Merge pull request #44353 from nosan

* pr/44353:
  Polish "Use Console charset for console logging when available"
  Use Console charset for console logging when available

Closes gh-44353

Author: mhalbritter

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

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.logging;
 
+import java.io.Console;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.util.function.BiConsumer;
@@ -91,8 +92,8 @@ public LoggingSystemProperties(Environment environment, Function<String, String>
 		this.setter = (setter != null) ? setter : systemPropertySetter;
 	}
 
-	protected Charset getDefaultCharset() {
-		return StandardCharsets.UTF_8;
+	protected Console getConsole() {
+		return System.console();
 	}
 
 	public final void apply() {
@@ -116,12 +117,14 @@ private PropertyResolver getPropertyResolver() {
 	}
 
 	protected void apply(LogFile logFile, PropertyResolver resolver) {
-		String defaultCharsetName = getDefaultCharset().name();
+		Charset defaultCharset = getDefaultCharset();
+		Charset consoleCharset = (defaultCharset != null) ? defaultCharset : getDefaultConsoleCharset();
+		Charset fileCharset = (defaultCharset != null) ? defaultCharset : getDefaultFileCharset();
 		setSystemProperty(LoggingSystemProperty.APPLICATION_NAME, resolver);
 		setSystemProperty(LoggingSystemProperty.APPLICATION_GROUP, resolver);
 		setSystemProperty(LoggingSystemProperty.PID, new ApplicationPid().toString());
-		setSystemProperty(LoggingSystemProperty.CONSOLE_CHARSET, resolver, defaultCharsetName);
-		setSystemProperty(LoggingSystemProperty.FILE_CHARSET, resolver, defaultCharsetName);
+		setSystemProperty(LoggingSystemProperty.CONSOLE_CHARSET, resolver, consoleCharset.name());
+		setSystemProperty(LoggingSystemProperty.FILE_CHARSET, resolver, fileCharset.name());
 		setSystemProperty(LoggingSystemProperty.CONSOLE_THRESHOLD, resolver, this::thresholdMapper);
 		setSystemProperty(LoggingSystemProperty.FILE_THRESHOLD, resolver, this::thresholdMapper);
 		setSystemProperty(LoggingSystemProperty.EXCEPTION_CONVERSION_WORD, resolver);
@@ -137,6 +140,34 @@ protected void apply(LogFile logFile, PropertyResolver resolver) {
 		}
 	}
 
+	/**
+	 * Returns the default charset.
+	 * @return the default charset
+	 * @deprecated since 3.5.0 for removal in 3.7.0 in favor of
+	 * {@link #getDefaultConsoleCharset()} and {@link #getDefaultFileCharset()}.
+	 */
+	@Deprecated(since = "3.5.0", forRemoval = true)
+	protected Charset getDefaultCharset() {
+		return null;
+	}
+
+	/**
+	 * Returns the default console charset.
+	 * @return returns the default console charset
+	 */
+	protected Charset getDefaultConsoleCharset() {
+		Console console = getConsole();
+		return (console != null) ? console.charset() : Charset.defaultCharset();
+	}
+
+	/**
+	 * Returns the default file charset.
+	 * @return returns the default file charset
+	 */
+	protected Charset getDefaultFileCharset() {
+		return StandardCharsets.UTF_8;
+	}
+
 	private void setSystemProperty(LoggingSystemProperty property, PropertyResolver resolver) {
 		setSystemProperty(property, resolver, Function.identity());
 	}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2024 the original author or authors.
+ * Copyright 2012-2025 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.logging.logback;
 
+import java.io.Console;
 import java.nio.charset.Charset;
 import java.util.function.BiConsumer;
 import java.util.function.Function;
@@ -71,7 +72,12 @@ public LogbackLoggingSystemProperties(Environment environment, Function<String,
 	}
 
 	@Override
-	protected Charset getDefaultCharset() {
+	protected Console getConsole() {
+		return super.getConsole();
+	}
+
+	@Override
+	protected Charset getDefaultFileCharset() {
 		return Charset.defaultCharset();
 	}
 

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/logging/LoggingSystemPropertiesTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2024 the original author or authors.
+ * Copyright 2012-2025 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 +16,9 @@
 
 package org.springframework.boot.logging;
 
+import java.io.Console;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Map;
@@ -31,6 +34,9 @@
 import org.springframework.mock.env.MockEnvironment;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
 
 /**
  * Tests for {@link LoggingSystemProperties}.
@@ -72,9 +78,22 @@ void consoleLogPatternIsSet() {
 	}
 
 	@Test
-	void consoleCharsetWhenNoPropertyUsesUtf8() {
-		new LoggingSystemProperties(new MockEnvironment()).apply(null);
-		assertThat(getSystemProperty(LoggingSystemProperty.CONSOLE_CHARSET)).isEqualTo("UTF-8");
+	void consoleCharsetWhenNoPropertyUsesCharsetDefault() {
+		LoggingSystemProperties loggingSystemProperties = spy(new LoggingSystemProperties(new MockEnvironment()));
+		given(loggingSystemProperties.getConsole()).willReturn(null);
+		loggingSystemProperties.apply(null);
+		assertThat(getSystemProperty(LoggingSystemProperty.CONSOLE_CHARSET)).isEqualTo(Charset.defaultCharset().name());
+	}
+
+	@Test
+	void consoleCharsetWhenNoPropertyUsesSystemConsoleCharsetWhenAvailable() {
+		LoggingSystemProperties loggingSystemProperties = spy(new LoggingSystemProperties(new MockEnvironment()));
+		Console console = mock(Console.class);
+		given(console.charset()).willReturn(StandardCharsets.UTF_16BE);
+		given(loggingSystemProperties.getConsole()).willReturn(console);
+		loggingSystemProperties.apply(null);
+		assertThat(getSystemProperty(LoggingSystemProperty.CONSOLE_CHARSET))
+			.isEqualTo(StandardCharsets.UTF_16BE.name());
 	}
 
 	@Test

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/logging/logback/LogbackLoggingSystemPropertiesTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -16,7 +16,9 @@
 
 package org.springframework.boot.logging.logback;
 
+import java.io.Console;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.HashSet;
 import java.util.Set;
 
@@ -31,6 +33,9 @@
 import org.springframework.mock.env.MockEnvironment;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
 
 /**
  * Tests for {@link LogbackLoggingSystemProperties}.
@@ -102,11 +107,29 @@ void applySetsLogbackSystemPropertiesFromDeprecated() {
 
 	@Test
 	void consoleCharsetWhenNoPropertyUsesDefault() {
-		new LoggingSystemProperties(new MockEnvironment()).apply(null);
+		LogbackLoggingSystemProperties logbackLoggingSystemProperties = spy(
+				new LogbackLoggingSystemProperties(new MockEnvironment(), null, null));
+		given(logbackLoggingSystemProperties.getConsole()).willReturn(null);
+
+		logbackLoggingSystemProperties.apply(null);
 		assertThat(System.getProperty(LoggingSystemProperty.CONSOLE_CHARSET.getEnvironmentVariableName()))
 			.isEqualTo(Charset.defaultCharset().name());
 	}
 
+	@Test
+	void consoleCharsetWhenNoPropertyUsesSystemConsoleCharsetWhenAvailable() {
+		LogbackLoggingSystemProperties logbackLoggingSystemProperties = spy(
+				new LogbackLoggingSystemProperties(new MockEnvironment(), null, null));
+
+		Console console = mock(Console.class);
+		given(console.charset()).willReturn(StandardCharsets.UTF_16BE);
+		given(logbackLoggingSystemProperties.getConsole()).willReturn(console);
+
+		logbackLoggingSystemProperties.apply(null);
+		assertThat(System.getProperty(LoggingSystemProperty.CONSOLE_CHARSET.getEnvironmentVariableName()))
+			.isEqualTo(StandardCharsets.UTF_16BE.name());
+	}
+
 	@Test
 	void fileCharsetWhenNoPropertyUsesDefault() {
 		new LoggingSystemProperties(new MockEnvironment()).apply(null);