Use toLowerCase() and toUpperCase() with Locale.ENGLISH

This commit updates all `toLowerCase()` and `toUpperCase` invocations to
use the variant that takes a `Locale` to avoid locale-specific side
effect.

Closes gh-12213

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/cloudfoundry/CloudFoundrySecurityInterceptor.java

 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.boot.actuate.cloudfoundry;
 
+import java.util.Locale;
+
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
@@ -107,7 +109,7 @@ class CloudFoundrySecurityInterceptor extends HandlerInterceptorAdapter {
 		String authorization = request.getHeader("Authorization");
 		String bearerPrefix = "bearer ";
 		if (authorization == null
-				|| !authorization.toLowerCase().startsWith(bearerPrefix)) {
+				|| !authorization.toLowerCase(Locale.ENGLISH).startsWith(bearerPrefix)) {
 			throw new CloudFoundryAuthorizationException(Reason.MISSING_AUTHORIZATION,
 					"Authorization header is missing or invalid");
 		}

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/DataSourcePublicMetrics.java

 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -19,6 +19,7 @@ package org.springframework.boot.actuate.endpoint;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.LinkedHashSet;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 
@@ -104,7 +105,7 @@ public class DataSourcePublicMetrics implements PublicMetrics {
 			return "datasource.primary";
 		}
 		if (name.length() > DATASOURCE_SUFFIX.length()
-				&& name.toLowerCase().endsWith(DATASOURCE_SUFFIX.toLowerCase())) {
+				&& name.toLowerCase(Locale.ENGLISH).endsWith(DATASOURCE_SUFFIX.toLowerCase())) {
 			name = name.substring(0, name.length() - DATASOURCE_SUFFIX.length());
 		}
 		return "datasource." + name;

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/HealthEndpoint.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.boot.actuate.endpoint;
 
+import java.util.Locale;
 import java.util.Map;
 
 import org.springframework.boot.actuate.health.CompositeHealthIndicator;
@@ -91,7 +92,7 @@ public class HealthEndpoint extends AbstractEndpoint<Health> {
 	 * @return the key
 	 */
 	private String getKey(String name) {
-		int index = name.toLowerCase().indexOf("healthindicator");
+		int index = name.toLowerCase(Locale.ENGLISH).indexOf("healthindicator");
 		if (index > 0) {
 			return name.substring(0, index);
 		}

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/SystemPublicMetrics.java

 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -24,6 +24,7 @@ import java.lang.management.ThreadMXBean;
 import java.util.Collection;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Locale;
 
 import org.springframework.boot.actuate.metrics.Metric;
 import org.springframework.core.Ordered;
@@ -188,7 +189,7 @@ public class SystemPublicMetrics implements PublicMetrics, Ordered {
 	 * @return a metric friendly name
 	 */
 	private String beautifyGcName(String name) {
-		return StringUtils.replace(name, " ", "_").toLowerCase();
+		return StringUtils.replace(name, " ", "_").toLowerCase(Locale.ENGLISH);
 	}
 
 }

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/jmx/LoggersEndpointMBean.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.boot.actuate.endpoint.jmx;
 
+import java.util.Locale;
+
 import com.fasterxml.jackson.databind.ObjectMapper;
 
 import org.springframework.boot.actuate.endpoint.Endpoint;
@@ -52,7 +54,7 @@ public class LoggersEndpointMBean extends EndpointMBean {
 	@ManagedOperation(description = "Set log level for a given logger")
 	public void setLogLevel(String loggerName, String logLevel) {
 		Assert.notNull(logLevel, "LogLevel must not be null");
-		LogLevel level = LogLevel.valueOf(logLevel.toUpperCase());
+		LogLevel level = LogLevel.valueOf(logLevel.toUpperCase(Locale.ENGLISH));
 		getEndpoint().setLogLevel(loggerName, level);
 	}
 

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/mvc/HealthMvcEndpoint.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -20,6 +20,7 @@ import java.security.Principal;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 
 import javax.servlet.http.HttpServletRequest;
@@ -151,7 +152,7 @@ public class HealthMvcEndpoint extends AbstractEndpointMvcAdapter<HealthEndpoint
 	private HttpStatus getStatus(Health health) {
 		String code = health.getStatus().getCode();
 		if (code != null) {
-			code = code.toLowerCase().replace('_', '-');
+			code = code.toLowerCase(Locale.ENGLISH).replace('_', '-');
 			for (String candidate : RelaxedNames.forCamelCase(code)) {
 				HttpStatus status = this.statusMapping.get(candidate);
 				if (status != null) {

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/mvc/LoggersMvcEndpoint.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.boot.actuate.endpoint.mvc;
 
+import java.util.Locale;
 import java.util.Map;
 
 import org.springframework.boot.actuate.endpoint.LoggersEndpoint;
@@ -78,7 +79,8 @@ public class LoggersMvcEndpoint extends EndpointMvcAdapter {
 	private LogLevel getLogLevel(Map<String, String> configuration) {
 		String level = configuration.get("configuredLevel");
 		try {
-			return (level == null ? null : LogLevel.valueOf(level.toUpperCase()));
+			return (level == null ? null
+					: LogLevel.valueOf(level.toUpperCase(Locale.ENGLISH)));
 		}
 		catch (IllegalArgumentException ex) {
 			throw new InvalidLogLevelException(level);

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/trace/WebRequestTraceFilter.java

@@ -23,6 +23,7 @@ import java.util.Enumeration;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
@@ -165,7 +166,7 @@ public class WebRequestTraceFilter extends OncePerRequestFilter implements Order
 		Enumeration<String> names = request.getHeaderNames();
 		while (names.hasMoreElements()) {
 			String name = names.nextElement();
-			if (!excludedHeaders.contains(name.toLowerCase())) {
+			if (!excludedHeaders.contains(name.toLowerCase(Locale.ENGLISH))) {
 				headers.put(name, getHeaderValue(request, name));
 			}
 		}

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cache/CacheCondition.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.boot.autoconfigure.cache;
 
+import java.util.Locale;
+
 import org.springframework.boot.autoconfigure.condition.ConditionMessage;
 import org.springframework.boot.autoconfigure.condition.ConditionOutcome;
 import org.springframework.boot.autoconfigure.condition.SpringBootCondition;
@@ -50,7 +52,8 @@ class CacheCondition extends SpringBootCondition {
 		}
 		CacheType cacheType = CacheConfigurations
 				.getType(((AnnotationMetadata) metadata).getClassName());
-		String value = resolver.getProperty("type").replace('-', '_').toUpperCase();
+		String value = resolver.getProperty("type").replace('-', '_')
+				.toUpperCase(Locale.ENGLISH);
 		if (value.equals(cacheType.name())) {
 			return ConditionOutcome.match(message.because(value + " cache type"));
 		}

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/OnBeanCondition.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -24,6 +24,7 @@ import java.util.Collections;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Set;
 
 import org.springframework.beans.factory.BeanFactory;
@@ -399,7 +400,7 @@ class OnBeanCondition extends SpringBootCondition implements ConfigurationCondit
 				string.append(StringUtils.collectionToCommaDelimitedString(this.types));
 			}
 			string.append("; SearchStrategy: ");
-			string.append(this.strategy.toString().toLowerCase());
+			string.append(this.strategy.toString().toLowerCase(Locale.ENGLISH));
 			string.append(")");
 			return string.toString();
 		}

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/cassandra/CassandraDataAutoConfiguration.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -17,6 +17,7 @@
 package org.springframework.boot.autoconfigure.data.cassandra;
 
 import java.util.List;
+import java.util.Locale;
 
 import com.datastax.driver.core.Cluster;
 import com.datastax.driver.core.Session;
@@ -114,7 +115,8 @@ public class CassandraDataAutoConfiguration {
 		session.setKeyspaceName(this.properties.getKeyspaceName());
 		String name = this.propertyResolver.getProperty("schemaAction",
 				SchemaAction.NONE.name());
-		SchemaAction schemaAction = SchemaAction.valueOf(name.toUpperCase());
+		SchemaAction schemaAction = SchemaAction.valueOf(
+				name.toUpperCase(Locale.ENGLISH));
 		session.setSchemaAction(schemaAction);
 		return session;
 	}

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/EmbeddedDatabaseConnection.java

 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -18,6 +18,7 @@ package org.springframework.boot.autoconfigure.jdbc;
 
 import java.sql.Connection;
 import java.sql.SQLException;
+import java.util.Locale;
 
 import javax.sql.DataSource;
 
@@ -173,7 +174,7 @@ public enum EmbeddedDatabaseConnection {
 			if (productName == null) {
 				return false;
 			}
-			productName = productName.toUpperCase();
+			productName = productName.toUpperCase(Locale.ENGLISH);
 			EmbeddedDatabaseConnection[] candidates = EmbeddedDatabaseConnection.values();
 			for (EmbeddedDatabaseConnection candidate : candidates) {
 				if (candidate != NONE && productName.contains(candidate.name())) {

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/SessionAutoConfiguration.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.boot.autoconfigure.session;
 
+import java.util.Locale;
+
 import javax.annotation.PostConstruct;
 
 import org.springframework.beans.factory.ObjectProvider;
@@ -100,7 +102,8 @@ public class SessionAutoConfiguration {
 				if (storeType != null) {
 					throw new IllegalArgumentException("No session repository could be "
 							+ "auto-configured, check your configuration (session store "
-							+ "type is '" + storeType.name().toLowerCase() + "')");
+							+ "type is '" + storeType.name().toLowerCase(Locale.ENGLISH)
+							+ "')");
 				}
 				throw new IllegalArgumentException("No Spring Session store is "
 						+ "configured: set the 'spring.session.store-type' property");

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/SessionCondition.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.boot.autoconfigure.session;
 
+import java.util.Locale;
+
 import org.springframework.boot.autoconfigure.condition.ConditionMessage;
 import org.springframework.boot.autoconfigure.condition.ConditionOutcome;
 import org.springframework.boot.autoconfigure.condition.SpringBootCondition;
@@ -45,7 +47,8 @@ class SessionCondition extends SpringBootCondition {
 			return ConditionOutcome.noMatch(
 					message.didNotFind("spring.session.store-type property").atAll());
 		}
-		String value = resolver.getProperty("store-type").replace('-', '_').toUpperCase();
+		String value = resolver.getProperty("store-type").replace('-', '_')
+				.toUpperCase(Locale.ENGLISH);
 		if (value.equals(sessionStoreType.name())) {
 			return ConditionOutcome.match(message
 					.found("spring.session.store-type property").items(sessionStoreType));

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/AbstractErrorController.java

 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -18,6 +18,7 @@ package org.springframework.boot.autoconfigure.web;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 
 import javax.servlet.http.HttpServletRequest;
@@ -78,7 +79,7 @@ public abstract class AbstractErrorController implements ErrorController {
 		if (parameter == null) {
 			return false;
 		}
-		return !"false".equals(parameter.toLowerCase());
+		return !"false".equals(parameter.toLowerCase(Locale.ENGLISH));
 	}
 
 	protected HttpStatus getStatus(HttpServletRequest request) {

spring-boot-cli/src/main/java/org/springframework/boot/cli/command/archive/ArchiveCommand.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -27,6 +27,7 @@ import java.net.URL;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Locale;
 import java.util.jar.Manifest;
 
 import groovy.lang.Grab;
@@ -129,9 +130,10 @@ abstract class ArchiveCommand extends OptionParsingCommand {
 					+ this.type + " and at least one source file must be specified");
 
 			File output = new File((String) nonOptionArguments.remove(0));
-			Assert.isTrue(output.getName().toLowerCase().endsWith("." + this.type),
-					"The output '" + output + "' is not a " + this.type.toUpperCase()
-							+ " file.");
+			Assert.isTrue(
+					output.getName().toLowerCase(Locale.ENGLISH).endsWith("." + this.type),
+					"The output '" + output + "' is not a " + this.type.toUpperCase(
+							Locale.ENGLISH) + " file.");
 			deleteIfExists(output);
 
 			GroovyCompiler compiler = createCompiler(options);

spring-boot-integration-tests/spring-boot-launch-script-tests/src/test/java/org/springframework/boot/launchscript/SysVinitLaunchScriptIT.java

@@ -24,6 +24,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.concurrent.TimeUnit;
 import java.util.regex.Pattern;
 
@@ -306,7 +307,8 @@ public class SysVinitLaunchScriptIT {
 	private String buildImage(DockerClient docker) {
 		String dockerfile = "src/test/resources/conf/" + this.os + "/" + this.version
 				+ "/Dockerfile";
-		String tag = "spring-boot-it/" + this.os.toLowerCase() + ":" + this.version;
+		String tag = "spring-boot-it/" + this.os.toLowerCase(Locale.ENGLISH) + ":"
+				+ this.version;
 		BuildImageResultCallback resultCallback = new BuildImageResultCallback() {
 
 			private List<BuildResponseItem> items = new ArrayList<BuildResponseItem>();

spring-boot-samples/spring-boot-sample-data-gemfire/src/main/java/sample/data/gemfire/service/GemstoneServiceImpl.java

 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -19,6 +19,7 @@ package sample.data.gemfire.service;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Locale;
 
 import javax.annotation.PostConstruct;
 
@@ -126,7 +127,7 @@ public class GemstoneServiceImpl implements GemstoneService {
 	}
 
 	Gemstone validate(Gemstone gemstone) {
-		if (!APPROVED_GEMS.contains(gemstone.getName().toUpperCase())) {
+		if (!APPROVED_GEMS.contains(gemstone.getName().toUpperCase(Locale.ENGLISH))) {
 			// NOTE if the Gemstone is not valid, throw error...
 			// Should cause transaction to rollback in GemFire!
 			System.err.printf("Illegal Gemstone [%1$s]!%n", gemstone.getName());

spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/properties/AnnotationsPropertySource.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -23,6 +23,7 @@ import java.util.Collections;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.regex.Matcher;
@@ -158,7 +159,7 @@ public class AnnotationsPropertySource extends EnumerablePropertySource<Class<?>
 					matcher.group(1) + '-' + StringUtils.uncapitalize(matcher.group(2)));
 		}
 		matcher.appendTail(result);
-		return result.toString().toLowerCase();
+		return result.toString().toLowerCase(Locale.ENGLISH);
 	}
 
 	private String dotAppend(String prefix, String postfix) {

spring-boot-tools/spring-boot-configuration-metadata/src/main/java/org/springframework/boot/configurationmetadata/JsonReader.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -23,6 +23,7 @@ import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Locale;
 
 import org.json.JSONArray;
 import org.json.JSONObject;
@@ -183,7 +184,7 @@ class JsonReader {
 	private Deprecation.Level parseDeprecationLevel(String value) {
 		if (value != null) {
 			try {
-				return Deprecation.Level.valueOf(value.toUpperCase());
+				return Deprecation.Level.valueOf(value.toUpperCase(Locale.ENGLISH));
 			}
 			catch (IllegalArgumentException e) {
 				// let's use the default

spring-boot-tools/spring-boot-configuration-processor/src/main/java/org/springframework/boot/configurationprocessor/metadata/ConfigurationMetadata.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -23,6 +23,7 @@ import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.ListIterator;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 
@@ -197,7 +198,7 @@ public class ConfigurationMetadata {
 			previous = current;
 
 		}
-		return dashed.toString().toLowerCase();
+		return dashed.toString().toLowerCase(Locale.ENGLISH);
 	}
 
 	private static <T extends Comparable<T>> List<T> flattenValues(Map<?, List<T>> map) {

spring-boot-tools/spring-boot-loader-tools/src/main/java/org/springframework/boot/loader/tools/Layouts.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -21,6 +21,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 
@@ -45,13 +46,14 @@ public final class Layouts {
 		if (file == null) {
 			throw new IllegalArgumentException("File must not be null");
 		}
-		if (file.getName().toLowerCase().endsWith(".jar")) {
+		if (file.getName().toLowerCase(Locale.ENGLISH).endsWith(".jar")) {
 			return new Jar();
 		}
-		if (file.getName().toLowerCase().endsWith(".war")) {
+		if (file.getName().toLowerCase(Locale.ENGLISH).endsWith(".war")) {
 			return new War();
 		}
-		if (file.isDirectory() || file.getName().toLowerCase().endsWith(".zip")) {
+		if (file.isDirectory()
+				|| file.getName().toLowerCase(Locale.ENGLISH).endsWith(".zip")) {
 			return new Expanded();
 		}
 		throw new IllegalStateException("Unable to deduce layout for '" + file + "'");

spring-boot-tools/spring-boot-loader-tools/src/main/java/org/springframework/boot/loader/tools/RunProcess.java

 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -23,6 +23,7 @@ import java.io.InputStreamReader;
 import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Locale;
 
 import org.springframework.util.ReflectionUtils;
 
@@ -128,7 +129,8 @@ public class RunProcess {
 	// There's a bug in the Windows VM (https://bugs.openjdk.java.net/browse/JDK-8023130)
 	// that means we need to avoid inheritIO
 	private static boolean isInheritIOBroken() {
-		if (!System.getProperty("os.name", "none").toLowerCase().contains("windows")) {
+		if (!System.getProperty("os.name", "none").toLowerCase(Locale.ENGLISH)
+				.contains("windows")) {
 			return false;
 		}
 		String runtime = System.getProperty("java.runtime.version");

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/PropertiesLauncher.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -27,6 +27,7 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Properties;
 import java.util.Set;
 import java.util.jar.Manifest;
@@ -489,7 +490,7 @@ public class PropertiesLauncher extends Launcher {
 	}
 
 	private Archive getArchive(File file) throws IOException {
-		String name = file.getName().toLowerCase();
+		String name = file.getName().toLowerCase(Locale.ENGLISH);
 		if (name.endsWith(".jar") || name.endsWith(".zip")) {
 			return new JarFileArchive(file);
 		}
@@ -566,7 +567,8 @@ public class PropertiesLauncher extends Launcher {
 		if (path.startsWith("./")) {
 			path = path.substring(2);
 		}
-		if (path.toLowerCase().endsWith(".jar") || path.toLowerCase().endsWith(".zip")) {
+		String lowercasePath = path.toLowerCase(Locale.ENGLISH);
+		if (lowercasePath.endsWith(".jar") || lowercasePath.endsWith(".zip")) {
 			return path;
 		}
 		if (path.endsWith("/*")) {

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/util/SystemPropertyUtils.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -17,6 +17,7 @@
 package org.springframework.boot.loader.util;
 
 import java.util.HashSet;
+import java.util.Locale;
 import java.util.Properties;
 import java.util.Set;
 
@@ -188,7 +189,8 @@ public abstract class SystemPropertyUtils {
 			}
 			if (propVal == null) {
 				// Try uppercase with underscores as well.
-				propVal = System.getenv(key.toUpperCase().replace('.', '_'));
+				propVal = System.getenv(key.toUpperCase(Locale.ENGLISH)
+						.replace('.', '_'));
 			}
 			if (propVal != null) {
 				return propVal;

spring-boot/src/main/java/org/springframework/boot/ansi/AnsiOutput.java

 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.boot.ansi;
 
+import java.util.Locale;
+
 import org.springframework.util.Assert;
 
 /**
@@ -35,7 +37,7 @@ public abstract class AnsiOutput {
 	private static Boolean ansiCapable;
 
 	private static final String OPERATING_SYSTEM_NAME = System.getProperty("os.name")
-			.toLowerCase();
+			.toLowerCase(Locale.ENGLISH);
 
 	private static final String ENCODE_START = "\033[";
 

spring-boot/src/main/java/org/springframework/boot/bind/PropertySourcesPropertyValues.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -18,6 +18,7 @@ package org.springframework.boot.bind;
 
 import java.util.Collection;
 import java.util.LinkedHashMap;
+import java.util.Locale;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.regex.Pattern;
@@ -184,7 +185,7 @@ public class PropertySourcesPropertyValues implements PropertyValues {
 				// Probably could not convert to Object, weird, but ignorable
 			}
 			if (value == null) {
-				value = source.getProperty(propertyName.toUpperCase());
+				value = source.getProperty(propertyName.toUpperCase(Locale.ENGLISH));
 			}
 			putIfAbsent(propertyName, value, source);
 		}

spring-boot/src/main/java/org/springframework/boot/bind/RelaxedConversionService.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -17,6 +17,7 @@
 package org.springframework.boot.bind;
 
 import java.util.EnumSet;
+import java.util.Locale;
 import java.util.Set;
 
 import org.springframework.core.convert.ConversionFailedException;
@@ -127,7 +128,8 @@ class RelaxedConversionService implements ConversionService {
 				source = source.trim();
 				for (T candidate : (Set<T>) EnumSet.allOf(this.enumType)) {
 					RelaxedNames names = new RelaxedNames(
-							candidate.name().replace('_', '-').toLowerCase());
+							candidate.name().replace('_', '-')
+									.toLowerCase(Locale.ENGLISH));
 					for (String name : names) {
 						if (name.equals(source)) {
 							return candidate;

spring-boot/src/main/java/org/springframework/boot/bind/RelaxedNames.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -18,6 +18,7 @@ package org.springframework.boot.bind;
 
 import java.util.Iterator;
 import java.util.LinkedHashSet;
+import java.util.Locale;
 import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -91,7 +92,7 @@ public final class RelaxedNames implements Iterable<String> {
 
 			@Override
 			public String apply(String value) {
-				return value.isEmpty() ? value : value.toLowerCase();
+				return value.isEmpty() ? value : value.toLowerCase(Locale.ENGLISH);
 			}
 
 		},
@@ -100,7 +101,7 @@ public final class RelaxedNames implements Iterable<String> {
 
 			@Override
 			public String apply(String value) {
-				return value.isEmpty() ? value : value.toUpperCase();
+				return value.isEmpty() ? value : value.toUpperCase(Locale.ENGLISH);
 			}
 
 		};
@@ -225,7 +226,7 @@ public final class RelaxedNames implements Iterable<String> {
 			}
 			StringBuilder builder = new StringBuilder();
 			for (String field : SEPARATED_TO_CAMEL_CASE_PATTERN.split(value)) {
-				field = (caseInsensitive ? field.toLowerCase() : field);
+				field = (caseInsensitive ? field.toLowerCase(Locale.ENGLISH) : field);
 				builder.append(
 						builder.length() == 0 ? field : StringUtils.capitalize(field));
 			}

spring-boot/src/main/java/org/springframework/boot/context/config/AnsiOutputApplicationListener.java

 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.boot.context.config;
 
+import java.util.Locale;
+
 import org.springframework.boot.ansi.AnsiOutput;
 import org.springframework.boot.ansi.AnsiOutput.Enabled;
 import org.springframework.boot.bind.RelaxedPropertyResolver;
@@ -40,7 +42,8 @@ public class AnsiOutputApplicationListener
 				event.getEnvironment(), "spring.output.ansi.");
 		if (resolver.containsProperty("enabled")) {
 			String enabled = resolver.getProperty("enabled");
-			AnsiOutput.setEnabled(Enum.valueOf(Enabled.class, enabled.toUpperCase()));
+			AnsiOutput.setEnabled(Enum.valueOf(Enabled.class,
+					enabled.toUpperCase(Locale.ENGLISH)));
 		}
 
 		if (resolver.containsProperty("console-available")) {

spring-boot/src/main/java/org/springframework/boot/context/embedded/AbstractEmbeddedServletContainerFactory.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -26,6 +26,7 @@ import java.security.CodeSource;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Locale;
 import java.util.jar.JarFile;
 
 import org.apache.commons.logging.Log;
@@ -177,7 +178,7 @@ public abstract class AbstractEmbeddedServletContainerFactory
 			this.logger.debug("Code archive: " + file);
 		}
 		if (file != null && file.exists() && !file.isDirectory()
-				&& file.getName().toLowerCase().endsWith(extension)) {
+				&& file.getName().toLowerCase(Locale.ENGLISH).endsWith(extension)) {
 			return file.getAbsoluteFile();
 		}
 		return null;

spring-boot/src/main/java/org/springframework/boot/env/PropertySourcesLoader.java

 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -20,6 +20,7 @@ import java.io.IOException;
 import java.util.Arrays;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Set;
 
 import org.apache.commons.logging.Log;
@@ -144,9 +145,9 @@ public class PropertySourcesLoader {
 	}
 
 	private boolean canLoadFileExtension(PropertySourceLoader loader, Resource resource) {
-		String filename = resource.getFilename().toLowerCase();
+		String filename = resource.getFilename().toLowerCase(Locale.ENGLISH);
 		for (String extension : loader.getFileExtensions()) {
-			if (filename.endsWith("." + extension.toLowerCase())) {
+			if (filename.endsWith("." + extension.toLowerCase(Locale.ENGLISH))) {
 				return true;
 			}
 		}

spring-boot/src/main/java/org/springframework/boot/jdbc/DatabaseDriver.java

@@ -19,6 +19,7 @@ package org.springframework.boot.jdbc;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.Locale;
 
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
@@ -133,7 +134,7 @@ public enum DatabaseDriver {
 		@Override
 		protected boolean matchProductName(String productName) {
 			return super.matchProductName(productName)
-					|| productName.toLowerCase().startsWith("firebird");
+					|| productName.toLowerCase(Locale.ENGLISH).startsWith("firebird");
 		}
 	},
 
@@ -146,7 +147,7 @@ public enum DatabaseDriver {
 		@Override
 		protected boolean matchProductName(String productName) {
 			return super.matchProductName(productName)
-					|| productName.toLowerCase().startsWith("db2/");
+					|| productName.toLowerCase(Locale.ENGLISH).startsWith("db2/");
 		}
 	},
 
@@ -170,7 +171,7 @@ public enum DatabaseDriver {
 		@Override
 		protected boolean matchProductName(String productName) {
 			return super.matchProductName(productName)
-					|| productName.toLowerCase().contains("as/400");
+					|| productName.toLowerCase(Locale.ENGLISH).contains("as/400");
 		}
 	},
 
@@ -222,7 +223,7 @@ public enum DatabaseDriver {
 	 * @return the identifier
 	 */
 	public String getId() {
-		return name().toLowerCase();
+		return name().toLowerCase(Locale.ENGLISH);
 	}
 
 	protected boolean matchProductName(String productName) {
@@ -230,7 +231,7 @@ public enum DatabaseDriver {
 	}
 
 	protected Collection<String> getUrlPrefixes() {
-		return Collections.singleton(this.name().toLowerCase());
+		return Collections.singleton(this.name().toLowerCase(Locale.ENGLISH));
 	}
 
 	/**
@@ -265,7 +266,8 @@ public enum DatabaseDriver {
 	public static DatabaseDriver fromJdbcUrl(String url) {
 		if (StringUtils.hasLength(url)) {
 			Assert.isTrue(url.startsWith("jdbc"), "URL must start with 'jdbc'");
-			String urlWithoutPrefix = url.substring("jdbc".length()).toLowerCase();
+			String urlWithoutPrefix = url.substring("jdbc".length())
+					.toLowerCase(Locale.ENGLISH);
 			for (DatabaseDriver driver : values()) {
 				for (String urlPrefix : driver.getUrlPrefixes()) {
 					String prefix = ":" + urlPrefix + ":";

spring-boot/src/main/java/org/springframework/boot/logging/LoggingApplicationListener.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -17,6 +17,7 @@
 package org.springframework.boot.logging;
 
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -370,7 +371,7 @@ public class LoggingApplicationListener implements GenericApplicationListener {
 		if ("false".equalsIgnoreCase(level)) {
 			return LogLevel.OFF;
 		}
-		return LogLevel.valueOf(level.toUpperCase());
+		return LogLevel.valueOf(level.toUpperCase(Locale.ENGLISH));
 	}
 
 	private void registerShutdownHookIfNecessary(Environment environment,

spring-boot/src/main/java/org/springframework/boot/system/ApplicationPidFileWriter.java

 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.Locale;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import org.apache.commons.logging.Log;
@@ -250,7 +251,8 @@ public class ApplicationPidFileWriter
 		private final String[] properties;
 
 		SystemProperty(String name) {
-			this.properties = new String[] { name.toUpperCase(), name.toLowerCase() };
+			this.properties = new String[] { name.toUpperCase(Locale.ENGLISH),
+					name.toLowerCase(Locale.ENGLISH) };
 		}
 
 		@Override

spring-boot/src/main/java/org/springframework/boot/system/EmbeddedServerPortFileWriter.java

 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -17,6 +17,7 @@
 package org.springframework.boot.system;
 
 import java.io.File;
+import java.util.Locale;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -113,10 +114,10 @@ public class EmbeddedServerPortFileWriter
 		String extension = StringUtils.getFilenameExtension(this.file.getName());
 		name = name.substring(0, name.length() - extension.length() - 1);
 		if (isUpperCase(name)) {
-			name = name + "-" + contextName.toUpperCase();
+			name = name + "-" + contextName.toUpperCase(Locale.ENGLISH);
 		}
 		else {
-			name = name + "-" + contextName.toLowerCase();
+			name = name + "-" + contextName.toLowerCase(Locale.ENGLISH);
 		}
 		if (StringUtils.hasLength(extension)) {
 			name = name + "." + extension;

spring-boot/src/main/java/org/springframework/boot/web/servlet/MultipartConfigFactory.java

 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.boot.web.servlet;
 
+import java.util.Locale;
+
 import javax.servlet.MultipartConfigElement;
 
 import org.springframework.util.Assert;
@@ -110,7 +112,7 @@ public class MultipartConfigFactory {
 
 	private long parseSize(String size) {
 		Assert.hasLength(size, "Size must not be empty");
-		size = size.toUpperCase();
+		size = size.toUpperCase(Locale.ENGLISH);
 		if (size.endsWith("KB")) {
 			return Long.valueOf(size.substring(0, size.length() - 2)) * 1024;
 		}

spring-boot/src/test/java/org/springframework/boot/system/EmbeddedServerPortFileWriterTests.java

 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -19,6 +19,7 @@ package org.springframework.boot.system;
 import java.io.File;
 import java.io.FileReader;
 import java.util.HashSet;
+import java.util.Locale;
 import java.util.Set;
 
 import org.junit.After;
@@ -103,7 +104,7 @@ public class EmbeddedServerPortFileWriterTests {
 	@Test
 	public void createUpperCaseManagementPortFile() throws Exception {
 		File file = this.temporaryFolder.newFile();
-		file = new File(file.getParentFile(), file.getName().toUpperCase());
+		file = new File(file.getParentFile(), file.getName().toUpperCase(Locale.ENGLISH));
 		EmbeddedServerPortFileWriter listener = new EmbeddedServerPortFileWriter(file);
 		listener.onApplicationEvent(mockEvent("management", 9090));
 		String managementFile = file.getName();