JSON files

As for XML, Jolie natively supports automatic conversions also between Jolie and JSON data structures. This is leveraged by the File library service to give simple ways to read from and write to JSON files.

Reading from a JSON file

Say that you have a JSON file called note.json with the following content.

{
"note": {
"from": "John",
"to": "Jane",
"content": "I made pasta"
}
}

You can read from this file and obtain a Jolie data structure as follows.

include "file.iol"
main
{
filename = "note.json"
format = "json"
} )( data )
// data is now { node << { from = "John" to = "Jane" content = "I made pasta" } }
}

Variable data now contains the data from the JSON structure, which you can access as usual using the standard Jolie syntax. For example, to print the to node of the note, you can include "console.iol" at the beginning of the program and write:

[email protected]( data.note.to )() // "Jane"

Writing to a JSON file

Suppose that you wanted to store the following data structure as a JSON file.

{
note << {
from = "John"
to = "Jane"
content = "I made pasta"
}
}

You can do so by invoking [email protected] and passing that data structure as the content to be written.

include "file.iol"
main
{
filename = "note.json"
format = "json"
content << {
note << {
from = "John"
to = "Jane"
content = "I made pasta"
}
}
} )()
}

The file note.json will now contain the JSON data that we showed at the beginning of the tutorial.