File Manipulation libraries

I have a project which I need to manipulate files. things like: create new file by a defined structure(header,data,trail). and then I need to things like search/validate/create/read.

basically I want to map the files to objects and vise versa.(I am willing to map them to objects coz it will be much more c开发者_StackOverflowomfortable for me to manipulate the fields inside each file via object)

I wonder if any of you deal with such things before? and maybe could recommend me on libraries which could easy my work.

thanks, ray.

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You may want to look at serialization and de-serialization

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If you want custom mapping, you need custom coding. I would suggest you look at DataInputStream and DataOutputStream.

Using these you can control the header, records and footer in any binary format you want.

I suggest you generate your serialization (if you need to have the afstest possible speed) or use reflections to do the translation. Just using reflection is pretty fast and much simpler than generating code. ;)

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In the end I Found a ORM framework called Canyon which mapping Files to Objects. but still had difficulties. so I have implemented my own ORM file to objects and vise versa.

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If you have a defined file layout with different content you should consider to use a template engine like FreeMarker or Velocity to generate your files. You can define templates here which will be filled with your dynamic content which you have to provide. Definitly better than to use System.out (I mean hard code your template text).

A library which helps for basic file manipulation is Apache Commons IO.

If you realy want to map your files to objects than it would be a Serialization/Deserialization as Angelom mentions. Many libraries help you to do this but the file format is fixed:

JSON: Jackson, GSON
XML: JAXB

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If you want the file read by 3rd party as well, how about using some popular existing exchange format such as CSV or XML?

XML is fully supported in standard library. There's plenty of CSV libraries out there, including Apache Commons CSV.