Downgrade codegen and remaining subprojects to JDK 17

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
     name: Java ${{ matrix.java }} ${{ matrix.os }}
     strategy:
       matrix:
-        java: [21]
+        java: [17]
         os: [macos-latest, ubuntu-latest, windows-latest]
 
     steps:

buildSrc/src/main/groovy/smithy-java.java-conventions.gradle

@@ -10,14 +10,10 @@ plugins {
 
 java {
     toolchain {
-        languageVersion = JavaLanguageVersion.of(21)
+        languageVersion = JavaLanguageVersion.of(17)
     }
 }
 
-tasks.compileJava {
-    options.release = 17
-}
-
 /*
  * Common test configuration
  * ===============================

codegen/build.gradle

@@ -4,10 +4,6 @@ plugins {
 
 description = "This module provides the codegen functionality for Smithy java"
 
-tasks.compileJava {
-    options.release = 21
-}
-
 ext {
     displayName = "Smithy :: Java :: Codegen"
     moduleName = "software.amazon.smithy.smithy-java.codegen"

codegen/src/main/java/software/amazon/smithy/java/codegen/JavaSymbolProvider.java

@@ -9,12 +9,14 @@
 
 import java.time.Instant;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
-import java.util.SequencedSet;
+import java.util.Set;
+import java.util.SortedSet;
 import software.amazon.smithy.codegen.core.CodegenException;
 import software.amazon.smithy.codegen.core.Symbol;
 import software.amazon.smithy.codegen.core.SymbolProvider;
@@ -48,6 +50,7 @@
 import software.amazon.smithy.model.shapes.UnionShape;
 import software.amazon.smithy.model.traits.StreamingTrait;
 import software.amazon.smithy.model.traits.UniqueItemsTrait;
+import software.amazon.smithy.utils.BuilderRef;
 import software.amazon.smithy.utils.CaseUtils;
 
 /**
@@ -112,11 +115,11 @@ public Symbol booleanShape(BooleanShape booleanShape) {
     public Symbol listShape(ListShape listShape) {
         // Lists with unique Items are treated as Sequenced Sets
         if (listShape.hasTrait(UniqueItemsTrait.class)) {
-            return SymbolUtils.fromClass(SequencedSet.class)
+            return SymbolUtils.fromClass(Set.class)
                 .toBuilder()
-                .putProperty(SymbolProperties.COLLECTION_COPY_METHOD, "unmodifiableSequencedSet")
+                .putProperty(SymbolProperties.COLLECTION_COPY_METHOD, "unmodifiableSet")
                 .putProperty(SymbolProperties.COLLECTION_IMPLEMENTATION_CLASS, LinkedHashSet.class)
-                .putProperty(SymbolProperties.COLLECTION_EMPTY_METHOD, "emptySortedSet()")
+                .putProperty(SymbolProperties.COLLECTION_EMPTY_METHOD, "emptySet()")
                 .addReference(listShape.getMember().accept(this))
                 .build();
         }

codegen/src/main/java/software/amazon/smithy/java/codegen/generators/TraitInitializerGenerator.java

@@ -50,17 +50,22 @@ public void run() {
             var iter = traitsToAdd.iterator();
             while (iter.hasNext()) {
                 var traitId = iter.next();
-                switch (shape.getAllTraits().get(traitId)) {
-                    case AnnotationTrait a -> writer.writeInline("new $T()", a.getClass());
-                    case StringTrait st -> writer.writeInline("new $T($S)", st.getClass(), st.getValue());
-                    case StringListTrait slt -> writer.writeInline(
-                        "new $T($S, $T.NONE)",
-                        slt.getClass(),
-                        slt.getValues(),
-                        SourceLocation.class
+                Trait trait = shape.getAllTraits().get(traitId);
+                if (trait instanceof AnnotationTrait) {
+                    writer.writeInline("new $T()", trait.getClass());
+                } else if (trait instanceof StringTrait) {
+                    writer.writeInline("new $T($S)", trait.getClass(), ((StringTrait) trait).getValue());
+                } else if (trait instanceof StringListTrait) {
+                    writer.writeInline(
+                            "new $T($S, $T.NONE)",
+                            trait.getClass(),
+                            ((StringListTrait) trait).getValues(),
+                            SourceLocation.class
                     );
-                    case Trait t -> traitFactoryInitializer(writer, t);
+                } else {
+                    traitFactoryInitializer(writer, trait);
                 }
+
                 if (iter.hasNext()) {
                     writer.writeInline(",").newLine();
                 }

codegen/src/main/java/software/amazon/smithy/java/codegen/integrations/javadoc/JavadocInjectorInterceptor.java

@@ -37,11 +37,14 @@ public boolean isIntercepted(CodeSection section) {
 
     @Override
     public void prepend(JavaWriter writer, CodeSection section) {
-        Shape shape = switch (section) {
-            case ClassSection s -> s.shape();
-            case GetterSection s -> s.memberShape();
-            default -> throw new IllegalArgumentException("Javadocs cannot be injected for section: " + section);
-        };
+        Shape shape;
+        if (section instanceof ClassSection) {
+            shape = ((ClassSection) section).shape();
+        } else if (section instanceof GetterSection) {
+            shape = ((GetterSection) section).memberShape();
+        } else {
+            throw new IllegalArgumentException("Javadocs cannot be injected for section: " + section);
+        }
 
         writer.injectSection(new JavadocSection(shape));
 

codegen/src/main/java/software/amazon/smithy/java/codegen/writer/JavaWriter.java

@@ -143,15 +143,19 @@ public JavaWriter apply(String filename, String namespace) {
     private final class JavaTypeFormatter implements BiFunction<Object, String, String> {
         @Override
         public String apply(Object type, String indent) {
-            Symbol typeSymbol = switch (type) {
-                case Symbol s -> s;
-                case Class<?> c -> SymbolUtils.fromClass(c);
-                case SymbolReference r -> r.getSymbol();
-                default -> throw new IllegalArgumentException(
-                    "Invalid type provided for $T. Expected a Symbol or Class"
-                        + " but found: `" + type + "`."
-                );
-            };
+
+            Symbol typeSymbol;
+            if (type instanceof Symbol) {
+                typeSymbol = (Symbol) type;
+            } else if (type instanceof Class<?>) {
+                typeSymbol = SymbolUtils.fromClass((Class<?>) type);
+            } else if (type instanceof SymbolReference) {
+                typeSymbol = ((SymbolReference) type).getSymbol();
+            } else {
+                throw new IllegalArgumentException(
+                        "Invalid type provided for $T. Expected a Symbol or Class"
+                                + " but found: `" + type + "`.");
+            }
 
             if (typeSymbol.getReferences().isEmpty()) {
                 return getPlaceholder(typeSymbol);
@@ -187,15 +191,18 @@ private final class BoxedTypeFormatter implements BiFunction<Object, String, Str
 
         @Override
         public String apply(Object type, String indent) {
-            Symbol typeSymbol = switch (type) {
-                case Symbol s -> s;
-                case Class<?> c -> SymbolUtils.fromClass(c);
-                case SymbolReference r -> r.getSymbol();
-                default -> throw new IllegalArgumentException(
-                    "Invalid type provided for $B. Expected a Symbol or Class"
-                        + " but found: `" + type + "`."
-                );
-            };
+            Symbol typeSymbol;
+            if (type instanceof Symbol) {
+                typeSymbol = (Symbol) type;
+            } else if (type instanceof Class<?>) {
+                typeSymbol = SymbolUtils.fromClass((Class<?>) type);
+            } else if (type instanceof SymbolReference) {
+                typeSymbol = ((SymbolReference) type).getSymbol();
+            } else {
+                throw new IllegalArgumentException(
+                        "Invalid type provided for $B. Expected a Symbol or Class"
+                                + " but found: `" + type + "`.");
+            }
 
             if (typeSymbol.getProperty(SymbolProperties.BOXED_TYPE).isPresent()) {
                 typeSymbol = typeSymbol.expectProperty(SymbolProperties.BOXED_TYPE, Symbol.class);

config/spotless/formatting.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
-<profiles version="21">
-    <profile kind="CodeFormatterProfile" name="Smithy Formatting" version="21">
+<profiles version="17">
+    <profile kind="CodeFormatterProfile" name="Smithy Formatting" version="17">
         <setting id="org.eclipse.jdt.core.formatter.insert_new_line_after_type_annotation" value="do not insert"/>
         <setting id="org.eclipse.jdt.core.formatter.insert_new_line_in_empty_type_declaration" value="do not insert"/>
         <setting id="org.eclipse.jdt.core.formatter.insert_new_line_in_empty_method_body" value="do not insert"/>

examples/restjson-example/build.gradle

@@ -3,10 +3,6 @@ plugins {
     alias(libs.plugins.jmh)
 }
 
-tasks.compileJava {
-    options.release = 21
-}
-
 dependencies {
     api(project(":client-aws-rest-json1"))
     api(libs.smithy.aws.traits)