Package org.apache.juneau.marshall.hocon

Class HoconResolver

java.lang.Object

org.apache.juneau.marshall.hocon.HoconResolver

public class HoconResolver
extends Object

Resolves ${var} and ${?var} substitutions in the parsed HOCON tree.

Resolution algorithm: single-pass depth-first over the tree. Substitutions reference paths in the root object (e.g., ${database.host}). Optional substitutions (${?var}) are silently removed if the path does not exist. Required substitutions (${var}) throw if the path is missing. Circular references are detected and cause an error.

See Also:

• HOCON Specification

Constructor Summary

Constructors

Constructor	Description
HoconResolver(HoconValue.HoconObject root)	Constructor.

Method Summary

Modifier and Type	Method	Description
HoconValue	lookup(String path)	Looks up a dotted path in the root object.
void	resolve()	Resolves all substitutions in-place in the tree.
HoconValue	resolveConcatWithLookup(HoconValue.HoconConcat concat, Function<String,HoconValue> lookup)	Resolves a concatenation value with a custom lookup (for self-referential substitution).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

HoconResolver

public HoconResolver(HoconValue.HoconObject root)

Constructor.

Parameters:

root - The root HOCON object (after parsing, before resolution).
Must not be null (resolve() dereferences it).

Method Details

resolve

public void resolve()

Resolves all substitutions in-place in the tree.

Throws:

RuntimeException - If a required substitution path is missing or circular.

lookup

public HoconValue lookup(String path)

Looks up a dotted path in the root object.

Parameters:

path - The path (e.g., "database.host").
Can be null (returns null).

Returns:

The value at that path, or null if the path is null, blank, or does not resolve to an existing value.

resolveConcatWithLookup

public HoconValue resolveConcatWithLookup(HoconValue.HoconConcat concat,
 Function<String,HoconValue> lookup)

Resolves a concatenation value with a custom lookup (for self-referential substitution). When the concat contains ${path}, the lookup is used instead of the root object. This allows path = ${path}"/bin" to append to the previous value.

Parameters:

concat - The concatenation to resolve.
Must not be null.

lookup - Custom lookup; for path X returns the value to use (e.g. previous value for self-ref).
Must not be null.

Returns:

The resolved string value.