject instead of getParentProject when field in class and mapping file is defined as parentProject)
  • missing default constructor
  • missing dependency for javassist library
My files seemed to be correctly defined, so it had to be missing dependency.

To fix it I’ve added these lines to my pom.xml:

<dependency>
    <groupId>org.javassist</groupId>
    <artifactId>javassist</artifactId>
    <version>3.18.0-GA</version>
</dependency>

Well, it shouldn’t be a surprise because in full stacktrafe from this error there is an entry:

java.lang.ClassNotFoundException: javassist.util.proxy.MethodFilter

What explicitly indicates where is the root of this problem ;)

(And BTW: in my recent project I’m stuck with quite old version of Hibernate – 3.6.3)

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… you can use it in your shell e.g. for json:
{
"store": {
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"bicycle": {
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You can print only book nodes with price lower than 10 by:
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Result:
[
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"category": "reference",
"price": 8.95,
"title": "Sayings of the Century",
"author": "Nigel Rees"
  },
  {
"category": "fiction",
"price": 8.99,
"title": "Moby Dick",
"isbn": "0-553-21311-3",
"author": "Herman Melville"
  }
]

Have a nice JSON hacking!From time to time I have a need to do some fixes in my json data. In a world of flat files I do this with grep/sed/awk tool chain. How to handle it for JSON? Searching for a solution I came across the JSONPath. It quite mature tool (from 2007) but I haven't hear about it so I decided to share my experience with others.
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