Scala Typesafe Config 打印文件路径、键和值

Question

Trying to find a very simple and clean way to just print the filepath and keys along with values that are present inside my application.conf file when using typesafe config library in scala. I have found many examples that almost do what I need but can't figure out how to properly filter down to the keys only in file. For example, I tried below variations but it prints too many values along with what I need such as akka etc which I'm not sure where it even gets from.

  val keys = propReader.getConfig().entrySet().map(_.getKey)
  val values = propReader.getConfig().entrySet().map(_.getValue)
  for (key <- keys) if (key.contains("mykey"))
    for (value <- values) println(key, value)

Also tried but also prints too much

  private def listingPathsAndKeys(config: Config) {
    import scala.collection.JavaConversions._
    def display(codeAsString: String)(body: => Any) {
      println(body)
    }
    display("config.root().keySet()") {
      config.root().render(ConfigRenderOptions.concise())

    }
  }
  listingPathsAndKeys(propReader.getConfig())

this gives me the root level keys that ideally I would like to filter to a specific root in my file and just print the keys/values:

config.root().keySet()

Answer 1

This answer is based on Typesafe Config 1.3.1

To get the path of your config file first get a subtree existing in your application.conf (check @fcat's answer) returning the Config object and then use the origin() method on it. You will get the ConfigOrigin object with the url field that points to your application.conf :

config.getConfig("sample-configuration").origin()

In other words - this will return the origin of the configuration subtree, which in your case is application.conf file. However, in some cases ConfigOrigin.url can be null.

The code you presented does not contain any information on how you actually load the configuration. From what you described I assume it is ConfigFactory.load() in which case the library uses a bunch of defaults that load different configs present in the classpath. That is why you get some keys not existing in your application.conf . And since ConfigFactory.load() actually returns a merged Config from what it can find in the classpath, it is impossible to get its "merged" origin.

Answer 2

I don't know how to print the path of application.conf in use. However, I can recommend a good approach for printing key-value pairs:

1. In your application.conf enclose your parameters in a specified namespace.

application.conf:

 sample-configuration = {
    key1 = "value1"
    key2 = "value2"
 }

2. In your application load the configuration and print only the parameters in the specified namespace:

val config: Config = ConfigFactory.load()
val sampleConfig: Config = config.getConfig("sample-configuration")
println(sampleConfig)

Answer 3

Was trying to do the same thing to figure out which value is from which config file. An alternative way is to write a script that appends the current file path to each of the value, then dump out the merged config file and you can tell which file the value is from.

Answer 4

You can use this tool: Hocon Config Printer

It will show you the 'final' configuration file, and also the file from where each setting is read from.

Example:

hocon-config-printer conf/application.conf  -verbose

Output:

    {
    # conf/akka.conf: 1-5
    "akka" : {
        # conf/akka.conf: 9
        "actor" : {
            # conf/akka.conf: 10
            "default-dispatcher" : {
                # conf/akka.conf: 11
                "fork-join-executor" : {
                    # conf/akka.conf: 12
                    "parallelism-factor" : 3,
                    # conf/akka.conf: 14
                    "parallelism-max" : 200,
                    # conf/akka.conf: 13
                    "parallelism-min" : 10
...