Issue #4340 - remove TypeUtil.load and use flatMap() on streams instead

Signed-off-by: Lachlan Roberts <lachlan@webtide.com>

jetty-alpn/jetty-alpn-client/src/main/java/org/eclipse/jetty/alpn/client/ALPNClientConnectionFactory.java

@@ -54,7 +54,7 @@ public class ALPNClientConnectionFactory extends NegotiatingClientConnectionFact
         IllegalStateException failure = new IllegalStateException("No Client ALPNProcessors!");
 
         // Use a for loop on iterator so load exceptions can be caught and ignored
-        TypeUtil.load(ServiceLoader.load(Client.class)).forEach((processor) ->
+        ServiceLoader.load(Client.class).stream().flatMap(TypeUtil::providerMap).forEach((processor) ->
         {
             try
             {

jetty-alpn/jetty-alpn-server/src/main/java/org/eclipse/jetty/alpn/server/ALPNServerConnectionFactory.java

@@ -51,7 +51,7 @@ public class ALPNServerConnectionFactory extends NegotiatingServerConnectionFact
 
         IllegalStateException failure = new IllegalStateException("No Server ALPNProcessors!");
         // Use a for loop on iterator so load exceptions can be caught and ignored
-        TypeUtil.load(ServiceLoader.load(Server.class)).forEach((processor) ->
+        ServiceLoader.load(Server.class).stream().flatMap(TypeUtil::providerMap).forEach((processor) ->
         {
             try
             {

jetty-annotations/src/main/java/org/eclipse/jetty/annotations/AnnotationConfiguration.java

@@ -812,7 +812,7 @@ public class AnnotationConfiguration extends AbstractConfiguration
         long start = 0;
         if (LOG.isDebugEnabled())
             start = System.nanoTime();
-        List<ServletContainerInitializer> scis = TypeUtil.load(ServiceLoader.load(ServletContainerInitializer.class)).collect(Collectors.toList());
+        List<ServletContainerInitializer> scis = ServiceLoader.load(ServletContainerInitializer.class).stream().flatMap(TypeUtil::providerMap).collect(Collectors.toList());
         if (LOG.isDebugEnabled())
             LOG.debug("Service loaders found in {}ms", (TimeUnit.MILLISECONDS.convert((System.nanoTime() - start), TimeUnit.NANOSECONDS)));
 

jetty-http/src/main/java/org/eclipse/jetty/http/PreEncodedHttpField.java

@@ -44,7 +44,8 @@ public class PreEncodedHttpField extends HttpField
     static
     {
         List<HttpFieldPreEncoder> encoders = new ArrayList<>();
-        TypeUtil.load(ServiceLoader.load(HttpFieldPreEncoder.class))
+        ServiceLoader.load(HttpFieldPreEncoder.class).stream()
+            .flatMap(TypeUtil::providerMap)
             .filter(encoder -> index(encoder.getHttpVersion()) >= 0)
             .forEach(encoders::add);
 

jetty-security/src/main/java/org/eclipse/jetty/security/SecurityHandler.java

@@ -77,7 +77,8 @@ public abstract class SecurityHandler extends HandlerWrapper implements Authenti
 
     static
     {
-        TypeUtil.load(ServiceLoader.load(Authenticator.Factory.class)).forEach(__knownAuthenticatorFactories::add);
+        ServiceLoader.load(Authenticator.Factory.class).stream()
+            .flatMap(TypeUtil::providerMap).forEach(__knownAuthenticatorFactories::add);
         __knownAuthenticatorFactories.add(new DefaultAuthenticatorFactory());
     }
 

jetty-util/src/main/java/org/eclipse/jetty/util/TypeUtil.java

@@ -41,10 +41,10 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
-import java.util.Objects;
 import java.util.Optional;
 import java.util.ServiceConfigurationError;
 import java.util.ServiceLoader;
+import java.util.function.Function;
 import java.util.stream.Stream;
 
 import org.eclipse.jetty.util.log.Log;
@@ -757,27 +757,23 @@ public class TypeUtil
     }
 
     /**
-     * Uses the {@link ServiceLoader} to return a Stream of the service providers which does not throw.
-     * If loading a service type throws {@link ServiceConfigurationError},
-     * it warns and continues iterating through the service loader.
+     * Used on a {@link ServiceLoader#stream()} with {@link Stream#flatMap(Function)},
+     * so that in the case a {@link ServiceConfigurationError} is thrown it warns and
+     * continues iterating through the service loader.
      * @param <T> The class of the service type.
-     * @param serviceLoader The service loader to use.
+     * @param provider The service provider to instantiate.
      * @return a stream of the loaded service providers.
      */
-    public static <T> Stream<T> load(ServiceLoader<T> serviceLoader)
+    public static <T> Stream<T> providerMap(ServiceLoader.Provider<T> provider)
     {
-        return serviceLoader.stream().map((provider) ->
+        try
         {
-            try
-            {
-                // Attempt to load service, will either return a service, throw an error, or return null.
-                return provider.get();
-            }
-            catch (ServiceConfigurationError error)
-            {
-                LOG.warn("Service Provider failed to load", error);
-            }
-            return null;
-        }).filter(Objects::nonNull);
+            return Stream.of(provider.get());
+        }
+        catch (ServiceConfigurationError error)
+        {
+            LOG.warn("Service Provider failed to load", error);
+            return Stream.empty();
+        }
     }
 }

jetty-util/src/main/java/org/eclipse/jetty/util/security/Credential.java

@@ -44,7 +44,7 @@ public abstract class Credential implements Serializable
 {
     private static final long serialVersionUID = -7760551052768181572L;
     private static final Logger LOG = Log.getLogger(Credential.class);
-    private static final List<CredentialProvider> CREDENTIAL_PROVIDERS = TypeUtil.load(ServiceLoader.load(CredentialProvider.class)).collect(Collectors.toList());
+    private static final List<CredentialProvider> CREDENTIAL_PROVIDERS = ServiceLoader.load(CredentialProvider.class).stream().flatMap(TypeUtil::providerMap).collect(Collectors.toList());
 
     /**
      * Check a credential

jetty-webapp/src/main/java/org/eclipse/jetty/webapp/Configurations.java

@@ -75,7 +75,7 @@ public class Configurations extends AbstractList<Configuration> implements Dumpa
     {
         if (__known.isEmpty())
         {
-            TypeUtil.load(ServiceLoader.load(Configuration.class)).forEach(configuration ->
+            ServiceLoader.load(Configuration.class).stream().flatMap(TypeUtil::providerMap).forEach(configuration ->
             {
                 if (!configuration.isAvailable())
                 {

jetty-xml/src/main/java/org/eclipse/jetty/xml/XmlConfiguration.java

@@ -96,7 +96,8 @@ public class XmlConfiguration
         {
             ArrayList.class, HashSet.class, Queue.class, List.class, Set.class, Collection.class
         };
-    private static final List<ConfigurationProcessorFactory> PROCESSOR_FACTORIES = TypeUtil.load(ServiceLoader.load(ConfigurationProcessorFactory.class)).collect(Collectors.toList());
+    private static final List<ConfigurationProcessorFactory> PROCESSOR_FACTORIES = ServiceLoader.load(ConfigurationProcessorFactory.class)
+        .stream().flatMap(TypeUtil::providerMap).collect(Collectors.toList());
     private static final XmlParser PARSER = initParser();
     private static final Comparator<Executable> EXECUTABLE_COMPARATOR = (o1, o2) ->
     {