Use Checkstyle to police accidental use of unwanted imports

Closes gh-11271

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/mvc/HalBrowserMvcEndpointDisabledIntegrationTests.java

@@ -16,7 +16,6 @@
 
 package org.springframework.boot.actuate.endpoint.mvc;
 
-import com.google.common.net.HttpHeaders;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -26,6 +25,7 @@ import org.springframework.boot.SpringApplication;
 import org.springframework.boot.actuate.autoconfigure.MinimalActuatorHypermediaApplication;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.context.TestPropertySource;

spring-boot-parent/pom.xml

@@ -305,7 +305,7 @@
 						<dependency>
 							<groupId>com.puppycrawl.tools</groupId>
 							<artifactId>checkstyle</artifactId>
-							<version>7.1.1</version>
+							<version>8.5</version>
 						</dependency>
 					</dependencies>
 				</plugin>

spring-boot-parent/src/checkstyle/checkstyle.xml

@@ -72,7 +72,10 @@
 			<property name="excludes"
 				value="org.assertj.core.api.Assertions.*, org.junit.Assert.*, org.junit.Assume.*, org.junit.internal.matchers.ThrowableMessageMatcher.*, org.hamcrest.CoreMatchers.*, org.hamcrest.Matchers.*, org.springframework.boot.configurationprocessor.ConfigurationMetadataMatchers.*, org.springframework.boot.configurationprocessor.TestCompiler.*, org.springframework.boot.test.autoconfigure.AutoConfigurationImportedCondition.*, org.mockito.Mockito.*, org.mockito.BDDMockito.*, org.mockito.Matchers.*, org.springframework.restdocs.mockmvc.MockMvcRestDocumentation.*, org.springframework.restdocs.hypermedia.HypermediaDocumentation.*, org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*, org.springframework.test.web.servlet.result.MockMvcResultMatchers.*, org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors.*, org.springframework.security.test.web.servlet.setup.SecurityMockMvcConfigurers.*, org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo, org.springframework.test.web.client.match.MockRestRequestMatchers.*, org.springframework.test.web.client.response.MockRestResponseCreators.*" />
 		</module>
-		<module name="com.puppycrawl.tools.checkstyle.checks.imports.IllegalImportCheck" />
+		<module name="com.puppycrawl.tools.checkstyle.checks.imports.IllegalImportCheck">
+			<property name="illegalPkgs" value="sun, org.apache.commons.(?!codec|dbcp|dbcp2|logging|pool|pool2).*, com.google.common.(?!cache).*"/>
+			<property name="regexp" value="true"/>
+		</module>
 		<module name="com.puppycrawl.tools.checkstyle.checks.imports.RedundantImportCheck" />
 		<module name="com.puppycrawl.tools.checkstyle.checks.imports.UnusedImportsCheck">
 			<property name="processJavadoc" value="true" />