Java中是否有与groovy的ConfigSlurper等效的类？

Question

Below is a small example that I generally use in groovy, but I want something similar in java.

Configuration file

datastore{
    oracle{
        host="localhost"
        port=1521
        dbname="orcl"
    }
    db2{
        host="localhost"
        port=12807
        dbname="sppd"
    }
}

Groovy

public class Configuration {

    public static final def cfg = new ConfigSlurper().parse(new File("configuration").toURL())

    static main(args) {
        println cfg.datastore.oracle.host
        println cfg.datastore.db2.host
    }

}

Answer 1

I'm guessing that you're wanting to access a property by its full path, eg datastore.oracle.host from Java like you can in Groovy. If so, do this:

ConfigObject config = new ConfigSlurper().parse(new File("configuration").toURL());
Map flattenedConfig = config.flatten();
String oracleHost = (String) flattenedConfig.get("datastore.oracle.host");

Better than Java properties because the type is maintained. From a Groovy User list post .

Answer 2

That is too much dynamic groovyness, but can be expressed in XML, properties, etc. You can try Common Configuration , which would express the same data:

<?xml version="1.0" encoding="ISO-8859-1" ?>
<gui-definition>
  <colors>
    <background>#808080</background>
    <text>#000000</text>
    <header>#008000</header>
    <link normal="#000080" visited="#800080"/>
    <default>${colors.header}</default>
  </colors>
</gui-definition>

And read with:

XMLConfiguration config = new XMLConfiguration("tables.xml");
String backColor = config.getString("colors.background");
String textColor = config.getString("colors.text");
String linkNormal = config.getString("colors.link[@normal]");

You can also give a try to PropertyConfiguration :

# Properties definining the GUI
colors.background = #FFFFFF
colors.foreground = #000080

window.width = 500
window.height = 300

Loaded with:

Configuration config = new PropertiesConfiguration("usergui.properties");
String backColor = config.getString("colors.background");