Remove unused imports

This commit also adds UnusedImportsCheck Checkstyle module.

test/src/main/java/org/springframework/security/test/web/reactive/server/SecurityMockServerConfigurers.java

@@ -26,9 +26,7 @@ import org.springframework.security.core.context.SecurityContext;
 import org.springframework.security.core.context.SecurityContextImpl;
 import org.springframework.security.core.userdetails.User;
 import org.springframework.security.core.userdetails.UserDetails;
-import org.springframework.security.web.server.csrf.CsrfToken;
 import org.springframework.security.web.server.csrf.CsrfWebFilter;
-import org.springframework.security.web.server.csrf.WebSessionServerCsrfTokenRepository;
 import org.springframework.security.web.server.util.matcher.ServerWebExchangeMatcher;
 import org.springframework.test.web.reactive.server.MockServerConfigurer;
 import org.springframework.test.web.reactive.server.WebTestClient;

test/src/test/java/org/springframework/security/test/context/annotation/SecurityTestExecutionListenerTests.java

@@ -19,7 +19,6 @@ import static org.assertj.core.api.Assertions.assertThat;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.springframework.security.core.Authentication;
 import org.springframework.security.core.context.ReactiveSecurityContextHolder;
 import org.springframework.security.core.context.SecurityContext;
 import org.springframework.security.core.context.SecurityContextHolder;

test/src/test/java/org/springframework/security/test/web/reactive/server/AbstractMockServerConfigurersTests.java

@@ -16,19 +16,15 @@
 
 package org.springframework.security.test.web.reactive.server;
 
-import org.springframework.http.HttpHeaders;
-import org.springframework.http.MediaType;
 import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
 import org.springframework.security.core.userdetails.User;
 import org.springframework.security.core.userdetails.UserDetails;
-import org.springframework.test.web.reactive.server.WebTestClient;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
 import java.security.Principal;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.springframework.security.test.web.reactive.server.SecurityMockServerConfigurers.springSecurity;
 
 /**
  * @author Rob Winch

test/src/test/java/org/springframework/security/test/web/reactive/server/SecurityMockServerConfigurersAnnotatedTests.java

@@ -29,8 +29,6 @@ import org.springframework.security.web.server.context.SecurityContextServerWebE
 import org.springframework.test.context.junit4.SpringRunner;
 import org.springframework.test.web.reactive.server.WebTestClient;
 
-import java.security.Principal;
-
 import static org.springframework.security.test.web.reactive.server.SecurityMockServerConfigurers.mockAuthentication;
 import static org.springframework.security.test.web.reactive.server.SecurityMockServerConfigurers.springSecurity;
 

test/src/test/java/org/springframework/security/test/web/servlet/request/SecurityMockMvcRequestPostProcessorsCsrfTests.java

@@ -29,7 +29,6 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.context.annotation.Bean;
 import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.mock.web.MockHttpServletResponse;
 import org.springframework.mock.web.MockHttpSession;

test/src/test/java/org/springframework/security/test/web/servlet/response/SecurityMockMvcResultMatchersTests.java

@@ -21,7 +21,6 @@ import org.junit.runner.RunWith;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Bean;
-import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
 import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
 import org.springframework.security.core.userdetails.User;

test/src/test/java/org/springframework/security/test/web/servlet/response/SecurityMockWithAuthoritiesMvcResultMatchersTests.java

@@ -28,7 +28,6 @@ import org.junit.runner.RunWith;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Bean;
-import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
 import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
 import org.springframework.security.core.authority.SimpleGrantedAuthority;

test/src/test/java/org/springframework/security/test/web/servlet/showcase/login/AuthenticationTests.java

@@ -27,7 +27,6 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Bean;
-import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
 import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
 import org.springframework.security.core.userdetails.User;

test/src/test/java/org/springframework/security/test/web/servlet/showcase/login/CustomConfigAuthenticationTests.java

@@ -27,7 +27,6 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Bean;
-import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;