JSON Blob

JSON Blob is a helper class to build a JSON String using a simple interface.

val jsonBlob = JsonBlob.obj(
  kv("name", "value"),
  kv("isOpen", true),
  kv("primes", array(2,3,5,7,11)),
  kv("address", obj(
    kv("streetAddress", "1 Apple Park Way",
    kv("city", "Cupertino"))
  )),
  kv("keys", array(
    obj(
      kv("key1", "value")
    )
  )),
  kv("empty", unit()),
  kv("masked", mask("secret", "***"))
)

val json = jsonBlob.toJson()
val maskedJson = jsonBlob.toJson(true)

Produces:

{"name":"value","isOpen":true,"primes":[2,3,5,7,11],"address":{"streetAddress":"1 Apple Park Way","city":"Cupertino"},"keys":[{"key1":"value"}],"empty":null,"masked":"secret"}

{"name":"value","isOpen":true,"primes":[2,3,5,7,11],"address":{"streetAddress":"1 Apple Park Way","city":"Cupertino"},"keys":[{"key1":"value"}],"empty":null,"masked":"***"}

Installation

JSON Blob is available from JCenter as well as Github Packages

repositories {
  jcenter()
}

dependencies {
  implementation("tech.basepair:json-blob:0.1.0")
}

JSON Blob API

The JSON Blob API consists of several methods:

• obj(varargs JsonKeyValue): JsonObject
• kv(String, JsonValue): JsonKeyValue
• array(varargs JsonValue): JsonArray
• v(Boolean | Number | String): JsonValue

In Java there are named methods for arrays:

• numArray
• boolArray
• strArray

Supplier APIs

For each of the methods above there is a supplier version which can be passed to optionally return a value.

val jsonBlob = obj(kv { if (someValue) { kv("b", 1) } else { null } })
...
obj(kv("a", v { if (someValue) { v("hello") } else { null } })

Printer

By default the obj() returned from JsonBlob exposes a toJson(mask: Boolean) and toJson(printer: Printer) methods that return the String representation of the JSON and underlying use a default Printer that utilises a StringBuilder. A custom printer can be passed in.

Masked JSON

The masked JSON replaces any content with the masked value supplied and the mask() method can take any of the JsonBlob types.

For example

val jsonBlob = kv("password", mask(v("goodbye"), "******")
json = jsonBlob.toJson() => "{'password':'goodbye'}"
maskedJson = jsonBlob.toJson(true) => "{'password':'******'}"

Custom Printer

A custom printer can be defined that allows outputting the json to an Appendable source. For example a FilePrinter could be used to write the JSON to a file.

class FilePrinter(_printWriter: PrintWriter, override val mask: Boolean) : JsonBlob.Printer {
  private val printWriter = _printWriter

  override fun append(p0: CharSequence?): Appendable {
    printWriter.append(p0)
    return this
  }

  override fun append(p0: CharSequence?, p1: Int, p2: Int): Appendable {
    printWriter.append(p0, p1, p2)
    return this
  }

  override fun append(p0: Char): Appendable {
    printWriter.append(p0)
    return this
  }
}

val blob = JsonBlob.obj(kv("a", mask(v("asd"), "***")))

File("path-to-file").printWriter().use { blob.toJson(FilePrinter(it, false)) }
File("path-to-masked-file").printWriter().use { blob.toJson(FilePrinter(it, true)) }

Publishing artifacts

The json-blob artifact is published to jcenter. To publish the following command need to be run:

./gradlew bintrayUpload

Release

This is using the Gradle release plugin https://github.com/researchgate/gradle-release

The release is configured to publish the artifact to Bintray and depends on the bintrayUpload task.

./gradlew release