Utilize StandardCharsets

Closes gh-10972

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/cloudfoundry/Token.java

@@ -16,7 +16,7 @@
 
 package org.springframework.boot.actuate.autoconfigure.cloudfoundry;
 
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.Map;
 
@@ -33,8 +33,6 @@ import org.springframework.util.StringUtils;
  */
 public class Token {
 
-	private static final Charset UTF_8 = Charset.forName("UTF-8");
-
 	private final String encoded;
 
 	private final String signature;
@@ -63,7 +61,7 @@ public class Token {
 	private Map<String, Object> parseJson(String base64) {
 		try {
 			byte[] bytes = Base64Utils.decodeFromUrlSafeString(base64);
-			return JsonParserFactory.getJsonParser().parseMap(new String(bytes, UTF_8));
+			return JsonParserFactory.getJsonParser().parseMap(new String(bytes, StandardCharsets.UTF_8));
 		}
 		catch (RuntimeException ex) {
 			throw new CloudFoundryAuthorizationException(Reason.INVALID_TOKEN,

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/cloudfoundry/reactive/ReactiveTokenValidatorTests.java

@@ -18,7 +18,7 @@ package org.springframework.boot.actuate.autoconfigure.cloudfoundry.reactive;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.security.KeyFactory;
 import java.security.NoSuchAlgorithmException;
 import java.security.PrivateKey;
@@ -54,8 +54,6 @@ public class ReactiveTokenValidatorTests {
 
 	private static final byte[] DOT = ".".getBytes();
 
-	private static final Charset UTF_8 = Charset.forName("UTF-8");
-
 	@Mock
 	private ReactiveCloudFoundrySecurityService securityService;
 
@@ -226,7 +224,7 @@ public class ReactiveTokenValidatorTests {
 		byte[] crypto = signature.sign();
 		byte[] token = dotConcat(Base64Utils.encodeUrlSafe(header),
 				Base64Utils.encodeUrlSafe(claims), Base64Utils.encodeUrlSafe(crypto));
-		return new String(token, UTF_8);
+		return new String(token, StandardCharsets.UTF_8);
 	}
 
 	private PrivateKey getPrivateKey()

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/cloudfoundry/servlet/TokenValidatorTests.java

@@ -18,7 +18,7 @@ package org.springframework.boot.actuate.autoconfigure.cloudfoundry.servlet;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.security.KeyFactory;
 import java.security.NoSuchAlgorithmException;
 import java.security.PrivateKey;
@@ -56,8 +56,6 @@ public class TokenValidatorTests {
 
 	private static final byte[] DOT = ".".getBytes();
 
-	private static final Charset UTF_8 = Charset.forName("UTF-8");
-
 	@Rule
 	public ExpectedException thrown = ExpectedException.none();
 
@@ -216,7 +214,7 @@ public class TokenValidatorTests {
 		byte[] crypto = signature.sign();
 		byte[] token = dotConcat(Base64Utils.encodeUrlSafe(header),
 				Base64Utils.encodeUrlSafe(claims), Base64Utils.encodeUrlSafe(crypto));
-		return new String(token, UTF_8);
+		return new String(token, StandardCharsets.UTF_8);
 	}
 
 	private PrivateKey getPrivateKey()

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jersey/JerseyAutoConfigurationServletContainerTests.java

@@ -16,7 +16,7 @@
 
 package org.springframework.boot.autoconfigure.jersey;
 
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 
 import javax.ws.rs.GET;
 import javax.ws.rs.Path;
@@ -105,7 +105,7 @@ public class JerseyAutoConfigurationServletContainerTests {
 					jerseyServlet.setServlet(new ServletContainer());
 					jerseyServlet.setOverridable(false);
 					context.addChild(jerseyServlet);
-					String pattern = UDecoder.URLDecode("/*", Charset.forName("UTF-8"));
+					String pattern = UDecoder.URLDecode("/*", StandardCharsets.UTF_8);
 					context.addServletMappingDecoded(pattern, servletName);
 				}
 

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/ServerPropertiesTests.java

@@ -17,7 +17,7 @@
 package org.springframework.boot.autoconfigure.web;
 
 import java.net.InetAddress;
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
@@ -141,7 +141,7 @@ public class ServerPropertiesTests {
 	public void testCustomizeUriEncoding() throws Exception {
 		bind("server.tomcat.uri-encoding", "US-ASCII");
 		assertThat(this.properties.getTomcat().getUriEncoding())
-				.isEqualTo(Charset.forName("US-ASCII"));
+				.isEqualTo(StandardCharsets.US_ASCII);
 	}
 
 	@Test

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/servlet/HttpEncodingAutoConfigurationTests.java

@@ -16,7 +16,7 @@
 
 package org.springframework.boot.autoconfigure.web.servlet;
 
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;
@@ -160,10 +160,10 @@ public class HttpEncodingAutoConfigurationTests {
 				.getLocaleCharsetMappings().size()).isEqualTo(2);
 		assertThat(this.context.getBean(MockServletWebServerFactory.class)
 				.getLocaleCharsetMappings().get(Locale.ENGLISH))
-						.isEqualTo(Charset.forName("UTF-8"));
+						.isEqualTo(StandardCharsets.UTF_8);
 		assertThat(this.context.getBean(MockServletWebServerFactory.class)
 				.getLocaleCharsetMappings().get(Locale.FRANCE))
-						.isEqualTo(Charset.forName("UTF-8"));
+						.isEqualTo(StandardCharsets.UTF_8);
 	}
 
 	@SuppressWarnings({ "unchecked", "rawtypes" })

spring-boot-project/spring-boot-cli/src/main/java/org/springframework/boot/cli/command/init/InitializrService.java

@@ -19,6 +19,7 @@ package org.springframework.boot.cli.command.init;
 import java.io.IOException;
 import java.net.URI;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 
 import org.apache.http.Header;
 import org.apache.http.HttpEntity;
@@ -47,8 +48,6 @@ class InitializrService {
 
 	private static final String FILENAME_HEADER_PREFIX = "filename=\"";
 
-	private static final Charset UTF_8 = Charset.forName("UTF-8");
-
 	/**
 	 * Accept header to use to retrieve the json meta-data.
 	 */
@@ -241,7 +240,7 @@ class InitializrService {
 	private String getContent(HttpEntity entity) throws IOException {
 		ContentType contentType = ContentType.getOrDefault(entity);
 		Charset charset = contentType.getCharset();
-		charset = (charset != null ? charset : UTF_8);
+		charset = (charset != null ? charset : StandardCharsets.UTF_8);
 		byte[] content = FileCopyUtils.copyToByteArray(entity.getContent());
 		return new String(content, charset);
 	}

spring-boot-project/spring-boot-cli/src/main/java/org/springframework/boot/cli/command/install/GroovyGrabDependencyResolver.java

@@ -22,6 +22,7 @@ import java.io.IOException;
 import java.io.OutputStreamWriter;
 import java.net.URISyntaxException;
 import java.net.URL;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -70,7 +71,7 @@ class GroovyGrabDependencyResolver implements DependencyResolver {
 		File file = File.createTempFile("SpringCLIDependency", ".groovy");
 		file.deleteOnExit();
 		try (OutputStreamWriter stream = new OutputStreamWriter(
-				new FileOutputStream(file), "UTF-8")) {
+				new FileOutputStream(file), StandardCharsets.UTF_8)) {
 			for (String artifactIdentifier : artifactIdentifiers) {
 				stream.write("@Grab('" + artifactIdentifier + "')");
 			}

spring-boot-project/spring-boot-cli/src/test/java/org/springframework/boot/cli/command/init/InitializrServiceMetadataTests.java

@@ -18,7 +18,7 @@ package org.springframework.boot.cli.command.init;
 
 import java.io.IOException;
 import java.io.InputStream;
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 
 import org.json.JSONException;
 import org.json.JSONObject;
@@ -31,7 +31,7 @@ import org.springframework.util.StreamUtils;
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
- * Tests for {@link InitializrServiceMetadata}
+ * Tests for {@link InitializrServiceMetadata}.
  *
  * @author Stephane Nicoll
  */
@@ -94,7 +94,7 @@ public class InitializrServiceMetadataTests {
 				"metadata/service-metadata-" + version + ".json");
 		try (InputStream stream = resource.getInputStream()) {
 			return new JSONObject(
-					StreamUtils.copyToString(stream, Charset.forName("UTF-8")));
+					StreamUtils.copyToString(stream, StandardCharsets.UTF_8));
 		}
 	}
 

spring-boot-project/spring-boot-cli/src/test/java/org/springframework/boot/cli/command/init/ProjectGenerationRequestTests.java

@@ -19,7 +19,7 @@ package org.springframework.boot.cli.command.init;
 import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.Collections;
 import java.util.Map;
 
@@ -36,7 +36,7 @@ import org.springframework.util.StreamUtils;
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
- * Tests for {@link ProjectGenerationRequest}
+ * Tests for {@link ProjectGenerationRequest}.
  *
  * @author Stephane Nicoll
  * @author Eddú Meléndez
@@ -253,7 +253,7 @@ public class ProjectGenerationRequestTests {
 			Resource resource = new ClassPathResource(
 					"metadata/service-metadata-" + version + ".json");
 			String content = StreamUtils.copyToString(resource.getInputStream(),
-					Charset.forName("UTF-8"));
+					StandardCharsets.UTF_8);
 			JSONObject json = new JSONObject(content);
 			return new InitializrServiceMetadata(json);
 		}

spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/restart/classloader/RestartClassLoaderTests.java

@@ -22,7 +22,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
 import java.net.URLClassLoader;
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.List;
@@ -54,8 +54,6 @@ public class RestartClassLoaderTests {
 
 	private static final String PACKAGE_PATH = PACKAGE.replace('.', '/');
 
-	private static final Charset UTF_8 = Charset.forName("UTF-8");
-
 	@Rule
 	public ExpectedException thrown = ExpectedException.none();
 
@@ -89,7 +87,7 @@ public class RestartClassLoaderTests {
 		StreamUtils.copy(getClass().getResourceAsStream("Sample.class"), jarOutputStream);
 		jarOutputStream.closeEntry();
 		jarOutputStream.putNextEntry(new ZipEntry(PACKAGE_PATH + "/Sample.txt"));
-		StreamUtils.copy("fromchild", UTF_8, jarOutputStream);
+		StreamUtils.copy("fromchild", StandardCharsets.UTF_8, jarOutputStream);
 		jarOutputStream.closeEntry();
 		jarOutputStream.close();
 		return file;

spring-boot-project/spring-boot-test-autoconfigure/src/test/java/org/springframework/boot/test/autoconfigure/data/redis/DataRedisTestIntegrationTests.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.test.autoconfigure.data.redis;
 
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 
 import org.junit.Rule;
 import org.junit.Test;
@@ -57,7 +58,7 @@ public class DataRedisTestIntegrationTests {
 	@Autowired
 	private ApplicationContext applicationContext;
 
-	private static final Charset CHARSET = Charset.forName("UTF-8");
+	private static final Charset CHARSET = StandardCharsets.UTF_8;
 
 	@Test
 	public void testRepository() {

spring-boot-project/spring-boot-test-autoconfigure/src/test/java/org/springframework/boot/test/autoconfigure/data/redis/ExampleService.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.test.autoconfigure.data.redis;
 
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 
 import org.springframework.data.redis.connection.RedisConnection;
 import org.springframework.data.redis.core.RedisOperations;
@@ -30,7 +31,7 @@ import org.springframework.stereotype.Service;
 @Service
 public class ExampleService {
 
-	private static final Charset CHARSET = Charset.forName("UTF-8");
+	private static final Charset CHARSET = StandardCharsets.UTF_8;
 
 	private RedisOperations<Object, Object> operations;
 

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/json/JsonLoader.java

@@ -23,6 +23,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
@@ -42,7 +43,7 @@ class JsonLoader {
 
 	JsonLoader(Class<?> resourceLoadClass, Charset charset) {
 		this.resourceLoadClass = resourceLoadClass;
-		this.charset = charset == null ? Charset.forName("UTF-8") : charset;
+		this.charset = charset == null ? StandardCharsets.UTF_8 : charset;
 	}
 
 	Class<?> getResourceLoadClass() {

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

@@ -19,6 +19,7 @@ package org.springframework.boot.configurationmetadata;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -32,12 +33,7 @@ import java.util.Map;
  */
 public final class ConfigurationMetadataRepositoryJsonBuilder {
 
-	/**
-	 * UTF-8 Charset.
-	 */
-	public static final Charset UTF_8 = Charset.forName("UTF-8");
-
-	private Charset defaultCharset = UTF_8;
+	private Charset defaultCharset = StandardCharsets.UTF_8;
 
 	private final JsonReader reader = new JsonReader();
 
@@ -159,7 +155,7 @@ public final class ConfigurationMetadataRepositoryJsonBuilder {
 	}
 
 	/**
-	 * Create a new builder instance using {@link #UTF_8} as the default charset and the
+	 * Create a new builder instance using {@link StandardCharsets#UTF_8} as the default charset and the
 	 * specified json resource.
 	 * @param inputStreams the source input streams
 	 * @return a new {@link ConfigurationMetadataRepositoryJsonBuilder} instance.
@@ -175,11 +171,11 @@ public final class ConfigurationMetadataRepositoryJsonBuilder {
 	}
 
 	/**
-	 * Create a new builder instance using {@link #UTF_8} as the default charset.
+	 * Create a new builder instance using {@link StandardCharsets#UTF_8} as the default charset.
 	 * @return a new {@link ConfigurationMetadataRepositoryJsonBuilder} instance.
 	 */
 	public static ConfigurationMetadataRepositoryJsonBuilder create() {
-		return create(UTF_8);
+		return create(StandardCharsets.UTF_8);
 	}
 
 	/**

spring-boot-project/spring-boot-tools/spring-boot-configuration-metadata/src/test/java/org/springframework/boot/configurationmetadata/JsonReaderTests.java

@@ -18,6 +18,7 @@ package org.springframework.boot.configurationmetadata;
 
 import java.io.IOException;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 
 import org.hamcrest.CoreMatchers;
@@ -27,13 +28,13 @@ import org.junit.Test;
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
- * Tests for {@link JsonReader}
+ * Tests for {@link JsonReader}.
  *
  * @author Stephane Nicoll
  */
 public class JsonReaderTests extends AbstractConfigurationMetadataTests {
 
-	private static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");
+	private static final Charset DEFAULT_CHARSET = StandardCharsets.UTF_8;
 
 	private final JsonReader reader = new JsonReader();
 

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

@@ -20,7 +20,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -41,8 +41,6 @@ import org.springframework.boot.configurationprocessor.metadata.ItemMetadata.Ite
  */
 public class JsonMarshaller {
 
-	private static final Charset UTF_8 = Charset.forName("UTF-8");
-
 	private static final int BUFFER_SIZE = 4098;
 
 	public void write(ConfigurationMetadata metadata, OutputStream outputStream)
@@ -53,7 +51,7 @@ public class JsonMarshaller {
 			object.put("groups", converter.toJsonArray(metadata, ItemType.GROUP));
 			object.put("properties", converter.toJsonArray(metadata, ItemType.PROPERTY));
 			object.put("hints", converter.toJsonArray(metadata.getHints()));
-			outputStream.write(object.toString(2).getBytes(UTF_8));
+			outputStream.write(object.toString(2).getBytes(StandardCharsets.UTF_8));
 		}
 		catch (Exception ex) {
 			if (ex instanceof IOException) {
@@ -170,7 +168,7 @@ public class JsonMarshaller {
 
 	private String toString(InputStream inputStream) throws IOException {
 		StringBuilder out = new StringBuilder();
-		InputStreamReader reader = new InputStreamReader(inputStream, UTF_8);
+		InputStreamReader reader = new InputStreamReader(inputStream, StandardCharsets.UTF_8);
 		char[] buffer = new char[BUFFER_SIZE];
 		int bytesRead;
 		while ((bytesRead = reader.read(buffer)) != -1) {

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

@@ -22,7 +22,7 @@ import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
@@ -42,8 +42,6 @@ import java.util.regex.Pattern;
  */
 public class DefaultLaunchScript implements LaunchScript {
 
-	private static final Charset UTF_8 = Charset.forName("UTF-8");
-
 	private static final int BUFFER_SIZE = 4096;
 
 	private static final Pattern PLACEHOLDER_PATTERN = Pattern
@@ -76,7 +74,7 @@ public class DefaultLaunchScript implements LaunchScript {
 		try {
 			ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
 			copy(inputStream, outputStream);
-			return new String(outputStream.toByteArray(), UTF_8);
+			return new String(outputStream.toByteArray(), StandardCharsets.UTF_8);
 		}
 		finally {
 			inputStream.close();
@@ -129,7 +127,7 @@ public class DefaultLaunchScript implements LaunchScript {
 
 	@Override
 	public byte[] toByteArray() {
-		return this.content.getBytes(UTF_8);
+		return this.content.getBytes(StandardCharsets.UTF_8);
 	}
 
 }

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/jar/AsciiBytes.java

@@ -16,7 +16,7 @@
 
 package org.springframework.boot.loader.jar;
 
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 
 /**
  * Simple wrapper around a byte array that represents an ASCII. Used for performance
@@ -27,8 +27,6 @@ import java.nio.charset.Charset;
  */
 final class AsciiBytes {
 
-	private static final Charset UTF_8 = Charset.forName("UTF-8");
-
 	private final byte[] bytes;
 
 	private final int offset;
@@ -44,7 +42,7 @@ final class AsciiBytes {
 	 * @param string the source string
 	 */
 	AsciiBytes(String string) {
-		this(string.getBytes(UTF_8));
+		this(string.getBytes(StandardCharsets.UTF_8));
 		this.string = string;
 	}
 
@@ -124,7 +122,7 @@ final class AsciiBytes {
 		if (string == null || string.isEmpty()) {
 			return this;
 		}
-		return append(string.getBytes(UTF_8));
+		return append(string.getBytes(StandardCharsets.UTF_8));
 	}
 
 	public AsciiBytes append(AsciiBytes asciiBytes) {
@@ -147,7 +145,7 @@ final class AsciiBytes {
 	@Override
 	public String toString() {
 		if (this.string == null) {
-			this.string = new String(this.bytes, this.offset, this.length, UTF_8);
+			this.string = new String(this.bytes, this.offset, this.length, StandardCharsets.UTF_8);
 		}
 		return this.string;
 	}
@@ -215,7 +213,7 @@ final class AsciiBytes {
 	}
 
 	static String toString(byte[] bytes) {
-		return new String(bytes, UTF_8);
+		return new String(bytes, StandardCharsets.UTF_8);
 	}
 
 	public static int hashCode(String string) {

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/ResourceBanner.java

@@ -18,6 +18,7 @@ package org.springframework.boot;
 
 import java.io.PrintStream;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -62,7 +63,7 @@ public class ResourceBanner implements Banner {
 		try {
 			String banner = StreamUtils.copyToString(this.resource.getInputStream(),
 					environment.getProperty("banner.charset", Charset.class,
-							Charset.forName("UTF-8")));
+							StandardCharsets.UTF_8));
 
 			for (PropertyResolver resolver : getPropertyResolvers(environment,
 					sourceClass)) {

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/env/OriginTrackedPropertiesLoader.java

@@ -20,6 +20,7 @@ import java.io.Closeable;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.LineNumberReader;
+import java.nio.charset.StandardCharsets;
 import java.util.LinkedHashMap;
 import java.util.Map;
 
@@ -155,7 +156,7 @@ class OriginTrackedPropertiesLoader {
 
 		CharacterReader(Resource resource) throws IOException {
 			this.reader = new LineNumberReader(
-					new InputStreamReader(resource.getInputStream(), "8859_1"));
+					new InputStreamReader(resource.getInputStream(), StandardCharsets.ISO_8859_1));
 		}
 
 		@Override

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/logback/DefaultLogbackConfiguration.java

@@ -17,7 +17,7 @@
 package org.springframework.boot.logging.logback;
 
 import java.lang.reflect.Method;
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 
 import ch.qos.logback.classic.Level;
 import ch.qos.logback.classic.encoder.PatternLayoutEncoder;
@@ -60,8 +60,6 @@ class DefaultLogbackConfiguration {
 
 	private static final String MAX_FILE_SIZE = "10MB";
 
-	private static final Charset UTF8 = Charset.forName("UTF-8");
-
 	private final PropertyResolver patterns;
 
 	private final LogFile logFile;
@@ -125,7 +123,7 @@ class DefaultLogbackConfiguration {
 		String logPattern = this.patterns.getProperty("logging.pattern.console",
 				CONSOLE_LOG_PATTERN);
 		encoder.setPattern(OptionHelper.substVars(logPattern, config.getContext()));
-		encoder.setCharset(UTF8);
+		encoder.setCharset(StandardCharsets.UTF_8);
 		config.start(encoder);
 		appender.setEncoder(encoder);
 		config.appender("CONSOLE", appender);

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/tomcat/TomcatServletWebServerFactory.java

@@ -21,6 +21,7 @@ import java.io.InputStream;
 import java.lang.reflect.Method;
 import java.net.URL;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -97,7 +98,7 @@ import org.springframework.util.StringUtils;
 public class TomcatServletWebServerFactory extends AbstractServletWebServerFactory
 		implements ResourceLoaderAware {
 
-	private static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");
+	private static final Charset DEFAULT_CHARSET = StandardCharsets.UTF_8;
 
 	private static final Set<Class<?>> NO_CLASSES = Collections.emptySet();
 

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/embedded/tomcat/TomcatServletWebServerFactoryTests.java

@@ -19,6 +19,7 @@ package org.springframework.boot.web.embedded.tomcat;
 import java.io.File;
 import java.io.IOException;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.Locale;
 import java.util.Map;
@@ -248,7 +249,7 @@ public class TomcatServletWebServerFactoryTests
 	@Test
 	public void uriEncoding() throws Exception {
 		TomcatServletWebServerFactory factory = getFactory();
-		factory.setUriEncoding(Charset.forName("US-ASCII"));
+		factory.setUriEncoding(StandardCharsets.US_ASCII);
 		Tomcat tomcat = getTomcat(factory);
 		Connector connector = ((TomcatWebServer) this.webServer).getServiceConnectors()
 				.get(tomcat.getService())[0];
@@ -364,8 +365,8 @@ public class TomcatServletWebServerFactoryTests
 		TomcatServletWebServerFactory factory = getFactory();
 		this.webServer = factory.getWebServer();
 		// override defaults, see org.apache.catalina.util.CharsetMapperDefault.properties
-		assertThat(getCharset(Locale.ENGLISH).toString()).isEqualTo("UTF-8");
-		assertThat(getCharset(Locale.FRENCH).toString()).isEqualTo("UTF-8");
+		assertThat(getCharset(Locale.ENGLISH)).isEqualTo(StandardCharsets.UTF_8);
+		assertThat(getCharset(Locale.FRENCH)).isEqualTo(StandardCharsets.UTF_8);
 	}
 
 	@Test

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/context/ServletWebServerMvcIntegrationTests.java

@@ -17,7 +17,7 @@
 package org.springframework.boot.web.servlet.context;
 
 import java.net.URI;
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 
 import org.junit.After;
 import org.junit.Test;
@@ -103,7 +103,7 @@ public class ServletWebServerMvcIntegrationTests {
 				HttpMethod.GET);
 		try (ClientHttpResponse response = request.execute()) {
 			String actual = StreamUtils.copyToString(response.getBody(),
-					Charset.forName("UTF-8"));
+					StandardCharsets.UTF_8);
 			assertThat(actual).isEqualTo("Hello World");
 		}
 	}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/server/AbstractServletWebServerFactoryTests.java

@@ -29,6 +29,7 @@ import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.security.KeyStore;
 import java.security.KeyStoreException;
 import java.security.NoSuchAlgorithmException;
@@ -911,10 +912,10 @@ public abstract class AbstractServletWebServerFactoryTests {
 	public void localeCharsetMappingsAreConfigured() throws Exception {
 		AbstractServletWebServerFactory factory = getFactory();
 		Map<Locale, Charset> mappings = new HashMap<>();
-		mappings.put(Locale.GERMAN, Charset.forName("UTF-8"));
+		mappings.put(Locale.GERMAN, StandardCharsets.UTF_8);
 		factory.setLocaleCharsetMappings(mappings);
 		this.webServer = factory.getWebServer();
-		assertThat(getCharset(Locale.GERMAN).toString()).isEqualTo("UTF-8");
+		assertThat(getCharset(Locale.GERMAN)).isEqualTo(StandardCharsets.UTF_8);
 		assertThat(getCharset(Locale.ITALIAN)).isNull();
 	}
 
@@ -1063,7 +1064,7 @@ public abstract class AbstractServletWebServerFactoryTests {
 	protected String getResponse(String url, HttpMethod method, String... headers)
 			throws IOException, URISyntaxException {
 		try (ClientHttpResponse response = getClientResponse(url, method, headers)) {
-			return StreamUtils.copyToString(response.getBody(), Charset.forName("UTF-8"));
+			return StreamUtils.copyToString(response.getBody(), StandardCharsets.UTF_8);
 		}
 	}
 
@@ -1078,7 +1079,7 @@ public abstract class AbstractServletWebServerFactoryTests {
 					throws IOException, URISyntaxException {
 		try (ClientHttpResponse response = getClientResponse(url, method, requestFactory,
 				headers)) {
-			return StreamUtils.copyToString(response.getBody(), Charset.forName("UTF-8"));
+			return StreamUtils.copyToString(response.getBody(), StandardCharsets.UTF_8);
 		}
 	}
 

spring-boot-samples/spring-boot-sample-jetty/src/test/java/sample/jetty/SampleJettyApplicationTests.java

@@ -17,7 +17,7 @@
 package sample.jetty;
 
 import java.io.ByteArrayInputStream;
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.zip.GZIPInputStream;
 
 import org.junit.Test;
@@ -69,7 +69,7 @@ public class SampleJettyApplicationTests {
 		assertThat(entity.getStatusCode()).isEqualTo(HttpStatus.OK);
 		try (GZIPInputStream inflater = new GZIPInputStream(
 				new ByteArrayInputStream(entity.getBody()))) {
-			assertThat(StreamUtils.copyToString(inflater, Charset.forName("UTF-8")))
+			assertThat(StreamUtils.copyToString(inflater, StandardCharsets.UTF_8))
 					.isEqualTo("Hello World");
 		}
 	}

spring-boot-samples/spring-boot-sample-tomcat/src/test/java/sample/tomcat/SampleTomcatApplicationTests.java

@@ -18,6 +18,7 @@ package sample.tomcat;
 
 import java.io.ByteArrayInputStream;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.zip.GZIPInputStream;
 
 import org.apache.coyote.AbstractProtocol;
@@ -77,7 +78,7 @@ public class SampleTomcatApplicationTests {
 		assertThat(entity.getStatusCode()).isEqualTo(HttpStatus.OK);
 		try (GZIPInputStream inflater = new GZIPInputStream(
 				new ByteArrayInputStream(entity.getBody()))) {
-			assertThat(StreamUtils.copyToString(inflater, Charset.forName("UTF-8")))
+			assertThat(StreamUtils.copyToString(inflater, StandardCharsets.UTF_8))
 					.isEqualTo("Hello World");
 		}
 	}

spring-boot-samples/spring-boot-sample-undertow/src/test/java/sample/undertow/SampleUndertowApplicationTests.java

@@ -18,6 +18,7 @@ package sample.undertow;
 
 import java.io.ByteArrayInputStream;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.zip.GZIPInputStream;
 
 import org.junit.Test;
@@ -73,7 +74,7 @@ public class SampleUndertowApplicationTests {
 
 		try (GZIPInputStream inflater = new GZIPInputStream(
 				new ByteArrayInputStream(entity.getBody()))) {
-			assertThat(StreamUtils.copyToString(inflater, Charset.forName("UTF-8")))
+			assertThat(StreamUtils.copyToString(inflater, StandardCharsets.UTF_8))
 					.isEqualTo("Hello World");
 		}
 	}

spring-boot-tests/spring-boot-integration-tests/spring-boot-security-tests/spring-boot-security-test-web-helloworld/src/test/java/sample/HelloWebSecurityApplicationTests.java

@@ -16,6 +16,7 @@
 
 package sample;
 
+import java.nio.charset.StandardCharsets;
 import java.util.Base64;
 
 import javax.servlet.http.HttpServletResponse;
@@ -67,7 +68,7 @@ public class HelloWebSecurityApplicationTests {
 	public void userAuthenticates() throws Exception {
 		this.request.addHeader("Accept", "application/json");
 		this.request.addHeader("Authorization", "Basic " + new String(
-				Base64.getEncoder().encode("user:password".getBytes("UTF-8"))));
+				Base64.getEncoder().encode("user:password".getBytes(StandardCharsets.UTF_8))));
 
 		this.springSecurityFilterChain.doFilter(this.request, this.response, this.chain);