loadbalancer: deprecate RoundRobinLoadBalancer types (#3149)

Motivation:

We're switching over to the new load balancer API's, but we still
have the older API's sitting around.

Modifications:

Deprecate the old API's and direct users to the new.

servicetalk-loadbalancer/src/main/java/io/servicetalk/loadbalancer/DelegatingRoundRobinLoadBalancerBuilder.java

@@ -28,7 +28,9 @@
  *
  * @param <ResolvedAddress> The resolved address type.
  * @param <C> The type of connection.
+ * @deprecated use {@link DelegatingLoadBalancerBuilder} instead.
  */
+@Deprecated // FIXME: 0.43 - Remove in favor of the DefaultLoadBalancer types
 public class DelegatingRoundRobinLoadBalancerBuilder<ResolvedAddress, C extends LoadBalancedConnection>
         implements RoundRobinLoadBalancerBuilder<ResolvedAddress, C> {
 

servicetalk-loadbalancer/src/main/java/io/servicetalk/loadbalancer/RoundRobinLoadBalancer.java

@@ -95,6 +95,7 @@
  * @param <ResolvedAddress> The resolved address type.
  * @param <C> The type of connection.
  */
+// FIXME: 0.43 - remove deprecated class
 final class RoundRobinLoadBalancer<ResolvedAddress, C extends LoadBalancedConnection>
         implements TestableLoadBalancer<ResolvedAddress, C> {
 

servicetalk-loadbalancer/src/main/java/io/servicetalk/loadbalancer/RoundRobinLoadBalancerBuilder.java

@@ -63,7 +63,10 @@
  * @param <ResolvedAddress> The resolved address type.
  * @param <C> The type of connection.
  * @see RoundRobinLoadBalancers
+ * @deprecated use {@link LoadBalancerBuilder} interfaces instead.
  */
+// FIXME: 0.43 - remove deprecated interface
+@Deprecated
 public interface RoundRobinLoadBalancerBuilder<ResolvedAddress, C extends LoadBalancedConnection> {
 
     /**

servicetalk-loadbalancer/src/main/java/io/servicetalk/loadbalancer/RoundRobinLoadBalancerBuilderProvider.java

@@ -19,8 +19,10 @@
 
 /**
  * Provider for {@link RoundRobinLoadBalancerBuilder} that can be registered using {@link java.util.ServiceLoader}.
+ * @deprecated use the {@link LoadBalancerBuilder} implementations along with {@link LoadBalancerBuilderProvider}
  */
-public interface RoundRobinLoadBalancerBuilderProvider {
+@Deprecated
+public interface RoundRobinLoadBalancerBuilderProvider { // FIXME: 0.43 - remove deprecated interface
 
     /**
      * Returns a {@link RoundRobinLoadBalancerBuilder} based on the pre-initialized

servicetalk-loadbalancer/src/main/java/io/servicetalk/loadbalancer/RoundRobinLoadBalancerFactory.java

@@ -48,10 +48,10 @@
  *
  * @param <ResolvedAddress> The resolved address type.
  * @param <C> The type of connection.
- * @deprecated this class will be made package-private in the future, use {@link RoundRobinLoadBalancers} to create
+ * @deprecated use {@link LoadBalancers} to create {@link LoadBalancerFactory} instances.
  * {@link RoundRobinLoadBalancerBuilder}.
  */
-@Deprecated // FIXME: 0.43 - make package private
+@Deprecated // FIXME: 0.43 - remove in favor of DefaultLoadBalancer types.
 public final class RoundRobinLoadBalancerFactory<ResolvedAddress, C extends LoadBalancedConnection>
         implements LoadBalancerFactory<ResolvedAddress, C> {
 
@@ -167,10 +167,9 @@ private <T extends C> LoadBalancer<T> buildDefaultLoadBalancerFactory(
      *
      * @param <ResolvedAddress> The resolved address type.
      * @param <C> The type of connection.
-     * @deprecated this class will be made package-private in the future, rely on the
-     * {@link RoundRobinLoadBalancerBuilder} instead.
+     * @deprecated rely on the {@link LoadBalancers#builder(String)} instead.
      */
-    @Deprecated // FIXME: 0.43 - make package private
+    @Deprecated // FIXME: 0.43 - Remove in favor of the DefaultLoadBalancer types
     public static final class Builder<ResolvedAddress, C extends LoadBalancedConnection>
             implements RoundRobinLoadBalancerBuilder<ResolvedAddress, C> {
         private final String id;
@@ -186,9 +185,9 @@ public static final class Builder<ResolvedAddress, C extends LoadBalancedConnect
         /**
          * Creates a new instance with default settings.
          *
-         * @deprecated use {@link RoundRobinLoadBalancers#builder(String)} instead.
+         * @deprecated use {@link LoadBalancers#builder(String)} instead.
          */
-        @Deprecated // FIXME: 0.43 - remove deprecated constructor
+        @Deprecated
         public Builder() {
             this("undefined");
         }

servicetalk-loadbalancer/src/main/java/io/servicetalk/loadbalancer/RoundRobinLoadBalancers.java

@@ -26,8 +26,10 @@
 
 /**
  * A factory to create {@link RoundRobinLoadBalancer RoundRobinLoadBalancers}.
+ * @deprecated use {@link LoadBalancers} instead.
  */
-public final class RoundRobinLoadBalancers {
+@Deprecated
+public final class RoundRobinLoadBalancers { // FIXME: 0.43 - remove deprecated class
     private static final Logger LOGGER = LoggerFactory.getLogger(RoundRobinLoadBalancers.class);
 
     private static final List<RoundRobinLoadBalancerBuilderProvider> PROVIDERS;
@@ -59,8 +61,10 @@ RoundRobinLoadBalancerBuilder<ResolvedAddress, C> applyProviders(
      * @param <ResolvedAddress> The resolved address type.
      * @param <C> The type of connection.
      * @return a new {@link RoundRobinLoadBalancerBuilder}.
+     * @deprecated use {#{@link LoadBalancers}} constructors instead.
      */
     @SuppressWarnings("deprecation")
+    @Deprecated
     public static <ResolvedAddress, C extends LoadBalancedConnection> RoundRobinLoadBalancerBuilder<ResolvedAddress, C>
     builder(final String id) {
         return applyProviders(id, new RoundRobinLoadBalancerFactory.Builder<>(id));