Java Properties format

The Java Properties class, java.util.Properties, is like a Java Map of Java String key and value pairs. The Java Properties class can write the key, value pairs to a properties file on disk, and read the properties back in again. This is an often used mechanism for storing simple configuration properties for Java applications.

Dependencies

DataTree API supports 2 Java Property reader/writer implementations. The default (built-in) Property adapter has no dependencies.

import io.datatree.Tree;

// Build a small document (an object with a nested array):
Tree document = new Tree();
document.put("name", "Alice");
document.put("age", 30);
document.putList("languages").add("Java").add("Go");

// Convert the Tree to a Java Properties string (the dependency-free
// built-in adapter is the default):
String properties = document.toString("properties");
System.out.println(properties);

The printed output. The flat key/value model has no arrays, so list elements become numbered (1-based) keys:

name=Alice
age=30
languages.1=Java
languages.2=Go

Parse a Java Properties string back into a Tree with the "properties" format name:

Tree parsed = new Tree(properties, "properties");
int age = parsed.get("age", 0);   // 30

If there is more than one Promerties implementation on classpath, the preferred implementation is adjustable with the following System Properties:

// Using Jackson API:
-Ddatatree.properties.reader=io.datatree.dom.adapters.PropertiesJackson
-Ddatatree.properties.writer=io.datatree.dom.adapters.PropertiesJackson

// Using built-in API:
-Ddatatree.properties.reader=io.datatree.dom.adapters.PropertiesBuiltin
-Ddatatree.properties.writer=io.datatree.dom.adapters.PropertiesBuiltin

Required dependencies of Java Property adapters

API Name	Adapter Class	Dependency
Jackson Properties	PropertiesJackson	group: 'com.fasterxml.jackson.dataformat', name: 'jackson-dataformat-properties', version: '2.19.0' (opens new window)
Built-in Properties	PropertiesBuiltin	-