Improve name conflicts resolving

codegen/codegen-core/src/main/java/software/amazon/smithy/java/codegen/CodegenUtils.java

@@ -338,6 +338,8 @@ public static String toUpperSnakeCase(String string) {
      */
     public static Symbol getInnerTypeEnumSymbol(Symbol symbol) {
         return symbol.toBuilder()
+                .namespace(symbol.getFullName(), ".")
+                .putProperty(SymbolProperties.IS_LOCALLY_DEFINED, true)
                 .name("Type")
                 .build();
     }

codegen/codegen-core/src/main/java/software/amazon/smithy/java/codegen/SymbolProperties.java

@@ -32,6 +32,11 @@ public final class SymbolProperties {
      */
     public static final Property<Boolean> IS_JAVA_ARRAY = Property.named("is-java-array");
 
+    /**
+     * Indicates if a symbol represents an inner class.
+     */
+    public static final Property<Boolean> IS_LOCALLY_DEFINED = Property.named("is-locally-defined");
+
     /**
      * Method on {@link java.util.Collection} to use to create an immutable copy of the collection type
      * a symbol represents.

codegen/codegen-core/src/main/java/software/amazon/smithy/java/codegen/generators/UnionGenerator.java

@@ -42,6 +42,8 @@ public void accept(GenerateUnionDirective<CodeGenerationContext, JavaCodegenSett
         }
         var shape = directive.shape();
         directive.context().writerDelegator().useShapeWriter(shape, writer -> {
+            var innerTypeEnumSymbol = CodegenUtils.getInnerTypeEnumSymbol(directive.symbol());
+            writer.addLocallyDefinedSymbol(innerTypeEnumSymbol);
             writer.pushState(new ClassSection(shape));
             var template = """
                     public abstract class ${shape:T} implements ${serializableStruct:T} {
@@ -97,7 +99,7 @@ public boolean equals(${object:T} other) {
                     }
                     """;
             writer.putContext("shape", directive.symbol());
-            writer.putContext("type", CodegenUtils.getInnerTypeEnumSymbol(directive.symbol()));
+            writer.putContext("type", innerTypeEnumSymbol);
             writer.putContext("serializableStruct", SerializableStruct.class);
             writer.putContext("shapeSerializer", ShapeSerializer.class);
             writer.putContext("schemaClass", Schema.class);

codegen/codegen-core/src/main/java/software/amazon/smithy/java/codegen/writer/JavaImportContainer.java

@@ -26,8 +26,10 @@ final class JavaImportContainer implements ImportContainer {
 
     @Override
     public void importSymbol(Symbol symbol, String s) {
-        // Do not import primitive types or java.lang standard library imports.
-        if (symbol.expectProperty(SymbolProperties.IS_PRIMITIVE) || symbol.getNamespace().startsWith("java.lang")) {
+        // Do not import primitive types, java.lang standard library imports or inner classes.
+        if (symbol.expectProperty(SymbolProperties.IS_PRIMITIVE)
+                || symbol.getNamespace().startsWith("java.lang")
+                || symbol.getProperty(SymbolProperties.IS_LOCALLY_DEFINED).isPresent()) {
             return;
         }
         Set<Symbol> duplicates = imports.computeIfAbsent(symbol.getName(), sn -> new HashSet<>());

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

@@ -5,6 +5,7 @@
 
 package software.amazon.smithy.java.codegen.writer;
 
+import java.util.HashSet;
 import java.util.Set;
 import java.util.function.BiFunction;
 import software.amazon.smithy.codegen.core.Symbol;
@@ -33,6 +34,7 @@ public final class JavaWriter extends DeferredSymbolWriter<JavaWriter, JavaImpor
     private final String packageNamespace;
     private final JavaCodegenSettings settings;
     private final String filename;
+    private final Set<String> locallyDefinedNames = new HashSet<>();
 
     public JavaWriter(JavaCodegenSettings settings, String packageNamespace, String filename) {
         super(new JavaImportContainer(packageNamespace));
@@ -87,28 +89,56 @@ public void newLine() {
     private void putNameContext() {
         // Add any implicit usages from classes in the same package
         var packageSymbols = settings.getGeneratedSymbolsPackage(packageNamespace);
-        packageSymbols.forEach(this::addToSymbolTable);
-        for (final Set<Symbol> duplicates : symbolTable.values()) {
+        Set<String> packageDefinedNames = new HashSet<>();
+        for (Symbol packageSymbol : packageSymbols) {
+            packageDefinedNames.add(packageSymbol.getName());
+        }
+        for (Set<Symbol> duplicates : symbolTable.values()) {
             // If the duplicates list has more than one entry
             // then duplicates are present, and we need to de-duplicate the names
             if (duplicates.size() > 1) {
                 duplicates.forEach(dupe -> putContext(dupe.getFullName(), deduplicate(dupe)));
             } else {
                 Symbol symbol = duplicates.iterator().next();
-                putContext(symbol.getFullName().replace("[]", "Array"), symbol.getName());
+                // Use fully qualified names for java.lang.* if there is duplicate names
+                // defined under the same package.
+                String symbolName = symbol.getName();
+                if (packageDefinedNames.contains(symbol.getName()) && symbol.getNamespace().equals("java.lang")) {
+                    symbolName = symbol.getFullName();
+                }
+                putContext(symbol.getFullName(), symbolName);
             }
         }
     }
 
     private String deduplicate(Symbol dupe) {
-        // If we are in the namespace of a Symbol, use its
-        // short name, otherwise use the full name
-        if (dupe.getNamespace().equals(packageNamespace)) {
+        if (useSimpleName(dupe)) {
             return dupe.getName();
         }
         return dupe.getFullName();
     }
 
+    private boolean useSimpleName(Symbol dupe) {
+        // Only locally defined symbols and those symbols with non-conflicting names
+        // under the same namespace can use short name.
+        if (locallyDefinedNames.contains(dupe.getName())) {
+            return dupe.getProperty(SymbolProperties.IS_LOCALLY_DEFINED).isPresent();
+        }
+        return dupe.getNamespace().equals(packageNamespace);
+    }
+
+    /**
+     * Records the local name defined within the current file, e.g., the name of an inner class.
+     * The writer will use this information to decide if it should use a fully qualified
+     * name when referencing types with the same name in its scope.
+     *
+     * @param symbol the symbol reserved in this file.
+     */
+    public void addLocallyDefinedSymbol(Symbol symbol) {
+        locallyDefinedNames.add(symbol.getName());
+        symbolTable.computeIfAbsent(symbol.getName(), k -> new HashSet<>()).add(symbol);
+    }
+
     /**
      * A factory class to create {@link JavaWriter}s.
      */

codegen/codegen-core/src/main/resources/software/amazon/smithy/java/codegen/reserved-words.txt

@@ -25,6 +25,7 @@ double
 else
 enum
 extends
+false
 final
 finally
 float
@@ -33,13 +34,13 @@ goto
 if
 implements
 import
-type
 instanceof
 int
 interface
 long
 native
 new
+null
 object
 package
 private
@@ -57,9 +58,7 @@ throw
 throws
 transient
 try
+true
 void
 volatile
 while
-true
-false
-null

codegen/plugins/types-codegen/src/test/resources/software/amazon/smithy/java/codegen/types/test-cases/naming-conflict/expected/BuilderShape.java

@@ -0,0 +1,114 @@
+
+package software.amazon.smithy.java.example.standalone.model;
+
+import java.util.Objects;
+import software.amazon.smithy.java.core.schema.Schema;
+import software.amazon.smithy.java.core.schema.SerializableStruct;
+import software.amazon.smithy.java.core.schema.ShapeBuilder;
+import software.amazon.smithy.java.core.serde.ShapeDeserializer;
+import software.amazon.smithy.java.core.serde.ShapeSerializer;
+import software.amazon.smithy.java.core.serde.ToStringSerializer;
+import software.amazon.smithy.model.shapes.ShapeId;
+import software.amazon.smithy.utils.SmithyGenerated;
+
+@SmithyGenerated
+public final class BuilderShape implements SerializableStruct {
+
+    public static final Schema $SCHEMA = Schemas.BUILDER;
+
+    public static final ShapeId $ID = $SCHEMA.id();
+
+    private BuilderShape(Builder builder) {
+    }
+
+    @Override
+    public String toString() {
+        return ToStringSerializer.serialize(this);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other == this) {
+            return true;
+        }
+        return other != null && getClass() == other.getClass();
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash();
+    }
+
+    @Override
+    public Schema schema() {
+        return $SCHEMA;
+    }
+
+    @Override
+    public void serializeMembers(ShapeSerializer serializer) {
+
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public <T> T getMemberValue(Schema member) {
+        throw new IllegalArgumentException("Attempted to get non-existent member: " + member.id());
+    }
+
+    /**
+     * Create a new builder containing all the current property values of this object.
+     *
+     * <p><strong>Note:</strong> This method performs only a shallow copy of the original properties.
+     *
+     * @return a builder for {@link BuilderShape}.
+     */
+    public Builder toBuilder() {
+        var builder = new Builder();
+        return builder;
+    }
+
+    /**
+     * @return returns a new Builder.
+     */
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    /**
+     * Builder for {@link BuilderShape}.
+     */
+    public static final class Builder implements ShapeBuilder<BuilderShape> {
+
+        private Builder() {}
+
+        @Override
+        public Schema schema() {
+            return $SCHEMA;
+        }
+
+        @Override
+        public BuilderShape build() {
+            return new BuilderShape(this);
+        }
+
+        @Override
+        public Builder deserialize(ShapeDeserializer decoder) {
+            decoder.readStruct($SCHEMA, this, $InnerDeserializer.INSTANCE);
+            return this;
+        }
+
+        @Override
+        public Builder deserializeMember(ShapeDeserializer decoder, Schema schema) {
+            decoder.readStruct(schema.assertMemberTargetIs($SCHEMA), this, $InnerDeserializer.INSTANCE);
+            return this;
+        }
+
+        private static final class $InnerDeserializer implements ShapeDeserializer.StructMemberConsumer<Builder> {
+            private static final $InnerDeserializer INSTANCE = new $InnerDeserializer();
+
+            @Override
+            public void accept(Builder builder, Schema member, ShapeDeserializer de) {}
+        }
+    }
+}
+

codegen/plugins/types-codegen/src/test/resources/software/amazon/smithy/java/codegen/types/test-cases/naming-conflict/expected/List.java

@@ -0,0 +1,114 @@
+
+package software.amazon.smithy.java.example.standalone.model;
+
+import java.util.Objects;
+import software.amazon.smithy.java.core.schema.Schema;
+import software.amazon.smithy.java.core.schema.SerializableStruct;
+import software.amazon.smithy.java.core.schema.ShapeBuilder;
+import software.amazon.smithy.java.core.serde.ShapeDeserializer;
+import software.amazon.smithy.java.core.serde.ShapeSerializer;
+import software.amazon.smithy.java.core.serde.ToStringSerializer;
+import software.amazon.smithy.model.shapes.ShapeId;
+import software.amazon.smithy.utils.SmithyGenerated;
+
+@SmithyGenerated
+public final class List implements SerializableStruct {
+
+    public static final Schema $SCHEMA = Schemas.LIST;
+
+    public static final ShapeId $ID = $SCHEMA.id();
+
+    private List(Builder builder) {
+    }
+
+    @Override
+    public String toString() {
+        return ToStringSerializer.serialize(this);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other == this) {
+            return true;
+        }
+        return other != null && getClass() == other.getClass();
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash();
+    }
+
+    @Override
+    public Schema schema() {
+        return $SCHEMA;
+    }
+
+    @Override
+    public void serializeMembers(ShapeSerializer serializer) {
+
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public <T> T getMemberValue(Schema member) {
+        throw new IllegalArgumentException("Attempted to get non-existent member: " + member.id());
+    }
+
+    /**
+     * Create a new builder containing all the current property values of this object.
+     *
+     * <p><strong>Note:</strong> This method performs only a shallow copy of the original properties.
+     *
+     * @return a builder for {@link List}.
+     */
+    public Builder toBuilder() {
+        var builder = new Builder();
+        return builder;
+    }
+
+    /**
+     * @return returns a new Builder.
+     */
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    /**
+     * Builder for {@link List}.
+     */
+    public static final class Builder implements ShapeBuilder<List> {
+
+        private Builder() {}
+
+        @Override
+        public Schema schema() {
+            return $SCHEMA;
+        }
+
+        @Override
+        public List build() {
+            return new List(this);
+        }
+
+        @Override
+        public Builder deserialize(ShapeDeserializer decoder) {
+            decoder.readStruct($SCHEMA, this, $InnerDeserializer.INSTANCE);
+            return this;
+        }
+
+        @Override
+        public Builder deserializeMember(ShapeDeserializer decoder, Schema schema) {
+            decoder.readStruct(schema.assertMemberTargetIs($SCHEMA), this, $InnerDeserializer.INSTANCE);
+            return this;
+        }
+
+        private static final class $InnerDeserializer implements ShapeDeserializer.StructMemberConsumer<Builder> {
+            private static final $InnerDeserializer INSTANCE = new $InnerDeserializer();
+
+            @Override
+            public void accept(Builder builder, Schema member, ShapeDeserializer de) {}
+        }
+    }
+}
+