Add SpringImportOrderCheck with package support

Add a `SpringImportOrderCheck` to allow spring import ordering with
the option of configuring the project root package.

See gh-62

Author: vpavic

spring-javaformat/spring-javaformat-checkstyle/src/main/java/io/spring/javaformat/checkstyle/check/SpringImportOrderCheck.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2017-2019 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.
+ */
+
+package io.spring.javaformat.checkstyle.check;
+
+import com.puppycrawl.tools.checkstyle.checks.imports.ImportOrderCheck;
+
+/**
+ * Checks that the order of imports follow Spring conventions.
+ *
+ * @author Vedran Pavic
+ */
+public class SpringImportOrderCheck extends ImportOrderCheck {
+
+	private static final String DEFAULT_PROJECT_ROOT_PACKAGE = "org.springframework";
+
+	public SpringImportOrderCheck() {
+		setProjectRootPackage(DEFAULT_PROJECT_ROOT_PACKAGE);
+		setOrdered(true);
+		setSeparated(true);
+		setOption("bottom");
+		setSortStaticImportsAlphabetically(true);
+	}
+
+	public void setProjectRootPackage(String projectRootPackage) {
+		setGroups("java", "/^javax?\\./", "*", projectRootPackage);
+	}
+
+}

spring-javaformat/spring-javaformat-checkstyle/src/main/resources/io/spring/javaformat/checkstyle/spring-checkstyle.xml

@@ -81,13 +81,7 @@
 		<module name="com.puppycrawl.tools.checkstyle.checks.imports.UnusedImportsCheck">
 			<property name="processJavadoc" value="true" />
 		</module>
-		<module name="com.puppycrawl.tools.checkstyle.checks.imports.ImportOrderCheck">
-			<property name="groups" value="java,/^javax?\./,*,org.springframework" />
-			<property name="ordered" value="true" />
-			<property name="separated" value="true" />
-			<property name="option" value="bottom" />
-			<property name="sortStaticImportsAlphabetically" value="true" />
-		</module>
+		<module name="io.spring.javaformat.checkstyle.check.SpringImportOrderCheck"/>
 
 		<!-- Javadoc Comments -->
 		<module name="com.puppycrawl.tools.checkstyle.checks.javadoc.JavadocTypeCheck">