Implement service loader

Author: reactivestudio

convertible-core/src/main/kotlin/pro/vlprojects/convertible/core/processor/ConvertibleProcessor.kt

@@ -12,19 +12,17 @@ import com.google.devtools.ksp.validate
 import com.squareup.kotlinpoet.FileSpec
 import pro.vlprojects.convertible.core.annotation.Convertible
 import pro.vlprojects.convertible.core.definition.ConvertibleDefinition
-import pro.vlprojects.convertible.core.strategy.ConvertibleStrategy
+import pro.vlprojects.convertible.core.strategy.ConvertibleStrategyLoader
 import java.io.OutputStreamWriter
-import java.util.ServiceLoader
 
 class ConvertibleProcessor(
 	private val generator: CodeGenerator,
 	private val logger: KSPLogger,
 ) : SymbolProcessor {
 
-	private val strategies = ServiceLoader
-		.load(ConvertibleStrategy::class.java)
-		.toList()
-		.onEach { strategy -> logger.info("Loaded strategy: ${strategy.javaClass.canonicalName}") }
+	private val strategies = ConvertibleStrategyLoader(logger)
+		.load()
+		.also { logger.info("${it.size} strategies found for code generating") }
 
 	private val definitions = mutableListOf<ConvertibleDefinition>()
 	private val visitor = ConvertibleVisitor(definitions)

convertible-core/src/main/kotlin/pro/vlprojects/convertible/core/strategy/ConvertibleStrategyLoader.kt

@@ -0,0 +1,66 @@
+package pro.vlprojects.convertible.core.strategy
+
+import com.google.devtools.ksp.processing.KSPLogger
+import java.net.URL
+
+class ConvertibleStrategyLoader(
+	private val logger: KSPLogger,
+) {
+
+	companion object {
+		const val RESOURCE_NAME = "META-INF/services/pro.vlprojects.convertible.core.strategy.ConvertibleStrategy"
+	}
+
+	fun load(): List<ConvertibleStrategy> {
+
+		val classLoader = Thread.currentThread().contextClassLoader
+		val result = mutableListOf<ConvertibleStrategy>()
+
+		readResources(classLoader)
+			.forEach { resource ->
+				logger.info("Found resource: $resource")
+
+				readClassNames(resource)
+					.forEach { className ->
+						logger.info("Found class: $className")
+
+						runCatching { createStrategy(className, classLoader) }
+							.onFailure { logger.error("Failed to create strategy for class $className. Details: ${it.message}") }
+							.onSuccess {
+								result.add(it)
+								logger.info("Created strategy for class $className")
+							}
+					}
+			}
+
+		return result
+	}
+
+	private fun readResources(classLoader: ClassLoader) = classLoader
+		.runCatching { getResources(RESOURCE_NAME) }
+		.onFailure { logger.error("Failed to read resources $RESOURCE_NAME. Details: ${it.message}") }
+		.getOrNull()
+		?.toList()
+		?: emptyList()
+
+	private fun readClassNames(resource: URL) = resource
+		.runCatching {
+			openStream()
+				.bufferedReader()
+				.readLines()
+				.map { it.trim() }
+				.filter { it.isNotBlank() && it.startsWith("#").not() }
+		}
+		.onFailure { logger.error("Failed to read resource $resource. Details: ${it.message}") }
+		.getOrDefault(emptyList())
+
+	private fun createStrategy(className: String, classLoader: ClassLoader): ConvertibleStrategy {
+		val clazz = Class.forName(className, true, classLoader)
+
+		require(ConvertibleStrategy::class.java.isAssignableFrom(clazz)) {
+			"Class $className is not assignable to ${ConvertibleStrategy::class.java.canonicalName}"
+		}
+
+		return clazz.getDeclaredConstructor().newInstance() as ConvertibleStrategy
+	}
+}

gradle.properties

@@ -1,4 +1,4 @@
 group=pro.vlprojects
-version=0.0.5
+version=0.0.6
 kotlin.version=2.1.21
 kotlin.code.style=official