revert back to Java 8

Author: sigpwned

hermes-aws-lambda/src/main/java/com/sigpwned/hermes/aws/lambda/sns/SnsConsumerLambdaFunctionBase.java

@@ -23,6 +23,7 @@
 import java.math.BigDecimal;
 import java.util.List;
 import java.util.Optional;
+import java.util.stream.Stream;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import com.amazonaws.services.lambda.runtime.Context;
@@ -56,15 +57,19 @@ protected static Message toMessage(SNSRecord m) {
     String id = m.getSNS().getMessageId();
 
     MessageHeaders headers = MessageHeaders.of(m.getSNS().getMessageAttributes().entrySet().stream()
-        .flatMap(e -> toMessageAttributeValue(e.getValue())
-            .map(v -> MessageHeader.of(e.getKey(), v)).stream())
+        .flatMap(e -> stream(
+            toMessageAttributeValue(e.getValue()).map(v -> MessageHeader.of(e.getKey(), v))))
         .collect(toList()));
 
     String body = m.getSNS().getMessage();
 
     return Message.of(id, headers, body);
   }
 
+  private static <T> Stream<T> stream(Optional<T> o) {
+    return o.isPresent() ? Stream.of(o.get()) : Stream.empty();
+  }
+
   protected static Optional<MessageHeaderValue> toMessageAttributeValue(MessageAttribute a) {
     MessageHeaderValue result;
 

hermes-aws-lambda/src/main/java/com/sigpwned/hermes/aws/lambda/sqs/SqsConsumerLambdaFunctionBase.java

@@ -23,6 +23,7 @@
 import java.math.BigDecimal;
 import java.util.List;
 import java.util.Optional;
+import java.util.stream.Stream;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import com.amazonaws.services.lambda.runtime.Context;
@@ -56,15 +57,19 @@ protected static Message toMessage(SQSMessage m) {
     String id = m.getMessageId();
 
     MessageHeaders headers = MessageHeaders.of(m.getMessageAttributes().entrySet().stream()
-        .flatMap(e -> toMessageAttributeValue(e.getValue())
-            .map(v -> MessageHeader.of(e.getKey(), v)).stream())
+        .flatMap(e -> stream(
+            toMessageAttributeValue(e.getValue()).map(v -> MessageHeader.of(e.getKey(), v))))
         .collect(toList()));
 
     String body = m.getBody();
 
     return Message.of(id, headers, body);
   }
 
+  private static <T> Stream<T> stream(Optional<T> o) {
+    return o.isPresent() ? Stream.of(o.get()) : Stream.empty();
+  }
+
   protected static Optional<MessageHeaderValue> toMessageAttributeValue(MessageAttribute a) {
     MessageHeaderValue result;
 

hermes-aws-sqs/src/main/java/com/sigpwned/hermes/aws/sqs/messageconsumer/SqsMessageConsumer.java

@@ -19,9 +19,9 @@
  */
 package com.sigpwned.hermes.aws.sqs.messageconsumer;
 
+import static java.util.Collections.emptyList;
 import static java.util.stream.Collectors.toList;
 import java.math.BigDecimal;
-import java.util.List;
 import java.util.stream.Stream;
 import com.sigpwned.hermes.aws.sqs.SqsDestination;
 import com.sigpwned.hermes.aws.sqs.messageconsumer.batch.DefaultSqsMessageBatch;
@@ -87,7 +87,7 @@ public SqsMessageBatch receive(int maxNumberOfMessages, int waitTimeSeconds,
                         .collect(toList())),
                     m.body(), m.receiptHandle()))
                 .collect(toList())
-            : List.of());
+            : emptyList());
   }
 
   private static MessageHeader toMessageHeader(MessageSystemAttributeName k, String v) {

hermes-aws-sqs/src/main/java/com/sigpwned/hermes/aws/sqs/messageconsumer/batch/CombinedSqsMessageBatch.java

@@ -19,8 +19,8 @@
  */
 package com.sigpwned.hermes.aws.sqs.messageconsumer.batch;
 
+import static java.util.Collections.unmodifiableList;
 import static java.util.stream.Collectors.toList;
-import static java.util.stream.Collectors.toUnmodifiableList;
 import java.util.Iterator;
 import java.util.List;
 import java.util.stream.Stream;
@@ -42,8 +42,8 @@ public CombinedSqsMessageBatch(List<SqsMessageBatch> batches) {
       throw new IllegalArgumentException("multiple destinations " + destinations);
     this.batches = batches;
     this.destination = destinations.get(0);
-    this.messages =
-        getBatches().stream().flatMap(b -> b.getMessages().stream()).collect(toUnmodifiableList());
+    this.messages = unmodifiableList(
+        getBatches().stream().flatMap(b -> b.getMessages().stream()).collect(toList()));
   }
 
   @Override

hermes-aws-sqs/src/main/java/com/sigpwned/hermes/aws/sqs/messageloop/plan/BackoffSqsReceivePlanner.java

@@ -19,10 +19,10 @@
  */
 package com.sigpwned.hermes.aws.sqs.messageloop.plan;
 
+import static java.util.Arrays.asList;
 import static java.util.Objects.requireNonNull;
 import java.time.Duration;
 import java.util.Collections;
-import java.util.List;
 import com.sigpwned.hermes.aws.sqs.messageconsumer.SqsMessageBatch;
 import com.sigpwned.hermes.aws.sqs.messageloop.SqsMessageLoopBody;
 import com.sigpwned.hermes.aws.sqs.messageloop.SqsReceivePlan;
@@ -66,7 +66,7 @@ public SqsReceivePlan plan() throws InterruptedException {
 
     if (consecutiveErrors > 0)
       Thread.sleep(
-          Collections.min(List.of(backoff(consecutiveErrors), getMaximumBackoff())).toMillis());
+          Collections.min(asList(backoff(consecutiveErrors), getMaximumBackoff())).toMillis());
 
     return getDelegate().plan();
   }

hermes-aws-sqs/src/main/java/com/sigpwned/hermes/aws/sqs/messageloop/plan/ThrottlingSqsReceivePlanner.java

@@ -23,6 +23,7 @@
 import java.time.Duration;
 import java.time.LocalDate;
 import java.time.LocalTime;
+import java.time.Month;
 import java.time.OffsetDateTime;
 import java.time.ZoneOffset;
 import com.sigpwned.hermes.aws.sqs.messageloop.SqsReceivePlan;
@@ -43,7 +44,8 @@ public ThrottlingSqsReceivePlanner(SqsReceivePlanner delegate, Duration minimumD
       throw new IllegalArgumentException("minimumDuration must not be negative");
     this.delegate = requireNonNull(delegate);
     this.minimumDuration = requireNonNull(minimumDuration);
-    this.last = OffsetDateTime.of(LocalDate.EPOCH, LocalTime.MIN, ZoneOffset.UTC);
+    this.last =
+        OffsetDateTime.of(LocalDate.of(1970, Month.JANUARY, 1), LocalTime.MIN, ZoneOffset.UTC);
   }
 
   @Override

hermes-core/src/main/java/com/sigpwned/hermes/core/messageproducer/BatchingMessageProducer.java

@@ -20,6 +20,7 @@
 package com.sigpwned.hermes.core.messageproducer;
 
 import static java.lang.String.format;
+import static java.util.Collections.emptyList;
 import static java.util.stream.Collectors.toCollection;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -47,7 +48,7 @@ public BatchingMessageProducer(MessageProducer delegate, int maxPayloadSize) {
   public void send(List<MessageContent> messages) {
     List<MessageContent> combined;
     if (messages.isEmpty()) {
-      combined = List.of();
+      combined = emptyList();
     } else {
       combined = combine(messages);
     }

hermes-core/src/main/java/com/sigpwned/hermes/core/messageproducer/GroupingMessageProducer.java

@@ -20,6 +20,7 @@
 package com.sigpwned.hermes.core.messageproducer;
 
 import static java.lang.String.format;
+import static java.util.Collections.emptyList;
 import static java.util.stream.Collectors.toCollection;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -49,7 +50,7 @@ public GroupingMessageProducer(MessageProducer delegate, int maxPayloadSize, int
   public void send(List<MessageContent> messages) {
     List<List<MessageContent>> grouped;
     if (messages.isEmpty()) {
-      grouped = List.of();
+      grouped = emptyList();
     } else {
       grouped = group(messages);
     }

hermes-core/src/main/java/com/sigpwned/hermes/core/model/MessageHeaders.java

@@ -19,6 +19,7 @@
  */
 package com.sigpwned.hermes.core.model;
 
+import static java.util.Collections.emptyList;
 import static java.util.Collections.unmodifiableList;
 import java.util.Iterator;
 import java.util.List;
@@ -27,7 +28,7 @@
 import java.util.stream.Stream;
 
 public class MessageHeaders implements Iterable<MessageHeader> {
-  public static final MessageHeaders EMPTY = of(List.of());
+  public static final MessageHeaders EMPTY = of(emptyList());
 
   public static MessageHeaders of() {
     return EMPTY;

pom.xml

@@ -6,7 +6,7 @@
     <version>0.0.0-b4-SNAPSHOT</version>
     <name>hermes</name>
     <inceptionYear>2022</inceptionYear>
-    <description>Divine Messaging in the Cloud for Java 11+</description>
+    <description>Divine Messaging in the Cloud for Java 8+</description>
     <url>https://github.com/sigpwned/hermes</url>
     <packaging>pom</packaging>
 
@@ -77,9 +77,9 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.10.1</version>
                 <configuration>
-                    <source>11</source>
-                    <target>11</target>
-                    <release>11</release>
+                    <source>8</source>
+                    <target>8</target>
+                    <release>8</release>
                 </configuration>
             </plugin>