Clarify "target" parameter in channel factory APIs

Clarifies the javadocs with the allowed values for the "target" input
parameter on the `GrpcChannelFactory` create/supports APIs.

Also clarifies the javadocs and renames the "authority" input parameter
on `GrpcChannelBuilderCustomizer#customize` to "target".

Signed-off-by: onobc <chris.bono@gmail.com>

Author: onobc

spring-grpc-client-spring-boot-autoconfigure/src/main/java/org/springframework/boot/grpc/client/autoconfigure/ClientPropertiesChannelBuilderCustomizer.java

@@ -48,11 +48,11 @@ class ClientPropertiesChannelBuilderCustomizer<T extends ManagedChannelBuilder<T
 	}
 
 	@Override
-	public void customize(String authority, T builder) {
-		ChannelConfig channel = this.properties.getChannel(authority);
+	public void customize(String target, T builder) {
+		ChannelConfig channel = this.properties.getChannel(target);
 		PropertyMapper mapper = PropertyMapper.get();
 		mapper.from(channel.getUserAgent()).to(builder::userAgent);
-		if (targetAllowsLoadBalancer(authority)) {
+		if (targetAllowsLoadBalancer(target)) {
 			mapper.from(channel.getDefaultLoadBalancingPolicy()).to(builder::defaultLoadBalancingPolicy);
 		}
 		mapper.from(channel.getMaxInboundMessageSize()).asInt(DataSize::toBytes).to(builder::maxInboundMessageSize);

spring-grpc-core/src/main/java/org/springframework/grpc/client/DefaultGrpcChannelFactory.java

@@ -81,7 +81,7 @@ public DefaultGrpcChannelFactory(List<GrpcChannelBuilderCustomizer<T>> globalCus
 
 	/**
 	 * {@inheritDoc}
-	 * @param target the target string as described in method javadocs
+	 * @param target the target string
 	 * @return true unless the target begins with 'in-process:'
 	 */
 	@Override

spring-grpc-core/src/main/java/org/springframework/grpc/client/GrpcChannelBuilderCustomizer.java

@@ -18,11 +18,13 @@
 
 import java.util.function.Consumer;
 
+import io.grpc.ChannelCredentials;
+import io.grpc.Grpc;
 import io.grpc.ManagedChannelBuilder;
 
 /**
  * Callback interface that can be used to customize a {@link ManagedChannelBuilder} for a
- * specific authority.
+ * specific target.
  *
  * @param <T> type of builder
  * @author Dave Syer
@@ -33,16 +35,19 @@ public interface GrpcChannelBuilderCustomizer<T extends ManagedChannelBuilder<T>
 
 	/**
 	 * Callback to customize a {@link ManagedChannelBuilder channel builder} instance for
-	 * a specific target authority.
-	 * @param authority the target authority for the channel
+	 * a specific target string. The target can be either a valid nameresolver-compliant
+	 * URI or an authority string as described in
+	 * {@link Grpc#newChannelBuilder(String, ChannelCredentials)}, or the name of a
+	 * user-configured channel (e.g. 'my-channel').
+	 * @param target the target string
 	 * @param builder the builder to customize
 	 */
-	void customize(String authority, T builder);
+	void customize(String target, T builder);
 
 	default GrpcChannelBuilderCustomizer<T> then(GrpcChannelBuilderCustomizer<T> other) {
-		return (authority, builder) -> {
-			customize(authority, builder);
-			other.customize(authority, builder);
+		return (target, builder) -> {
+			customize(target, builder);
+			other.customize(target, builder);
 		};
 	}
 
@@ -58,8 +63,8 @@ static <T extends ManagedChannelBuilder<T>> GrpcChannelBuilderCustomizer<T> defa
 
 	static <T extends ManagedChannelBuilder<T>> GrpcChannelBuilderCustomizer<T> matching(String pattern,
 			Consumer<ManagedChannelBuilder<T>> consumer) {
-		return (authority, channel) -> {
-			if (pattern.matches(authority)) {
+		return (target, channel) -> {
+			if (pattern.matches(target)) {
 				consumer.accept(channel);
 			}
 		};

spring-grpc-core/src/main/java/org/springframework/grpc/client/GrpcChannelFactory.java

@@ -30,11 +30,12 @@
 public interface GrpcChannelFactory {
 
 	/**
-	 * Whether this factory supports the given target string. The target can be either a
-	 * valid nameresolver-compliant URI, an authority string as described in
-	 * {@link Grpc#newChannelBuilder(String, ChannelCredentials)}, or a named channel
-	 * which will use the address of a user-configured channel as the target to check.
-	 * @param target the target string as described in method javadocs
+	 * Whether this factory supports the given target string.
+	 * <p>
+	 * The target can be either a valid nameresolver-compliant URI or an authority string
+	 * as described in {@link Grpc#newChannelBuilder(String, ChannelCredentials)}, or the
+	 * name of a user-configured channel (e.g. 'my-channel').
+	 * @param target the target string
 	 * @return whether this factory supports the given target string
 	 */
 	boolean supports(String target);
@@ -49,14 +50,15 @@ default boolean supports(ClientInterceptor interceptor) {
 	}
 
 	/**
-	 * Creates a {@link ManagedChannel} for the given target string. The target can be
-	 * either a valid nameresolver-compliant URI, an authority string as described in
-	 * {@link Grpc#newChannelBuilder(String, ChannelCredentials)}, or a named channel
-	 * which will return a builder that is based on a user-configured channel.
+	 * Creates a {@link ManagedChannel} for the given target string.
+	 * <p>
+	 * The target can be either a valid nameresolver-compliant URI or an authority string
+	 * as described in {@link Grpc#newChannelBuilder(String, ChannelCredentials)}, or the
+	 * name of a user-configured channel (e.g. 'my-channel').
 	 * <p>
 	 * The returned channel is configured to use all globally registered
 	 * {@link ClientInterceptor interceptors}.
-	 * @param target the target string as described in method javadocs
+	 * @param target the target string
 	 * @return a channel for the given target
 	 */
 	default ManagedChannel createChannel(String target) {
@@ -65,9 +67,10 @@ default ManagedChannel createChannel(String target) {
 
 	/**
 	 * Creates a {@link ManagedChannel} for the given target string. The target can be
-	 * either a valid nameresolver-compliant URI, an authority string as described in
-	 * {@link Grpc#newChannelBuilder(String, ChannelCredentials)}, or a named channel
-	 * which will return a builder that is based on a user-configured channel.
+	 * <p>
+	 * The target can be either a valid nameresolver-compliant URI or an authority string
+	 * as described in {@link Grpc#newChannelBuilder(String, ChannelCredentials)}, or the
+	 * name of a user-configured channel (e.g. 'my-channel').
 	 * <p>
 	 * The returned channel is configured to use all globally registered
 	 * {@link ClientInterceptor interceptors} and any user-provided interceptor if

spring-grpc-core/src/main/java/org/springframework/grpc/client/InProcessGrpcChannelFactory.java

@@ -44,7 +44,7 @@ public InProcessGrpcChannelFactory(List<GrpcChannelBuilderCustomizer<InProcessCh
 
 	/**
 	 * {@inheritDoc}
-	 * @param target the target string as described in method javadocs
+	 * @param target the target string
 	 * @return true if the target begins with 'in-process:'
 	 */
 	@Override