From 1e1f821e46a45002c8db02bb65fe91a7d4d5221f Mon Sep 17 00:00:00 2001
From: "chen.ma" <machencoding@163.com>
Date: Sun, 11 Jul 2021 00:57:21 +0800
Subject: [PATCH] =?UTF-8?q?feat:=20=E6=8F=90=E4=BE=9B=E5=8A=A8=E6=80=81?=
 =?UTF-8?q?=E7=BA=BF=E7=A8=8B=E6=B1=A0=20SPI=20=E5=85=AC=E5=85=B1=E7=BB=84?=
 =?UTF-8?q?=E4=BB=B6.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../starter/spi/DynamicTpServiceLoader.java   | 48 +++++++++++++++++++
 .../ServiceLoaderInstantiationException.java  | 16 +++++++
 2 files changed, 64 insertions(+)
 create mode 100644 dynamic-threadpool-spring-boot-starter/src/main/java/io/dynamic/threadpool/starter/spi/DynamicTpServiceLoader.java
 create mode 100644 dynamic-threadpool-spring-boot-starter/src/main/java/io/dynamic/threadpool/starter/spi/exception/ServiceLoaderInstantiationException.java

diff --git a/dynamic-threadpool-spring-boot-starter/src/main/java/io/dynamic/threadpool/starter/spi/DynamicTpServiceLoader.java b/dynamic-threadpool-spring-boot-starter/src/main/java/io/dynamic/threadpool/starter/spi/DynamicTpServiceLoader.java
new file mode 100644
index 00000000..9bfbe9f2
--- /dev/null
+++ b/dynamic-threadpool-spring-boot-starter/src/main/java/io/dynamic/threadpool/starter/spi/DynamicTpServiceLoader.java
@@ -0,0 +1,48 @@
+package io.dynamic.threadpool.starter.spi;
+
+import io.dynamic.threadpool.starter.spi.exception.ServiceLoaderInstantiationException;
+
+import java.util.*;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Collectors;
+
+/**
+ * Dynamic ThreadPool Service Loader.
+ *
+ * @author chen.ma
+ * @date 2021/7/10 23:45
+ */
+public class DynamicTpServiceLoader {
+
+    private static final Map<Class<?>, Collection<Object>> SERVICES = new ConcurrentHashMap();
+
+    public static void register(final Class<?> serviceInterface) {
+        if (!SERVICES.containsKey(serviceInterface)) {
+            SERVICES.put(serviceInterface, load(serviceInterface));
+        }
+    }
+
+    private static <T> Collection<Object> load(final Class<T> serviceInterface) {
+        Collection<Object> result = new LinkedList<>();
+        for (T each : ServiceLoader.load(serviceInterface)) {
+            result.add(each);
+        }
+        return result;
+    }
+
+    public static <T> Collection<T> getSingletonServiceInstances(final Class<T> service) {
+        return (Collection<T>) SERVICES.getOrDefault(service, Collections.emptyList());
+    }
+
+    public static <T> Collection<T> newServiceInstances(final Class<T> service) {
+        return SERVICES.containsKey(service) ? SERVICES.get(service).stream().map(each -> (T) newServiceInstance(each.getClass())).collect(Collectors.toList()) : Collections.emptyList();
+    }
+
+    private static Object newServiceInstance(final Class<?> clazz) {
+        try {
+            return clazz.newInstance();
+        } catch (final InstantiationException | IllegalAccessException ex) {
+            throw new ServiceLoaderInstantiationException(clazz, ex);
+        }
+    }
+}
diff --git a/dynamic-threadpool-spring-boot-starter/src/main/java/io/dynamic/threadpool/starter/spi/exception/ServiceLoaderInstantiationException.java b/dynamic-threadpool-spring-boot-starter/src/main/java/io/dynamic/threadpool/starter/spi/exception/ServiceLoaderInstantiationException.java
new file mode 100644
index 00000000..718d68bf
--- /dev/null
+++ b/dynamic-threadpool-spring-boot-starter/src/main/java/io/dynamic/threadpool/starter/spi/exception/ServiceLoaderInstantiationException.java
@@ -0,0 +1,16 @@
+package io.dynamic.threadpool.starter.spi.exception;
+
+/**
+ * Service loader instantiation exception.
+ *
+ * @author chen.ma
+ * @date 2021/7/10 23:48
+ */
+public class ServiceLoaderInstantiationException extends RuntimeException {
+
+    public ServiceLoaderInstantiationException(final Class<?> clazz, final Exception cause) {
+        super(String.format("Can not find public default constructor for SPI class `%s`", clazz.getName()), cause);
+    }
+
+}
+