MongoDB - How to consume printjson output in Java

I need to communicate with MongoDB shell via Java

To explain in short, I am using something like Runtime.exec (commons exec specifically) to call MongoDB shell in --eval mode

Using this approach, I am able to successfully invoke MongoDB commands, retrieve the output into a stream (and print to stdout for example)

All is well till this point.

I need to now "parse" this output into something like an array of JSONObject

(I can make use of any JSON library like Jackson, etc. that may be appropriate for this) so that I can "massage" the output based on some requirements. (Change the format, remove some key value pairs, etc.)

When I look at the output generated by printjson in c开发者_C百科ase of arrays at least, it does not seem to be a valid json array but rather valid json objects separated by new line without the comma in between or enclosing [] that would make it a valid array.

In this case, any suggestions on how to parse this output into some kind of holder objects that I can use to read/modify key value pairs?

I don't have the json commands at compile time but do know that these commands will always end in a printjson

EDIT -

So to simplify, for example, I am looking for a way to parse the following output into Java Objects -

(The individual key/value pairs are not known at compile time)

{
    "_id" : ObjectId("4db0e0289523f82ff6cd90d4"),
    "calendar_date" : "2009-11-10",
    "product_id" : 8,
    "channel" : "website",
    "country" : "USA",
    "total_unit_count" : 740,
    "total_amount" : 11367.29
}
{
    "_id" : ObjectId("4db0e0289523f82ff6cd90d5"),
    "calendar_date" : "2009-11-10",
    "product_id" : 8,
    "channel" : "website",
    "country" : "Australia",
    "total_unit_count" : 740,
    "total_amount" : 13893.09
}
{
    "_id" : ObjectId("4db0e0289523f82ff6cd90d6"),
    "calendar_date" : "2009-11-10",
    "product_id" : 8,
    "channel" : "retail",
    "country" : "USA",
    "total_unit_count" : 13,
    "total_amount" : 8296.89
}

You can run anything you can write in javascript in java directly (using the mongodb java driver).

It is a bad idea to shell out and try to consume the output from java. Instead you should run the commands/queries directly from the java using the driver.

it seems that com.mongodb.util.JSON does not extend DBObject, I'm not sure why people claim you can do collection.insert(JSON.parse(some json)). is there another way to insert the json that i'm missing?

edit: the answer is easy here, but isn't in the documentation. simply add a cast:

collection.insert((DBObject)JSON.parse(some json ... ));

What I was looking for does not seem possible at the moment.

What I ended up doing was to shell out the mongo calls, obtain the result stream in java, JSONize the result (get rid of object_id since i dont need it, convert dates appropriately, etc.) and then generate a json object from this modified result string. Ugly hack but the only one that seemed possible and it works.

If you ever find yourself in a similar boat and have specific questions, post in the comment below and I will help if I can.