vd-from-properties-parser

A lightweight, reflection-based utility to populate Java objects from Properties. Supports nested structures, collections, maps, interfaces (via class property), and uses FromStringParsers to support string-based conversions for individual properties.

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Features

• Populate object fields via Properties
• Supports:
  • Collections (inline or indexed)
  • Maps (inline or recursive)
  • Nested objects (recursively parsed)
  • Polymorphism (via .class property)
• Works out of the box — no annotations or frameworks required
• Extensible with custom parsers via SPI (see vd-from-string-parser)

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Comparison

Feature	vd-from-properties-parser	Spring Boot	Apache Commons Configuration	Owner
Works with plain Properties	✅	❌	✅	✅
Deep/nested object support	✅	✅	❌	❌
Custom parsers via SPI	✅	❌	❌	❌
Reflection-based (no annotations)	✅	❌	❌	❌
Lightweight (no framework)	✅	❌	✅	✅

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Examples

Collection

Inline:

collection=a,b,c

Using integer index:

collection.0=a
collection.1=b
collection.3=c

Using any index:

collection.a=a
collection.b=b
collection.z=c

With recursion:

collection.0.string=a
collection.1.string=b

View classes

MyObject

public class MyObject {
    public Collection<MySubObject> collection;
}

MySubObject

public class MySubObject {
    public String string;
}

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Map

Inline:

map.abc=123

Using any index with explicit key and value:

map.0.key=abc
map.0.value=123

With recursion:

map.0.key.string=a
map.0.value.string=1

View classes

MyObject

public class MyObject {
    public Map<MySubObject, MySubObject> map;
}

MySubObject

public class MySubObject {
    public String string;
}

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Inheritance

Specify implementing class for an interface:

object.class=MyImplementation
object.string=abc

View classes

MyInterface

public interface MyInterface {}

MyImplementation

public class MyImplementation implements MyInterface {
    public String string;
}