Add more styling support to the Logback and Log4j2 color converters

- Add REVERSE (ANSI code 7) to AnsiStyle enum
- Expand ColorConverter ELEMENTS map to include all AnsiStyle values
  (bold, italic, underline, normal, faint, reverse) and all AnsiBackground
  colors with the bg_ prefix (bg_red, bg_bright_green, etc.)
- Update tests for both logback and log4j2 converters

See gh-49285

Signed-off-by: mvirole <virolemayank@gmail.com>

core/spring-boot/src/main/java/org/springframework/boot/ansi/AnsiStyle.java

@@ -32,7 +32,9 @@ public enum AnsiStyle implements AnsiElement {
 
 	ITALIC("3"),
 
-	UNDERLINE("4");
+	UNDERLINE("4"),
+
+	REVERSE("7");
 
 	private final String code;
 

core/spring-boot/src/main/java/org/springframework/boot/logging/log4j2/ColorConverter.java

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.logging.log4j2;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
@@ -35,6 +36,7 @@ import org.apache.logging.log4j.core.pattern.PatternFormatter;
 import org.apache.logging.log4j.core.pattern.PatternParser;
 import org.jspecify.annotations.Nullable;
 
+import org.springframework.boot.ansi.AnsiBackground;
 import org.springframework.boot.ansi.AnsiColor;
 import org.springframework.boot.ansi.AnsiElement;
 import org.springframework.boot.ansi.AnsiOutput;
@@ -42,8 +44,11 @@ import org.springframework.boot.ansi.AnsiStyle;
 
 /**
  * Log4j2 {@link LogEventPatternConverter} to color output using the {@link AnsiOutput}
- * class. A single option 'styling' can be provided to the converter, or if not specified
- * color styling will be picked based on the logging level.
+ * class. One or more styling options can be provided to the converter, or if not
+ * specified color styling will be picked based on the logging level. Supported options
+ * include foreground colors (e.g. {@code red}, {@code bright_blue}), background colors
+ * (e.g. {@code bg_red}, {@code bg_bright_green}), and text styles (e.g. {@code bold},
+ * {@code underline}, {@code reverse}).
  *
  * @author Vladimir Tsanev
  * @since 1.3.0
@@ -56,10 +61,17 @@ public final class ColorConverter extends LogEventPatternConverter {
 
 	static {
 		Map<String, AnsiElement> ansiElements = new HashMap<>();
+		// Foreground colors (e.g. "red", "bright_blue")
 		Arrays.stream(AnsiColor.values())
 			.filter((color) -> color != AnsiColor.DEFAULT)
 			.forEach((color) -> ansiElements.put(color.name().toLowerCase(Locale.ROOT), color));
-		ansiElements.put("faint", AnsiStyle.FAINT);
+		// Text styles (e.g. "bold", "italic", "underline", "reverse", "faint", "normal")
+		Arrays.stream(AnsiStyle.values())
+			.forEach((style) -> ansiElements.put(style.name().toLowerCase(Locale.ROOT), style));
+		// Background colors with "bg_" prefix (e.g. "bg_red", "bg_bright_blue")
+		Arrays.stream(AnsiBackground.values())
+			.filter((bg) -> bg != AnsiBackground.DEFAULT)
+			.forEach((bg) -> ansiElements.put("bg_" + bg.name().toLowerCase(Locale.ROOT), bg));
 		ELEMENTS = Collections.unmodifiableMap(ansiElements);
 	}
 
@@ -75,12 +87,12 @@ public final class ColorConverter extends LogEventPatternConverter {
 
 	private final List<PatternFormatter> formatters;
 
-	private final @Nullable AnsiElement styling;
+	private final List<AnsiElement> stylings;
 
-	private ColorConverter(List<PatternFormatter> formatters, @Nullable AnsiElement styling) {
+	private ColorConverter(List<PatternFormatter> formatters, List<AnsiElement> stylings) {
 		super("style", "style");
 		this.formatters = formatters;
-		this.styling = styling;
+		this.stylings = stylings;
 	}
 
 	@Override
@@ -100,13 +112,15 @@ public final class ColorConverter extends LogEventPatternConverter {
 			formatter.format(event, buf);
 		}
 		if (!buf.isEmpty()) {
-			AnsiElement element = this.styling;
-			if (element == null) {
+			if (this.stylings.isEmpty()) {
 				// Assume highlighting
-				element = LEVELS.get(event.getLevel().intLevel());
+				AnsiElement element = LEVELS.get(event.getLevel().intLevel());
 				element = (element != null) ? element : AnsiColor.GREEN;
+				appendAnsiString(toAppendTo, buf.toString(), element);
+			}
+			else {
+				appendAnsiString(toAppendTo, buf.toString(), this.stylings.toArray(new AnsiElement[0]));
 			}
-			appendAnsiString(toAppendTo, buf.toString(), element);
 		}
 	}
 
@@ -114,6 +128,13 @@ public final class ColorConverter extends LogEventPatternConverter {
 		toAppendTo.append(AnsiOutput.toString(element, in));
 	}
 
+	protected void appendAnsiString(StringBuilder toAppendTo, String in, AnsiElement... elements) {
+		Object[] ansiParams = new Object[elements.length + 1];
+		System.arraycopy(elements, 0, ansiParams, 0, elements.length);
+		ansiParams[elements.length] = in;
+		toAppendTo.append(AnsiOutput.toString(ansiParams));
+	}
+
 	/**
 	 * Creates a new instance of the class. Required by Log4J2.
 	 * @param config the configuration
@@ -131,8 +152,19 @@ public final class ColorConverter extends LogEventPatternConverter {
 		}
 		PatternParser parser = PatternLayout.createPatternParser(config);
 		List<PatternFormatter> formatters = parser.parse(options[0]);
-		AnsiElement element = (options.length != 1) ? ELEMENTS.get(options[1]) : null;
-		return new ColorConverter(formatters, element);
+		List<AnsiElement> stylings = new ArrayList<>();
+		for (int i = 1; i < options.length; i++) {
+			if (options[i] != null) {
+				String[] optionParts = options[i].split(",");
+				for (String optionPart : optionParts) {
+					AnsiElement element = ELEMENTS.get(optionPart.trim().toLowerCase(Locale.ROOT));
+					if (element != null) {
+						stylings.add(element);
+					}
+				}
+			}
+		}
+		return new ColorConverter(formatters, stylings);
 	}
 
 }

core/spring-boot/src/main/java/org/springframework/boot/logging/logback/ColorConverter.java

@@ -16,9 +16,11 @@
 
 package org.springframework.boot.logging.logback;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 
@@ -26,6 +28,7 @@ import ch.qos.logback.classic.Level;
 import ch.qos.logback.classic.spi.ILoggingEvent;
 import ch.qos.logback.core.pattern.CompositeConverter;
 
+import org.springframework.boot.ansi.AnsiBackground;
 import org.springframework.boot.ansi.AnsiColor;
 import org.springframework.boot.ansi.AnsiElement;
 import org.springframework.boot.ansi.AnsiOutput;
@@ -33,8 +36,11 @@ import org.springframework.boot.ansi.AnsiStyle;
 
 /**
  * Logback {@link CompositeConverter} to color output using the {@link AnsiOutput} class.
- * A single 'color' option can be provided to the converter, or if not specified color
- * will be picked based on the logging level.
+ * One or more styling options can be provided to the converter, or if not specified color
+ * will be picked based on the logging level. Supported options include foreground colors
+ * (e.g. {@code red}, {@code bright_blue}), background colors (e.g. {@code bg_red},
+ * {@code bg_bright_green}), and text styles (e.g. {@code bold}, {@code underline},
+ * {@code reverse}).
  *
  * @author Phillip Webb
  * @since 1.0.0
@@ -45,10 +51,17 @@ public class ColorConverter extends CompositeConverter<ILoggingEvent> {
 
 	static {
 		Map<String, AnsiElement> ansiElements = new HashMap<>();
+		// Foreground colors (e.g. "red", "bright_blue")
 		Arrays.stream(AnsiColor.values())
 			.filter((color) -> color != AnsiColor.DEFAULT)
 			.forEach((color) -> ansiElements.put(color.name().toLowerCase(Locale.ROOT), color));
-		ansiElements.put("faint", AnsiStyle.FAINT);
+		// Text styles (e.g. "bold", "italic", "underline", "reverse", "faint", "normal")
+		Arrays.stream(AnsiStyle.values())
+			.forEach((style) -> ansiElements.put(style.name().toLowerCase(Locale.ROOT), style));
+		// Background colors with "bg_" prefix (e.g. "bg_red", "bg_bright_blue")
+		Arrays.stream(AnsiBackground.values())
+			.filter((bg) -> bg != AnsiBackground.DEFAULT)
+			.forEach((bg) -> ansiElements.put("bg_" + bg.name().toLowerCase(Locale.ROOT), bg));
 		ELEMENTS = Collections.unmodifiableMap(ansiElements);
 	}
 
@@ -63,19 +76,38 @@ public class ColorConverter extends CompositeConverter<ILoggingEvent> {
 
 	@Override
 	protected String transform(ILoggingEvent event, String in) {
-		AnsiElement color = ELEMENTS.get(getFirstOption());
-		if (color == null) {
-			// Assume highlighting
-			color = LEVELS.get(event.getLevel().toInteger());
-			color = (color != null) ? color : AnsiColor.GREEN;
+		List<String> options = getOptionList();
+		List<AnsiElement> elements = new ArrayList<>();
+		if (options != null) {
+			for (String option : options) {
+				String[] optionParts = option.split(",");
+				for (String optionPart : optionParts) {
+					AnsiElement element = ELEMENTS.get(optionPart.trim().toLowerCase(Locale.ROOT));
+					if (element != null) {
+						elements.add(element);
+					}
+				}
+			}
 		}
-		return toAnsiString(in, color);
+		if (elements.isEmpty()) {
+			// Assume highlighting
+			AnsiElement element = LEVELS.get(event.getLevel().toInteger());
+			elements.add((element != null) ? element : AnsiColor.GREEN);
+		}
+		return toAnsiString(in, elements.toArray(new AnsiElement[0]));
 	}
 
 	protected String toAnsiString(String in, AnsiElement element) {
 		return AnsiOutput.toString(element, in);
 	}
 
+	protected String toAnsiString(String in, AnsiElement... elements) {
+		Object[] ansiParams = new Object[elements.length + 1];
+		System.arraycopy(elements, 0, ansiParams, 0, elements.length);
+		ansiParams[elements.length] = in;
+		return AnsiOutput.toString(ansiParams);
+	}
+
 	static String getName(AnsiElement element) {
 		return ELEMENTS.entrySet()
 			.stream()

core/spring-boot/src/test/java/org/springframework/boot/logging/log4j2/ColorConverterTests.java

@@ -173,11 +173,88 @@ class ColorConverterTests {
 		assertThat(output).hasToString("\033[96min\033[0;39m");
 	}
 
+	@Test
+	void bold() {
+		StringBuilder output = new StringBuilder();
+		newConverter("bold").format(this.event, output);
+		assertThat(output).hasToString("\033[1min\033[0;39m");
+	}
+
+	@Test
+	void italic() {
+		StringBuilder output = new StringBuilder();
+		newConverter("italic").format(this.event, output);
+		assertThat(output).hasToString("\033[3min\033[0;39m");
+	}
+
+	@Test
+	void underline() {
+		StringBuilder output = new StringBuilder();
+		newConverter("underline").format(this.event, output);
+		assertThat(output).hasToString("\033[4min\033[0;39m");
+	}
+
+	@Test
+	void reverse() {
+		StringBuilder output = new StringBuilder();
+		newConverter("reverse").format(this.event, output);
+		assertThat(output).hasToString("\033[7min\033[0;39m");
+	}
+
+	@Test
+	void bgRed() {
+		StringBuilder output = new StringBuilder();
+		newConverter("bg_red").format(this.event, output);
+		assertThat(output).hasToString("\033[41min\033[0;39m");
+	}
+
+	@Test
+	void bgGreen() {
+		StringBuilder output = new StringBuilder();
+		newConverter("bg_green").format(this.event, output);
+		assertThat(output).hasToString("\033[42min\033[0;39m");
+	}
+
+	@Test
+	void bgYellow() {
+		StringBuilder output = new StringBuilder();
+		newConverter("bg_yellow").format(this.event, output);
+		assertThat(output).hasToString("\033[43min\033[0;39m");
+	}
+
+	@Test
+	void bgBlue() {
+		StringBuilder output = new StringBuilder();
+		newConverter("bg_blue").format(this.event, output);
+		assertThat(output).hasToString("\033[44min\033[0;39m");
+	}
+
+	@Test
+	void bgBrightRed() {
+		StringBuilder output = new StringBuilder();
+		newConverter("bg_bright_red").format(this.event, output);
+		assertThat(output).hasToString("\033[101min\033[0;39m");
+	}
+
+	@Test
+	void multipleStylesCommaSeparated() {
+		StringBuilder output = new StringBuilder();
+		newConverter("bold, red").format(this.event, output);
+		assertThat(output).hasToString("\033[1;31min\033[0;39m");
+	}
+
+	@Test
+	void multipleStylesMultipleOptions() {
+		StringBuilder output = new StringBuilder();
+		newConverter("bold", "red").format(this.event, output);
+		assertThat(output).hasToString("\033[1;31min\033[0;39m");
+	}
+
 	@Test
 	void highlightFatal() {
 		this.event.setLevel(Level.FATAL);
 		StringBuilder output = new StringBuilder();
-		newConverter(null).format(this.event, output);
+		newConverter((String) null).format(this.event, output);
 		assertThat(output).hasToString("\033[31min\033[0;39m");
 	}
 
@@ -185,7 +262,7 @@ class ColorConverterTests {
 	void highlightError() {
 		this.event.setLevel(Level.ERROR);
 		StringBuilder output = new StringBuilder();
-		newConverter(null).format(this.event, output);
+		newConverter((String) null).format(this.event, output);
 		assertThat(output).hasToString("\033[31min\033[0;39m");
 	}
 
@@ -193,7 +270,7 @@ class ColorConverterTests {
 	void highlightWarn() {
 		this.event.setLevel(Level.WARN);
 		StringBuilder output = new StringBuilder();
-		newConverter(null).format(this.event, output);
+		newConverter((String) null).format(this.event, output);
 		assertThat(output).hasToString("\033[33min\033[0;39m");
 	}
 
@@ -201,7 +278,7 @@ class ColorConverterTests {
 	void highlightDebug() {
 		this.event.setLevel(Level.DEBUG);
 		StringBuilder output = new StringBuilder();
-		newConverter(null).format(this.event, output);
+		newConverter((String) null).format(this.event, output);
 		assertThat(output).hasToString("\033[32min\033[0;39m");
 	}
 
@@ -209,12 +286,18 @@ class ColorConverterTests {
 	void highlightTrace() {
 		this.event.setLevel(Level.TRACE);
 		StringBuilder output = new StringBuilder();
-		newConverter(null).format(this.event, output);
+		newConverter((String) null).format(this.event, output);
 		assertThat(output).hasToString("\033[32min\033[0;39m");
 	}
 
-	private ColorConverter newConverter(@Nullable String styling) {
-		ColorConverter converter = ColorConverter.newInstance(null, new String[] { this.in, styling });
+	private ColorConverter newConverter(@Nullable String... stylings) {
+		if (stylings == null) {
+			stylings = new String[] { null };
+		}
+		String[] options = new String[1 + stylings.length];
+		options[0] = this.in;
+		System.arraycopy(stylings, 0, options, 1, stylings.length);
+		ColorConverter converter = ColorConverter.newInstance(null, options);
 		assertThat(converter).isNotNull();
 		return converter;
 	}

core/spring-boot/src/test/java/org/springframework/boot/logging/logback/ColorConverterTests.java

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.logging.logback;
 
+import java.util.Arrays;
 import java.util.Collections;
 
 import ch.qos.logback.classic.Level;
@@ -170,6 +171,83 @@ class ColorConverterTests {
 		assertThat(out).isEqualTo("\033[96min\033[0;39m");
 	}
 
+	@Test
+	void bold() {
+		this.converter.setOptionList(Collections.singletonList("bold"));
+		String out = this.converter.transform(this.event, this.in);
+		assertThat(out).isEqualTo("\033[1min\033[0;39m");
+	}
+
+	@Test
+	void italic() {
+		this.converter.setOptionList(Collections.singletonList("italic"));
+		String out = this.converter.transform(this.event, this.in);
+		assertThat(out).isEqualTo("\033[3min\033[0;39m");
+	}
+
+	@Test
+	void underline() {
+		this.converter.setOptionList(Collections.singletonList("underline"));
+		String out = this.converter.transform(this.event, this.in);
+		assertThat(out).isEqualTo("\033[4min\033[0;39m");
+	}
+
+	@Test
+	void reverse() {
+		this.converter.setOptionList(Collections.singletonList("reverse"));
+		String out = this.converter.transform(this.event, this.in);
+		assertThat(out).isEqualTo("\033[7min\033[0;39m");
+	}
+
+	@Test
+	void bgRed() {
+		this.converter.setOptionList(Collections.singletonList("bg_red"));
+		String out = this.converter.transform(this.event, this.in);
+		assertThat(out).isEqualTo("\033[41min\033[0;39m");
+	}
+
+	@Test
+	void bgGreen() {
+		this.converter.setOptionList(Collections.singletonList("bg_green"));
+		String out = this.converter.transform(this.event, this.in);
+		assertThat(out).isEqualTo("\033[42min\033[0;39m");
+	}
+
+	@Test
+	void bgYellow() {
+		this.converter.setOptionList(Collections.singletonList("bg_yellow"));
+		String out = this.converter.transform(this.event, this.in);
+		assertThat(out).isEqualTo("\033[43min\033[0;39m");
+	}
+
+	@Test
+	void bgBlue() {
+		this.converter.setOptionList(Collections.singletonList("bg_blue"));
+		String out = this.converter.transform(this.event, this.in);
+		assertThat(out).isEqualTo("\033[44min\033[0;39m");
+	}
+
+	@Test
+	void bgBrightRed() {
+		this.converter.setOptionList(Collections.singletonList("bg_bright_red"));
+		String out = this.converter.transform(this.event, this.in);
+		assertThat(out).isEqualTo("\033[101min\033[0;39m");
+	}
+
+	@Test
+	void multipleStylesCommaSeparated() {
+		this.converter.setOptionList(Collections.singletonList("bold, red"));
+		String out = this.converter.transform(this.event, this.in);
+		assertThat(out).isEqualTo("\033[1;31min\033[0;39m");
+	}
+
+	@Test
+	void multipleStyles() {
+		this.converter.setOptionList(Arrays.asList("bold", "red"));
+		String out = this.converter.transform(this.event, this.in);
+		assertThat(out).isEqualTo("\033[1;31min\033[0;39m");
+	}
+
 	@Test
 	void highlightError() {
 		this.event.setLevel(Level.ERROR);