Remove unnecessary dependencies on JDK modules not in java.base.

.changes/next-release/feature-AWSSDKforJavav2-d2d8d5d.json

@@ -0,0 +1,6 @@
+{
+    "category": "AWS SDK for Java v2", 
+    "contributor": "", 
+    "type": "feature", 
+    "description": "Remove unnecessary dependencies on JDK modules not in java.base. This didn't remove all of the dependencies on such modules, just the unnecessary ones."
+}

build-tools/src/main/java/software/amazon/awssdk/buildtools/checkstyle/NonJavaBaseModuleCheck.java

@@ -0,0 +1,195 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package software.amazon.awssdk.buildtools.checkstyle;
+
+import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
+import com.puppycrawl.tools.checkstyle.api.DetailAST;
+import com.puppycrawl.tools.checkstyle.api.FullIdent;
+import com.puppycrawl.tools.checkstyle.api.TokenTypes;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.regex.Pattern;
+
+/**
+ * Verify that we're not using classes in rt.jar that aren't exported via the java.base module.
+ *
+ * If anything fails this check, it increases our module dependencies. If you absolutely must use one of these
+ * (e.g. java.beans) because it's fundamental to your functionality, you can suppress this checkstyle rule via
+ * {@link #setLegalPackages(String...)}, but know that it is not free - you're essentially adding a dependency
+ * for customers that use the module path.
+ */
+public class NonJavaBaseModuleCheck extends AbstractCheck {
+    private static final List<String> ILLEGAL_PACKAGES = Arrays.asList(
+        "java",
+        "javax",
+        "sun",
+        "apple",
+        "com.apple",
+        "com.oracle");
+
+    private static final Set<String> LEGAL_PACKAGES = new HashSet<>(Arrays.asList(
+        "java.io",
+        "java.lang",
+        "java.lang.annotation",
+        "java.lang.invoke",
+        "java.lang.module",
+        "java.lang.ref",
+        "java.lang.reflect",
+        "java.math",
+        "java.net",
+        "java.net.spi",
+        "java.nio",
+        "java.nio.channels",
+        "java.nio.channels.spi",
+        "java.nio.charset",
+        "java.nio.charset.spi",
+        "java.nio.file",
+        "java.nio.file.attribute",
+        "java.nio.file.spi",
+        "java.security",
+        "java.security.acl",
+        "java.security.cert",
+        "java.security.interfaces",
+        "java.security.spec",
+        "java.text",
+        "java.text.spi",
+        "java.time",
+        "java.time.chrono",
+        "java.time.format",
+        "java.time.temporal",
+        "java.time.zone",
+        "java.util",
+        "java.util.concurrent",
+        "java.util.concurrent.atomic",
+        "java.util.concurrent.locks",
+        "java.util.function",
+        "java.util.jar",
+        "java.util.regex",
+        "java.util.spi",
+        "java.util.stream",
+        "java.util.jar",
+        "java.util.zip",
+        "javax.crypto",
+        "javax.crypto.interfaces",
+        "javax.crypto.spec",
+        "javax.net",
+        "javax.net.ssl",
+        "javax.security.auth",
+        "javax.security.auth.callback",
+        "javax.security.auth.login",
+        "javax.security.auth.spi",
+        "javax.security.auth.x500",
+        "javax.security.cert"));
+
+    private static final Pattern CLASSNAME_START_PATTERN = Pattern.compile("[A-Z]");
+
+    private String currentSdkPackage;
+
+    private HashMap<String, Set<String>> additionalLegalPackagesBySdkPackage = new HashMap<>();
+
+    /**
+     * Additional legal packages are formatted as "sdk.package.name:jdk.package.name,sdk.package.name2:jdk.package.name2".
+     * Multiple SDK packages can be repeated.
+     */
+    public void setLegalPackages(String... legalPackages) {
+        for (String additionalLegalPackage : legalPackages) {
+            String[] splitPackage = additionalLegalPackage.split(":", 2);
+            if (splitPackage.length != 2) {
+                throw new IllegalArgumentException("Invalid legal package definition '" + additionalLegalPackage + "'. Expected"
+                                                   + " format is sdk.package.name:jdk.package.name");
+            }
+
+            this.additionalLegalPackagesBySdkPackage.computeIfAbsent(splitPackage[0], k -> new HashSet<>())
+                                                    .add(splitPackage[1]);
+        }
+    }
+
+    @Override
+    public int[] getDefaultTokens() {
+        return getRequiredTokens();
+    }
+
+    @Override
+    public int[] getAcceptableTokens() {
+        return getRequiredTokens();
+    }
+
+    @Override
+    public int[] getRequiredTokens() {
+        return new int[] { TokenTypes.IMPORT, TokenTypes.STATIC_IMPORT, TokenTypes.PACKAGE_DEF };
+    }
+
+    @Override
+    public void visitToken(DetailAST ast) {
+        if (ast.getType() == TokenTypes.PACKAGE_DEF) {
+            handlePackageDefToken(ast);
+            return;
+        }
+
+        handleImportToken(ast);
+    }
+
+    private void handlePackageDefToken(DetailAST ast) {
+        this.currentSdkPackage = FullIdent.createFullIdent(ast.getLastChild().getPreviousSibling()).getText();
+    }
+
+    private void handleImportToken(DetailAST ast) {
+        FullIdent importIdentifier;
+        if (ast.getType() == TokenTypes.IMPORT) {
+            importIdentifier = FullIdent.createFullIdentBelow(ast);
+        } else {
+            importIdentifier = FullIdent.createFullIdent(ast.getFirstChild().getNextSibling());
+        }
+
+        String importText = importIdentifier.getText();
+        if (isIllegalImport(importText) && !isLegalImport(importText)) {
+            log(ast, "Import '" + importText + "' uses a JDK class that is not in java.base. This essentially adds an "
+                     + "additional module dependency. Don't suppress this rule unless it's absolutely required, and only "
+                     + "suppress the specific package you need via checkstyle.xml instead of suppressing the entire rule.");
+        }
+    }
+
+    private boolean isIllegalImport(String importText) {
+        for (String illegalPackage : ILLEGAL_PACKAGES) {
+            if (importText.startsWith(illegalPackage + ".")) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    private boolean isLegalImport(String importText) {
+        String importPackageWithTrailingDot = CLASSNAME_START_PATTERN.split(importText, 2)[0];
+        String importPackage = importText.substring(0, importPackageWithTrailingDot.length() - 1);
+
+        if (LEGAL_PACKAGES.contains(importPackage)) {
+            return true;
+        }
+
+        if (additionalLegalPackagesBySdkPackage.entrySet()
+                                               .stream()
+                                               .anyMatch(e -> currentSdkPackage.startsWith(e.getKey()) &&
+                                                              e.getValue().contains(importPackage))) {
+            return true;
+        }
+
+        return false;
+    }
+}

build-tools/src/main/resources/software/amazon/awssdk/checkstyle-suppressions.xml

@@ -50,4 +50,7 @@
     <!-- Ignore usage of sslContext.newHandler for NettyUtils.!-->
     <suppress checks="Regexp"
               files=".*NettyUtils\.java$"/>
+
+    <!-- Allow non-java.base usage in tests -->
+    <suppress checks="software.amazon.awssdk.buildtools.checkstyle.NonJavaBaseModuleCheck" files=".*testutils.*"/>
 </suppressions>

build-tools/src/main/resources/software/amazon/awssdk/checkstyle.xml

@@ -431,6 +431,18 @@
             <property name="packageToCheck" value="software.amazon.awssdk.http.nio.netty" />
             <property name="illegalPkgs" value="software.amazon.awssdk.utils.Logger,org.slf4j.Logger"/>
         </module>
+
+        <module name="software.amazon.awssdk.buildtools.checkstyle.NonJavaBaseModuleCheck">
+            <!--
+            codegen: Allowed to use classes from java.compiler, because poet requires them.
+            aws-query-protocol: Allowed to use classes from java.xml for XML parsing.
+            protocol-tests-core: Allows to use classes from java.xml for XML assertions.
+            dynamodb-enhanced: Allowed to use classes from java.beans for bean processing.
+            release-scripts: Allowed to use classes from java.xml for XML writing.
+            sdk-benchmarks: Allowed to use classes from javax.servlet.http for benchmark servlets.
+            -->
+            <property name="legalPackages" value="software.amazon.awssdk.codegen:javax.lang.model, software.amazon.awssdk.codegen:javax.lang.model.element, software.amazon.awssdk.codegen:javax.lang.model.type, software.amazon.awssdk.protocols.query:javax.xml.stream, software.amazon.awssdk.protocols.query:javax.xml.stream.events, software.amazon.awssdk.protocol.asserts.marshalling:javax.xml, software.amazon.awssdk.protocol.asserts.marshalling:javax.xml.parsers, software.amazon.awssdk.protocol.asserts.marshalling:javax.xml.transform, software.amazon.awssdk.protocol.asserts.marshalling:javax.xml.transform.dom, software.amazon.awssdk.protocol.asserts.marshalling:javax.xml.transform.stream, software.amazon.awssdk.enhanced.dynamodb.mapper:java.beans, software.amazon.awssdk.release:javax.xml, software.amazon.awssdk.release:javax.xml.parsers, software.amazon.awssdk.release:javax.xml.transform, software.amazon.awssdk.release:javax.xml.xpath, software.amazon.awssdk.release:javax.xml.transform.dom, software.amazon.awssdk.release:javax.xml.transform.stream, software.amazon.awssdk.benchmark:javax.servlet.http"/>
+        </module>
     </module>
 
         <!-- Enforce maximum line lengths. -->

codegen/src/main/java/software/amazon/awssdk/codegen/poet/model/AbstractMemberSetters.java

@@ -15,14 +15,19 @@
 
 package software.amazon.awssdk.codegen.poet.model;
 
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singleton;
 import static software.amazon.awssdk.codegen.poet.model.TypeProvider.ShapeTransformation.USE_BUILDER_IMPL;
 
+import com.squareup.javapoet.AnnotationSpec;
 import com.squareup.javapoet.ClassName;
 import com.squareup.javapoet.CodeBlock;
 import com.squareup.javapoet.MethodSpec;
 import com.squareup.javapoet.ParameterSpec;
 import com.squareup.javapoet.TypeName;
+// CHECKSTYLE:OFF java.beans is required for services that use names starting with 'set' to fix bean-based marshalling.
 import java.beans.Transient;
+// CHECKSTYLE:ON
 import java.util.Optional;
 import java.util.stream.Collectors;
 import javax.lang.model.element.Modifier;
@@ -85,11 +90,19 @@ protected MethodSpec.Builder fluentSetterBuilder(String methodName, ParameterSpe
         return MethodSpec.methodBuilder(methodName)
                          .addParameter(setterParam)
                          .addAnnotation(Override.class)
-                         .addAnnotation(Transient.class)
+                         .addAnnotations(maybeTransient(methodName))
                          .returns(returnType)
                          .addModifiers(Modifier.PUBLIC, Modifier.FINAL);
     }
 
+    private Iterable<AnnotationSpec> maybeTransient(String methodName) {
+        if (methodName.startsWith("set")) {
+            return singleton(AnnotationSpec.builder(Transient.class).build());
+        }
+
+        return emptyList();
+    }
+
     protected MethodSpec.Builder beanStyleSetterBuilder() {
         return beanStyleSetterBuilder(memberAsBeanStyleParameter(), memberModel().getBeanStyleSetterMethodName());
     }