io.qameta.allure.kotlin.util.ServiceLoaderUtils.kt Maven / Gradle / Ivy

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package io.qameta.allure.kotlin.util

import java.util.*
import java.util.logging.Logger

/**
 * Internal service loader util.
 *
 * @see ServiceLoader
 *
 * @since 2.0
 */
object ServiceLoaderUtils {
    private val LOGGER: Logger = loggerFor()
    /**
     * Load implementation by given type.
     *
     * @param          type of implementation.
     * @param type        the type of implementation to load.
     * @param classLoader the class loader to search for implementations.
     * @return loaded implementations.
     */
    @JvmStatic
    fun  load(type: Class, classLoader: ClassLoader): List {
        val loaded: MutableList = ArrayList()
        val iterator: Iterator = ServiceLoader.load(type, classLoader).iterator()
        while (iterator.hasNextSafely()) {
            try {
                val next = iterator.next()
                loaded.add(next)
                LOGGER.debug("Found $type")
            } catch (e: Exception) {
                LOGGER.error("Could not load $type: $e", e)
            }
        }
        return loaded
    }

    /**
     * Safely check for iterator.hasNext().
     *
     * @return `true` if the iteration has more elements, false otherwise
     */
    private fun Iterator<*>.hasNextSafely(): Boolean {
        return try { /* Throw a ServiceConfigurationError if a provider-configuration file violates the specified format,
            or if it names a provider class that cannot be found and instantiated, or if the result of
            instantiating the class is not assignable to the service type, or if any other kind of exception
            or error is thrown as the next provider is located and instantiated.
            @see http://docs.oracle.com/javase/7/docs/api/java/util/ServiceLoader.html#iterator()
            */
            hasNext()
        } catch (e: Exception) {
            LOGGER.error("iterator.hasNext() failed", e)
            false
        }
    }

}