G2-1888 Generalized injection API

ha-inject/.gitignore

@@ -0,0 +1,6 @@
+/.project
+/.classpath
+/.settings/
+/target/
+/bulldozer-temp.json
+/.factorypath

ha-inject/pom.xml

@@ -0,0 +1,16 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+
+	<artifactId>ha-inject</artifactId>
+
+	<parent>
+		<groupId>com.g2forge.habitat</groupId>
+		<artifactId>ha-project</artifactId>
+		<version>0.0.8-SNAPSHOT</version>
+		<relativePath>../ha-project/pom.xml</relativePath>
+	</parent>
+
+	<name>Habitat Inject</name>
+	<description>An API for value injection.</description>
+</project>

ha-inject/src/main/java/com/g2forge/habitat/inject/IInjectedValue.java

@@ -0,0 +1,5 @@
+package com.g2forge.habitat.inject;
+
+public interface IInjectedValue<T> {
+	public InjectedValueDescriptor<T> getDescriptor();
+}

ha-inject/src/main/java/com/g2forge/habitat/inject/InjectedValueDescriptor.java

@@ -0,0 +1,26 @@
+package com.g2forge.habitat.inject;
+
+import com.g2forge.alexandria.java.type.ref.ITypeRef;
+
+import lombok.Builder;
+import lombok.Data;
+import lombok.RequiredArgsConstructor;
+
+@Data
+@Builder(toBuilder = true)
+@RequiredArgsConstructor
+public class InjectedValueDescriptor<T> {
+	protected final String id;
+
+	protected final ITypeRef<T> type;
+
+	protected final T fallback;
+
+	public InjectedValueDescriptor(Class<?> owner, String name, ITypeRef<T> type, T fallback) {
+		this(owner.getName() + "." + name, type, fallback);
+	}
+
+	public InjectedValueDescriptor(Class<T> type, T fallback) {
+		this(type.getName(), ITypeRef.of(type), fallback);
+	}
+}

ha-inject/src/main/java/com/g2forge/habitat/inject/MapInjectedValue.java

@@ -0,0 +1,24 @@
+package com.g2forge.habitat.inject;
+
+import java.util.Map;
+
+import lombok.Builder;
+import lombok.Data;
+import lombok.RequiredArgsConstructor;
+
+@Data
+@Builder(toBuilder = true)
+@RequiredArgsConstructor
+public class MapInjectedValue<T> implements IInjectedValue<T> {
+	protected final InjectedValueDescriptor<T> descriptor;
+
+	public T get(Map<?, ?> map) {
+		if ((map != null) && map.containsKey(getDescriptor().getId())) return getDescriptor().getType().cast(map.get(getDescriptor().getId()));
+		return getDescriptor().getFallback();
+	}
+
+	public Map<? super String, ? super T> inject(Map<? super String, ? super T> map, T value) {
+		map.put(getDescriptor().getId(), value);
+		return map;
+	}
+}

pom.xml

@@ -20,5 +20,6 @@
 		<module>ha-trace</module>
 		<module>ha-metadata</module>
 		<module>ha-plugin</module>
+		<module>ha-inject</module>
 	</modules>
 </project>