Merge pull request #3191 from jglick/ServiceLoader

Deprecating Service in favor of ServiceLoader

core/src/main/java/hudson/PluginManager.java

@@ -120,7 +120,6 @@ import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.List;
-import java.util.ListIterator;
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeMap;
@@ -144,6 +143,7 @@ import hudson.util.FormValidation;
 import java.io.ByteArrayInputStream;
 import java.net.JarURLConnection;
 import java.net.URLConnection;
+import java.util.ServiceLoader;
 import java.util.jar.JarEntry;
 
 import static java.util.logging.Level.FINE;
@@ -1195,7 +1195,9 @@ public abstract class PluginManager extends AbstractModelObject implements OnMas
     /**
      * Discover all the service provider implementations of the given class,
      * via <tt>META-INF/services</tt>.
+     * @deprecated Use {@link ServiceLoader} instead, or (more commonly) {@link ExtensionList}.
      */
+    @Deprecated
     public <T> Collection<Class<? extends T>> discover( Class<T> spi ) {
         Set<Class<? extends T>> result = new HashSet<Class<? extends T>>();
 

core/src/main/java/hudson/init/InitStrategy.java

@@ -17,7 +17,8 @@ import hudson.PluginManager;
 import jenkins.util.SystemProperties;
 import hudson.util.DirScanner;
 import hudson.util.FileVisitor;
-import hudson.util.Service;
+import java.util.Iterator;
+import java.util.ServiceLoader;
 
 /**
  * Strategy pattern of the various key decision making during the Jenkins initialization.
@@ -113,11 +114,12 @@ public class InitStrategy {
      * Obtains the instance to be used.
      */
     public static InitStrategy get(ClassLoader cl) throws IOException {
-        List<InitStrategy> r = Service.loadInstances(cl, InitStrategy.class);
-        if (r.isEmpty())    return new InitStrategy();      // default
-
-        InitStrategy s = r.get(0);
-        LOGGER.fine("Using "+s+" as InitStrategy");
+        Iterator<InitStrategy> it = ServiceLoader.load(InitStrategy.class, cl).iterator();
+        if (!it.hasNext()) {
+            return new InitStrategy(); // default
+        }
+        InitStrategy s = it.next();
+        LOGGER.log(Level.FINE, "Using {0} as InitStrategy", s);
         return s;
     }
 

core/src/main/java/hudson/util/Service.java

@@ -31,6 +31,7 @@ import java.util.Collection;
 import java.util.Enumeration;
 import java.util.List;
 import java.util.ArrayList;
+import java.util.ServiceLoader;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import static java.util.logging.Level.WARNING;
@@ -39,11 +40,10 @@ import static java.util.logging.Level.WARNING;
  * Load classes by looking up <tt>META-INF/services</tt>.
  *
  * @author Kohsuke Kawaguchi
+ * @deprecated use {@link ServiceLoader} instead.
  */
+@Deprecated
 public class Service {
-    /**
-     * Poorman's clone of JDK6 ServiceLoader.
-     */
     public static <T> List<T> loadInstances(ClassLoader classLoader, Class<T> type) throws IOException {
         List<T> result = new ArrayList<T>();
 

core/src/main/java/jenkins/InitReactorRunner.java

 package jenkins;
 
+import com.google.common.collect.Lists;
 import jenkins.util.SystemProperties;
 import hudson.init.InitMilestone;
 import hudson.init.InitReactorListener;
 import hudson.util.DaemonThreadFactory;
 import hudson.util.NamingThreadFactory;
-import hudson.util.Service;
 import jenkins.model.Configuration;
 import jenkins.model.Jenkins;
 import org.jvnet.hudson.reactor.Milestone;
@@ -16,6 +16,7 @@ import org.jvnet.hudson.reactor.Task;
 
 import java.io.IOException;
 import java.util.List;
+import java.util.ServiceLoader;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.LinkedBlockingQueue;
@@ -59,7 +60,7 @@ public class InitReactorRunner {
      * As such there's no way for plugins to participate into this process.
      */
     private ReactorListener buildReactorListener() throws IOException {
-        List<ReactorListener> r = (List) Service.loadInstances(Thread.currentThread().getContextClassLoader(), InitReactorListener.class);
+        List<ReactorListener> r = Lists.newArrayList(ServiceLoader.load(InitReactorListener.class, Thread.currentThread().getContextClassLoader()));
         r.add(new ReactorListener() {
             final Level level = Level.parse( Configuration.getStringConfigParameter("initLogLevel", "FINE") );
             public void onTaskStarted(Task t) {

core/src/main/java/jenkins/security/ConfidentialStore.java

@@ -4,7 +4,6 @@ import hudson.Extension;
 import hudson.Lookup;
 import hudson.init.InitMilestone;
 import hudson.util.Secret;
-import hudson.util.Service;
 import jenkins.model.Jenkins;
 import org.kohsuke.MetaInfServices;
 
@@ -12,7 +11,9 @@ import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
 import java.io.IOException;
 import java.security.SecureRandom;
-import java.util.List;
+import java.util.Iterator;
+import java.util.ServiceConfigurationError;
+import java.util.ServiceLoader;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -68,10 +69,11 @@ public abstract class ConfidentialStore {
         ConfidentialStore cs = lookup.get(ConfidentialStore.class);
         if (cs==null) {
             try {
-                List<ConfidentialStore> r = (List) Service.loadInstances(ConfidentialStore.class.getClassLoader(), ConfidentialStore.class);
-                if (!r.isEmpty())
-                    cs = r.get(0);
-            } catch (IOException e) {
+                Iterator<ConfidentialStore> it = ServiceLoader.load(ConfidentialStore.class, ConfidentialStore.class.getClassLoader()).iterator();
+                if (it.hasNext()) {
+                    cs = it.next();
+                }
+            } catch (ServiceConfigurationError e) {
                 LOGGER.log(Level.WARNING, "Failed to list up ConfidentialStore implementations",e);
                 // fall through
             }