Add Gradle Java boilerplate (#1)

.baseline/checkstyle/checkstyle-suppressions.xml

@@ -0,0 +1,41 @@
+<?xml version="1.0"?>
+<!DOCTYPE suppressions PUBLIC
+    "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
+    "https://checkstyle.org/dtds/suppressions_1_2.dtd">
+<!--
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License 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.
+-->
+
+<suppressions>
+    <!-- Suppress test classes -->
+    <suppress files="[/\\]src[/\\].*[Tt]est[/\\](java|groovy)[/\\]" checks="Javadoc*" />
+    <suppress files="[/\\]src[/\\].*[Tt]est[/\\](java|groovy)[/\\]" checks="VariableDeclarationUsageDistance" />
+    <suppress files="[/\\]src[/\\].*[Tt]est[/\\](java|groovy)[/\\]" checks="VisibilityModifier" />
+    <suppress files="[/\\]src[/\\].*[Tt]est[/\\](java|groovy)[/\\]" checks="AvoidStaticImport" />
+    <suppress files="[/\\]src[/\\].*[Tt]est[/\\](java|groovy)[/\\]" id="BanSystemOut" />
+    <suppress files="[/\\]src[/\\].*[Tt]est[/\\](java|groovy)[/\\]" id="BanSystemErr" />
+    <suppress files="[/\\]src[/\\].*[Tt]est[/\\](java|groovy)[/\\]" id="BanGuavaTesting" />
+
+    <!-- Suppress test resources -->
+    <suppress files="[/\\]src[/\\]test[/\\]resources.*" checks="." />
+
+    <!-- JavadocStyle enforces existence of package-info.java package-level Javadoc; we consider this a bug. -->
+    <suppress files="package-info.java" checks="JavadocStyle" />
+
+    <!-- non-code classes -->
+    <suppress files="\.(bdr|eot|gif|gzip|jar|json|otf|png|svg|ttf|woff|zip)$" checks="FileTabCharacter" />
+    <suppress files="\.(bdr|eot|gif|gzip|jar|json|otf|png|svg|ttf|woff|zip)$" checks="NewlineAtEndOfFile" />
+
+    <!-- Generated code should not be subjected to checkstyle. -->
+    <suppress files="[/\\].*[/\\]generated.*[/\\]" checks="." />
+</suppressions>

.baseline/copyright/copyright-header-java.txt

@@ -0,0 +1,13 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License 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.
+ */