Use Files.writeString() and Files.readString() where possible

See gh-31459

buildSrc/src/main/java/org/springframework/boot/build/bom/bomr/UpgradeApplicator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -17,7 +17,6 @@
 package org.springframework.boot.build.bom.bomr;
 
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
@@ -42,7 +41,7 @@ class UpgradeApplicator {
 	}
 
 	Path apply(Upgrade upgrade) throws IOException {
-		String buildFileContents = new String(Files.readAllBytes(this.buildFile), StandardCharsets.UTF_8);
+		String buildFileContents = Files.readString(this.buildFile);
 		Matcher matcher = Pattern.compile("library\\(\"" + upgrade.getLibrary().getName() + "\", \"(.+)\"\\)")
 				.matcher(buildFileContents);
 		if (!matcher.find()) {
@@ -68,7 +67,7 @@ class UpgradeApplicator {
 
 	private void updateGradleProperties(Upgrade upgrade, String version) throws IOException {
 		String property = version.substring(2, version.length() - 1);
-		String gradlePropertiesContents = new String(Files.readAllBytes(this.gradleProperties), StandardCharsets.UTF_8);
+		String gradlePropertiesContents = Files.readString(this.gradleProperties);
 		String modified = gradlePropertiesContents.replace(
 				property + "=" + upgrade.getLibrary().getVersion().getVersion(), property + "=" + upgrade.getVersion());
 		overwrite(this.gradleProperties, modified);
@@ -82,8 +81,7 @@ class UpgradeApplicator {
 	}
 
 	private void overwrite(Path target, String content) throws IOException {
-		Files.write(target, content.getBytes(StandardCharsets.UTF_8), StandardOpenOption.WRITE,
-				StandardOpenOption.TRUNCATE_EXISTING);
+		Files.writeString(target, content, StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING);
 	}
 
 }

buildSrc/src/main/java/org/springframework/boot/build/mavenplugin/MavenPluginPlugin.java

@@ -309,7 +309,7 @@ public class MavenPluginPlugin implements Plugin<Project> {
 			Path outputLocation = this.outputDir.toPath().resolve(relativePath);
 			try {
 				Files.createDirectories(outputLocation.getParent());
-				Files.write(outputLocation, edit.getFormattedContent().getBytes(StandardCharsets.UTF_8));
+				Files.writeString(outputLocation, edit.getFormattedContent());
 			}
 			catch (Exception ex) {
 				throw new TaskExecutionException(this, ex);

buildSrc/src/test/java/org/springframework/boot/build/bom/bomr/UpgradeApplicatorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -20,7 +20,6 @@ import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.util.Properties;
 
@@ -49,13 +48,13 @@ class UpgradeApplicatorTests {
 	void whenUpgradeIsAppliedToLibraryWithVersionThenBomIsUpdated() throws IOException {
 		File bom = new File(this.temp, "bom.gradle");
 		FileCopyUtils.copy(new File("src/test/resources/bom.gradle"), bom);
-		String originalContents = new String(Files.readAllBytes(bom.toPath()), StandardCharsets.UTF_8);
+		String originalContents = Files.readString(bom.toPath());
 		File gradleProperties = new File(this.temp, "gradle.properties");
 		FileCopyUtils.copy(new File("src/test/resources/gradle.properties"), gradleProperties);
 		new UpgradeApplicator(bom.toPath(), gradleProperties.toPath()).apply(new Upgrade(
 				new Library("ActiveMQ", new LibraryVersion(DependencyVersion.parse("5.15.11"), null), null, null, null),
 				DependencyVersion.parse("5.16")));
-		String bomContents = new String(Files.readAllBytes(bom.toPath()), StandardCharsets.UTF_8);
+		String bomContents = Files.readString(bom.toPath());
 		assertThat(bomContents.length()).isEqualTo(originalContents.length() - 3);
 	}
 
@@ -63,13 +62,13 @@ class UpgradeApplicatorTests {
 	void whenUpgradeIsAppliedToLibraryWithAlignedVersionThenBomIsUpdated() throws IOException {
 		File bom = new File(this.temp, "bom.gradle");
 		FileCopyUtils.copy(new File("src/test/resources/bom.gradle"), bom);
-		String originalContents = new String(Files.readAllBytes(bom.toPath()), StandardCharsets.UTF_8);
+		String originalContents = Files.readString(bom.toPath());
 		File gradleProperties = new File(this.temp, "gradle.properties");
 		FileCopyUtils.copy(new File("src/test/resources/gradle.properties"), gradleProperties);
 		new UpgradeApplicator(bom.toPath(), gradleProperties.toPath()).apply(
 				new Upgrade(new Library("OAuth2 OIDC SDK", new LibraryVersion(DependencyVersion.parse("8.36.1"), null),
 						null, null, null), DependencyVersion.parse("8.36.2")));
-		String bomContents = new String(Files.readAllBytes(bom.toPath()), StandardCharsets.UTF_8);
+		String bomContents = Files.readString(bom.toPath());
 		assertThat(bomContents.length()).isEqualTo(originalContents.length());
 		assertThat(bomContents).contains("version(\"8.36.2\")");
 	}

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/docker/ssl/CertificateParser.java

@@ -18,7 +18,6 @@ package org.springframework.boot.buildpack.platform.docker.ssl;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.security.cert.CertificateException;
@@ -76,7 +75,7 @@ final class CertificateParser {
 
 	private static void readCertificates(Path path, CertificateFactory factory, Consumer<X509Certificate> consumer) {
 		try {
-			String text = readText(path);
+			String text = Files.readString(path);
 			Matcher matcher = PATTERN.matcher(text);
 			while (matcher.find()) {
 				String encodedText = matcher.group(1);
@@ -92,11 +91,6 @@ final class CertificateParser {
 		}
 	}
 
-	private static String readText(Path path) throws IOException {
-		byte[] bytes = Files.readAllBytes(path);
-		return new String(bytes, StandardCharsets.UTF_8);
-	}
-
 	private static byte[] decodeBase64(String content) {
 		byte[] bytes = content.replaceAll("\r", "").replaceAll("\n", "").getBytes();
 		return Base64Utils.decode(bytes);

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/docker/ssl/PrivateKeyParser.java

@@ -18,7 +18,6 @@ package org.springframework.boot.buildpack.platform.docker.ssl;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.security.GeneralSecurityException;
@@ -65,7 +64,7 @@ final class PrivateKeyParser {
 	 */
 	static PrivateKey parse(Path path) {
 		try {
-			String text = readText(path);
+			String text = Files.readString(path);
 			Matcher matcher = PKCS1_PATTERN.matcher(text);
 			if (matcher.find()) {
 				return parsePkcs1(decodeBase64(matcher.group(1)));
@@ -132,11 +131,6 @@ final class PrivateKeyParser {
 		}
 	}
 
-	private static String readText(Path path) throws IOException {
-		byte[] bytes = Files.readAllBytes(path);
-		return new String(bytes, StandardCharsets.UTF_8);
-	}
-
 	private static byte[] decodeBase64(String content) {
 		byte[] contentBytes = content.replaceAll("\r", "").replaceAll("\n", "").getBytes();
 		return Base64Utils.decode(contentBytes);

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/plugin/ResolveMainClassName.java

@@ -18,7 +18,6 @@ package org.springframework.boot.gradle.plugin;
 
 import java.io.File;
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
@@ -122,8 +121,8 @@ public class ResolveMainClassName extends DefaultTask {
 		File outputFile = this.outputFile.getAsFile().get();
 		outputFile.getParentFile().mkdirs();
 		String mainClassName = resolveMainClassName();
-		Files.write(outputFile.toPath(), mainClassName.getBytes(StandardCharsets.UTF_8), StandardOpenOption.WRITE,
-				StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
+		Files.writeString(outputFile.toPath(), mainClassName, StandardOpenOption.WRITE, StandardOpenOption.CREATE,
+				StandardOpenOption.TRUNCATE_EXISTING);
 	}
 
 	private String resolveMainClassName() {
@@ -158,7 +157,7 @@ public class ResolveMainClassName extends DefaultTask {
 			}
 			Path output = file.getAsFile().toPath();
 			try {
-				return new String(Files.readAllBytes(output), StandardCharsets.UTF_8);
+				return Files.readString(output);
 			}
 			catch (IOException ex) {
 				throw new RuntimeException("Failed to read main class name from '" + output + "'");

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/buildinfo/BuildInfoIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -19,7 +19,6 @@ package org.springframework.boot.gradle.tasks.buildinfo;
 import java.io.File;
 import java.io.FileReader;
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
@@ -101,11 +100,11 @@ class BuildInfoIntegrationTests {
 	@TestTemplate
 	void notUpToDateWhenExecutedTwiceWithFixedTimeAndChangedGradlePropertiesProjectVersion() throws IOException {
 		Path gradleProperties = new File(this.gradleBuild.getProjectDir(), "gradle.properties").toPath();
-		Files.write(gradleProperties, "version=0.1.0".getBytes(StandardCharsets.UTF_8), StandardOpenOption.CREATE,
-				StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING);
+		Files.writeString(gradleProperties, "version=0.1.0", StandardOpenOption.CREATE, StandardOpenOption.WRITE,
+				StandardOpenOption.TRUNCATE_EXISTING);
 		assertThat(this.gradleBuild.build("buildInfo").task(":buildInfo").getOutcome()).isEqualTo(TaskOutcome.SUCCESS);
-		Files.write(gradleProperties, "version=0.2.0".getBytes(StandardCharsets.UTF_8), StandardOpenOption.CREATE,
-				StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING);
+		Files.writeString(gradleProperties, "version=0.2.0", StandardOpenOption.CREATE, StandardOpenOption.WRITE,
+				StandardOpenOption.TRUNCATE_EXISTING);
 		assertThat(this.gradleBuild.build("buildInfo").task(":buildInfo").getOutcome()).isEqualTo(TaskOutcome.SUCCESS);
 	}
 

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/AbstractBootArchiveTests.java

@@ -22,11 +22,12 @@ import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
+import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
 import java.nio.file.attribute.PosixFilePermission;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.LinkedHashSet;
@@ -294,11 +295,11 @@ abstract class AbstractBootArchiveTests<T extends Jar & BootArchive> {
 	void customLaunchScriptCanBePrepended() throws IOException {
 		this.task.getMainClass().set("com.example.Main");
 		File customScript = new File(this.temp, "custom.script");
-		Files.write(customScript.toPath(), Arrays.asList("custom script"), StandardOpenOption.CREATE);
+		Files.writeString(customScript.toPath(), "custom script", StandardOpenOption.CREATE);
 		this.task.launchScript((configuration) -> configuration.setScript(customScript));
 		executeTask();
-		assertThat(Files.readAllBytes(this.task.getArchiveFile().get().getAsFile().toPath()))
-				.startsWith("custom script".getBytes());
+		Path path = this.task.getArchiveFile().get().getAsFile().toPath();
+		assertThat(Files.readString(path, StandardCharsets.ISO_8859_1)).startsWith("custom script");
 	}
 
 	@Test
@@ -310,10 +311,11 @@ abstract class AbstractBootArchiveTests<T extends Jar & BootArchive> {
 			configuration.getProperties().put("initInfoDescription", "description");
 		});
 		executeTask();
-		byte[] bytes = Files.readAllBytes(this.task.getArchiveFile().get().getAsFile().toPath());
-		assertThat(bytes).containsSequence("Provides:          provides".getBytes());
-		assertThat(bytes).containsSequence("Short-Description: short description".getBytes());
-		assertThat(bytes).containsSequence("Description:       description".getBytes());
+		Path path = this.task.getArchiveFile().get().getAsFile().toPath();
+		String content = Files.readString(path, StandardCharsets.ISO_8859_1);
+		assertThat(content).containsSequence("Provides:          provides");
+		assertThat(content).containsSequence("Short-Description: short description");
+		assertThat(content).containsSequence("Description:       description");
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/MavenBuild.java

@@ -20,7 +20,6 @@ import java.io.File;
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.PrintWriter;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.FileVisitResult;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -140,12 +139,12 @@ class MavenBuild {
 				@Override
 				public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
 					if (file.toFile().getName().equals("pom.xml")) {
-						String pomXml = new String(Files.readAllBytes(file), StandardCharsets.UTF_8);
+						String pomXml = Files.readString(file);
 						for (Entry<String, String> replacement : MavenBuild.this.pomReplacements.entrySet()) {
 							pomXml = pomXml.replace("@" + replacement.getKey() + "@", replacement.getValue());
 						}
-						Files.write(destination.resolve(source.relativize(file)),
-								pomXml.getBytes(StandardCharsets.UTF_8), StandardOpenOption.CREATE_NEW);
+						Files.writeString(destination.resolve(source.relativize(file)), pomXml,
+								StandardOpenOption.CREATE_NEW);
 					}
 					else {
 						Files.copy(file, destination.resolve(source.relativize(file)),
@@ -155,14 +154,11 @@ class MavenBuild {
 				}
 
 			});
-			String settingsXml = new String(Files.readAllBytes(Paths.get("src", "intTest", "projects", "settings.xml")),
-					StandardCharsets.UTF_8)
-							.replace("@localCentralUrl@",
-									new File("build/int-test-maven-repository").toURI().toURL().toString())
-							.replace("@localRepositoryPath@",
-									new File("build/local-maven-repository").getAbsolutePath());
-			Files.write(destination.resolve("settings.xml"), settingsXml.getBytes(StandardCharsets.UTF_8),
-					StandardOpenOption.CREATE_NEW);
+			String settingsXml = Files.readString(Paths.get("src", "intTest", "projects", "settings.xml"))
+					.replace("@localCentralUrl@",
+							new File("build/int-test-maven-repository").toURI().toURL().toString())
+					.replace("@localRepositoryPath@", new File("build/local-maven-repository").getAbsolutePath());
+			Files.writeString(destination.resolve("settings.xml"), settingsXml, StandardOpenOption.CREATE_NEW);
 			request.setBaseDirectory(this.temp);
 			request.setJavaHome(new File(System.getProperty("java.home")));
 			request.setProperties(this.properties);