makani | scale airborne wind turbine , culminating in a flight test

Basically, use $project as a final stage and select ALL the specific fields you want. Unfortunately $addFields is out because it will actually "merge" the sub-keys with the existing ones. So the seemingly simple:

i changed servicelocationId as string in servicelocation collection now it's working fine.

"serviceLocationId" : ObjectId("598592dc8db31d6625a41290") to "serviceLocationId" : "598592dc8db31d6625a41290"

query:

Here's a recursive solution:

InputStreams can be used for binary formats, binary formats don't care about filtering new line characters.

You will either need to filter them yourself, or use a buffered reader/scanner and read line, then iterate along the characters in the string.

https://docs.oracle.com/javase/7/docs/api/java/io/InputStream.html#read()

Shows that it indeed does only read one character at a time, however the eclipse terminal may not be forwarding the data entered until you press enter.

When that happens your loop is running twice.

Scanner docs: https://docs.oracle.com/javase/8/docs/api/java/util/Scanner.html#nextLine--