Require at least Java 11

.github/workflows/publish-documentation.yml

@@ -11,7 +11,7 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v4
         with:
-          distribution: 'zulu'
+          distribution: 'temurin'
           java-version: '21'
           cache: 'maven'
       - name: Publish Documentation

.github/workflows/publish-snapshot.yml

@@ -11,7 +11,7 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v4
         with:
-          distribution: 'zulu'
+          distribution: 'temurin'
           java-version: '21'
           cache: 'maven'
           server-id: ossrh

.github/workflows/release.yml

@@ -15,7 +15,7 @@ jobs:
         uses: actions/setup-java@v4
         with:
           distribution: 'temurin'
-          java-version: '8'
+          java-version: '11'
           cache: 'maven'
           server-id: ${{ env.maven_server_id }}
           server-username: MAVEN_USERNAME

.github/workflows/sanity-check.yml

@@ -23,8 +23,8 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v4
         with:
-          distribution: 'zulu'
-          java-version: '21'
+          distribution: 'temurin'
+          java-version: '11'
           cache: 'maven'
       - name: Start broker
         run: ci/start-broker.sh

.github/workflows/test-pr.yml

@@ -19,7 +19,7 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v4
         with:
-          distribution: 'zulu'
+          distribution: 'temurin'
           java-version: '21'
           cache: 'maven'
       - name: Start broker

.github/workflows/test-rabbitmq-alphas.yml

@@ -25,7 +25,7 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v4
         with:
-          distribution: 'zulu'
+          distribution: 'temurin'
           java-version: '21'
           cache: 'maven'
       - name: Start broker

.github/workflows/test-supported-java-versions.yml

@@ -11,7 +11,7 @@ jobs:
     strategy:
       matrix:
         distribution: [ 'temurin' ]
-        version: [ '8', '11', '17', '21', '23', '24-ea' ]
+        version: [ '11', '17', '21', '23', '24-ea' ]
         include:
           - distribution: 'semeru'
             version: '17'

.github/workflows/test.yml

@@ -23,7 +23,7 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v4
         with:
-          distribution: 'zulu'
+          distribution: 'temurin'
           java-version: '21'
           cache: 'maven'
           server-id: ossrh

README.adoc

@@ -31,7 +31,7 @@ See the https://www.rabbitmq.com/client-libraries/java-versions[RabbitMQ Java li
 
 === Pre-requisites
 
-This library requires at least Java 8, but Java 11 or more is recommended.
+This library requires at least Java 11, but Java 21 or more is recommended.
 
 === Dependencies
 
@@ -66,7 +66,7 @@ Breaking changes between releases can happen but will be kept to a minimum.
 
 == Build Instructions
 
-You need JDK 8 or later installed.
+You need JDK 11 or later installed.
 
 To build the JAR file:
 

pom.xml

@@ -348,8 +348,7 @@
         <artifactId>maven-compiler-plugin</artifactId>
         <version>${maven.compiler.plugin.version}</version>
         <configuration>
-          <source>1.8</source>
-          <target>1.8</target>
+          <release>11</release>
           <compilerArgs>
             <arg>-Xlint:deprecation</arg>
             <arg>-Xlint:unchecked</arg>
@@ -678,16 +677,6 @@
         </repository>
       </distributionManagement>
     </profile>
-    <profile>
-      <id>mockito-4-on-java-8</id>
-      <activation>
-        <jdk>1.8</jdk>
-      </activation>
-      <properties>
-        <mockito.version>4.11.0</mockito.version>
-        <test-arguments>-Xshare:off</test-arguments>
-      </properties>
-    </profile>
     <profile>
       <id>jvm-test-arguments-below-java-21</id>
       <activation>
@@ -707,31 +696,6 @@
       </properties>
     </profile>
 
-    <profile>
-      <!-- this avoids a compiler warning on Java 9+ -->
-      <!-- the compiler setting is not available on Java 8 -->
-      <id>use-release-compiler-argument-on-java-9-or-more</id>
-      <activation>
-        <jdk>[9,)</jdk>
-      </activation>
-      <build>
-        <plugins>
-          <plugin>
-            <artifactId>maven-compiler-plugin</artifactId>
-            <version>${maven.compiler.plugin.version}</version>
-            <configuration>
-              <source>1.8</source>
-              <target>1.8</target>
-              <release>8</release>
-              <compilerArgs>
-                <arg>-Xlint:deprecation</arg>
-                <arg>-Xlint:unchecked</arg>
-              </compilerArgs>
-            </configuration>
-          </plugin>
-        </plugins>
-      </build>
-    </profile>
 
   </profiles>
 

src/docs/asciidoc/building.adoc

@@ -1,6 +1,6 @@
 == Building the Client
 
-You need JDK 1.8 or more installed.
+You need JDK 11 or more installed.
 
 To build the JAR file:
 

src/docs/asciidoc/index.adoc

@@ -11,7 +11,7 @@ the https://rabbitmq.com/stream.html[RabbitMQ Stream Plugin].
 It allows creating and deleting streams, as well as publishing to and consuming from
 these streams. Learn more in the <<overview.adoc#stream-client-overview,client overview>>.
 
-This library requires at least Java 8, but Java 11 or more is recommended.
+This library requires at least Java 11, but Java 21 or more is recommended.
 
 https://github.com/rabbitmq/rabbitmq-stream-perf-test[Stream PerfTest] is a performance testing tool based on this client library.
 

src/docs/asciidoc/overview.adoc

@@ -107,4 +107,4 @@ _These SPI are susceptible to change, but this should have no impact on most app
 
 == Pre-requisites
 
-This library requires at least Java 8, but Java 11 or more is recommended (CRC calculation uses methods available as of Java 9).
+This library requires at least Java 11, but Java 21 or more is recommended.

src/main/java/com/rabbitmq/stream/ByteCapacity.java

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2023 Broadcom. All Rights Reserved.
+// Copyright (c) 2020-2024 Broadcom. All Rights Reserved.
 // The term "Broadcom" refers to Broadcom Inc. and/or its subsidiaries.
 //
 // This software, the RabbitMQ Stream Java client library, is dual-licensed under the
@@ -14,8 +14,6 @@
 // [email protected].
 package com.rabbitmq.stream;
 
-import java.util.Collections;
-import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
 import java.util.function.BiFunction;
@@ -40,15 +38,11 @@ public class ByteCapacity implements Comparable<ByteCapacity> {
   private static final String UNIT_TB = "tb";
 
   private static final Map<String, BiFunction<Long, String, ByteCapacity>> CONSTRUCTORS =
-      Collections.unmodifiableMap(
-          new HashMap<String, BiFunction<Long, String, ByteCapacity>>() {
-            {
-              put(UNIT_KB, (size, input) -> ByteCapacity.kB(size, input));
-              put(UNIT_MB, (size, input) -> ByteCapacity.MB(size, input));
-              put(UNIT_GB, (size, input) -> ByteCapacity.GB(size, input));
-              put(UNIT_TB, (size, input) -> ByteCapacity.TB(size, input));
-            }
-          });
+      Map.of(
+          UNIT_KB, ByteCapacity::kB,
+          UNIT_MB, ByteCapacity::MB,
+          UNIT_GB, ByteCapacity::GB,
+          UNIT_TB, ByteCapacity::TB);
 
   private final long bytes;
   private final String input;

src/main/java/com/rabbitmq/stream/impl/Client.java

@@ -442,7 +442,7 @@ public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise)
 
   private static Map<String, String> clientProperties(Map<String, String> fromParameters) {
     fromParameters = fromParameters == null ? Collections.emptyMap() : fromParameters;
-    Map<String, String> clientProperties = new HashMap<>(fromParameters);
+    Map<String, String> clientProperties = new LinkedHashMap<>(fromParameters);
     clientProperties.putAll(ClientProperties.DEFAULT_CLIENT_PROPERTIES);
     return Collections.unmodifiableMap(clientProperties);
   }
@@ -506,21 +506,22 @@ void authenticate(CredentialsProvider credentialsProvider) {
       } else if (saslAuthenticateResponse.isChallenge()) {
         challenge = saslAuthenticateResponse.challenge;
       } else if (saslAuthenticateResponse.isAuthenticationFailure()) {
-        String message =
-            "Unexpected response code during authentication: "
-                + formatConstant(saslAuthenticateResponse.getResponseCode());
+        StringBuilder message =
+            new StringBuilder(
+                "Unexpected response code during authentication: "
+                    + formatConstant(saslAuthenticateResponse.getResponseCode()));
         if (saslAuthenticateResponse.getResponseCode()
             == RESPONSE_CODE_AUTHENTICATION_FAILURE_LOOPBACK) {
-          message +=
-              ". The user is not authorized to connect from a remote host. "
-                  + "If the broker is running locally, make sure the '"
-                  + this.host
-                  + "' hostname is resolved to "
-                  + "the loopback interface (localhost, 127.0.0.1, ::1). "
-                  + "See https://www.rabbitmq.com/access-control.html#loopback-users.";
+          message
+              .append(". The user is not authorized to connect from a remote host. ")
+              .append("If the broker is running locally, make sure the '")
+              .append(this.host)
+              .append("' hostname is resolved to ")
+              .append("the loopback interface (localhost, 127.0.0.1, ::1). ")
+              .append("See https://www.rabbitmq.com/access-control.html#loopback-users.");
         }
         throw new AuthenticationFailureException(
-            message, saslAuthenticateResponse.getResponseCode());
+            message.toString(), saslAuthenticateResponse.getResponseCode());
       } else {
         throw new StreamException(
             "Unexpected response code during authentication: "
@@ -2223,7 +2224,7 @@ static class StreamStatsResponse extends Response {
 
     StreamStatsResponse(short responseCode, Map<String, Long> info) {
       super(responseCode);
-      this.info = Collections.unmodifiableMap(new HashMap<>(info));
+      this.info = Map.copyOf(info);
     }
 
     public Map<String, Long> getInfo() {
@@ -2248,7 +2249,7 @@ public StreamMetadata(String stream, short responseCode, Broker leader, List<Bro
       this.replicas =
           (replicas == null || replicas.isEmpty())
               ? Collections.emptyList()
-              : Collections.unmodifiableList(replicas);
+              : List.copyOf(replicas);
     }
 
     public short getResponseCode() {
@@ -2263,8 +2264,9 @@ public Broker getLeader() {
       return leader;
     }
 
+    @SuppressFBWarnings("EI_EXPOSE_REP")
     public List<Broker> getReplicas() {
-      return this.replicas.isEmpty() ? Collections.emptyList() : new ArrayList<>(this.replicas);
+      return this.replicas;
     }
 
     boolean hasReplicas() {
@@ -2561,7 +2563,7 @@ int port() {
     }
 
     Map<String, String> clientProperties() {
-      return Collections.unmodifiableMap(this.clientProperties);
+      return Map.copyOf(this.clientProperties);
     }
 
     Codec codec() {

src/main/java/com/rabbitmq/stream/impl/ClientProperties.java

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2023 Broadcom. All Rights Reserved.
+// Copyright (c) 2020-2024 Broadcom. All Rights Reserved.
 // The term "Broadcom" refers to Broadcom Inc. and/or its subsidiaries.
 //
 // This software, the RabbitMQ Stream Java client library, is dual-licensed under the
@@ -15,10 +15,7 @@
 package com.rabbitmq.stream.impl;
 
 import java.io.InputStream;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Properties;
+import java.util.*;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -40,7 +37,7 @@ public final class ClientProperties {
 
   public static final Map<String, String> DEFAULT_CLIENT_PROPERTIES =
       Collections.unmodifiableMap(
-          new HashMap<String, String>() {
+          new LinkedHashMap<>() {
             {
               put("product", "RabbitMQ Stream");
               put("version", ClientProperties.VERSION);