Add ANSI 8-bit color support

Update ANSI property support to include an 8-bit (256 color) option.

See gh-18264

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

@@ -28,6 +28,7 @@ import java.util.Map;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
+import org.springframework.boot.ansi.Ansi256PropertySource;
 import org.springframework.boot.ansi.AnsiPropertySource;
 import org.springframework.core.env.Environment;
 import org.springframework.core.env.MapPropertySource;
@@ -43,6 +44,7 @@ import org.springframework.util.StreamUtils;
  *
  * @author Phillip Webb
  * @author Vedran Pavic
+ * @author Toshiaki Maki
  * @since 1.2.0
  */
 public class ResourceBanner implements Banner {
@@ -80,6 +82,7 @@ public class ResourceBanner implements Banner {
 		resolvers.add(environment);
 		resolvers.add(getVersionResolver(sourceClass));
 		resolvers.add(getAnsiResolver());
+		resolvers.add(getAnsi256Resolver());
 		resolvers.add(getTitleResolver(sourceClass));
 		return resolvers;
 	}
@@ -123,6 +126,12 @@ public class ResourceBanner implements Banner {
 		return new PropertySourcesPropertyResolver(sources);
 	}
 
+	private PropertyResolver getAnsi256Resolver() {
+		MutablePropertySources sources = new MutablePropertySources();
+		sources.addFirst(new Ansi256PropertySource("ansi256"));
+		return new PropertySourcesPropertyResolver(sources);
+	}
+
 	private PropertyResolver getTitleResolver(Class<?> sourceClass) {
 		MutablePropertySources sources = new MutablePropertySources();
 		String applicationTitle = getApplicationTitle(sourceClass);

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/ansi/Ansi256Color.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2012-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.ansi;
+
+/**
+ * {@link AnsiElement} implementation for Ansi 256 colors.
+ * <p>
+ * use {@link Ansi256Color.Foreground} or {@link Ansi256Color.Background} as a concrete
+ * class.
+ *
+ * @author Toshiaki Maki
+ * @since 2.2.0
+ */
+public abstract class Ansi256Color implements AnsiElement {
+
+	/**
+	 * color code
+	 */
+	final int colorCode;
+
+	/**
+	 * @param colorCode color code (must be 0-255)
+	 * @throws IllegalArgumentException if color code is not between 0 and 255.
+	 */
+	Ansi256Color(int colorCode) {
+		if (colorCode < 0 || colorCode > 255) {
+			throw new IllegalArgumentException("'colorCode' must be between 0 and 255.");
+		}
+		this.colorCode = colorCode;
+	}
+
+	/**
+	 * {@link Ansi256Color} foreground colors.
+	 *
+	 * @author Toshiaki Maki
+	 * @since 2.2.0
+	 */
+	public static class Foreground extends Ansi256Color {
+
+		public Foreground(int colorCode) {
+			super(colorCode);
+		}
+
+		@Override
+		public String toString() {
+			return "38;5;" + super.colorCode;
+		}
+
+	}
+
+	/**
+	 * {@link Ansi256Color} background colors.
+	 *
+	 * @author Toshiaki Maki
+	 * @since 2.2.0
+	 */
+	public static class Background extends Ansi256Color {
+
+		public Background(int colorCode) {
+			super(colorCode);
+		}
+
+		@Override
+		public String toString() {
+			return "48;5;" + super.colorCode;
+		}
+
+	}
+
+}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/ansi/Ansi256PropertySource.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2012-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.ansi;
+
+import org.springframework.core.env.PropertyResolver;
+import org.springframework.core.env.PropertySource;
+import org.springframework.util.StringUtils;
+
+/**
+ * {@link PropertyResolver} for {@link Ansi256Color.Background} and
+ * {@link Ansi256Color.Foreground} elements. Supports properties of the form
+ * {@code Ansi256Color.Foreground_N} and {@code Ansi256Color.Background_N} ({@code N} must
+ * be between 0 and 255).
+ *
+ * @author Toshiaki Maki
+ * @since 2.2.0
+ */
+public class Ansi256PropertySource extends PropertySource<AnsiElement> {
+
+	private static final String PREFIX = "Ansi256Color.";
+
+	private static final String FOREGROUND_PREFIX = PREFIX + "Foreground_";
+
+	private static final String BACKGROUND_PREFIX = PREFIX + "Background_";
+
+	/**
+	 * Create a new {@link Ansi256PropertySource} instance.
+	 * @param name the name of the property source
+	 */
+	public Ansi256PropertySource(String name) {
+		super(name);
+	}
+
+	@Override
+	public Object getProperty(String name) {
+		if (StringUtils.hasLength(name)) {
+			if (name.startsWith(FOREGROUND_PREFIX)) {
+				final int colorCode = Integer.parseInt(name.substring(FOREGROUND_PREFIX.length()));
+				return AnsiOutput.encode(new Ansi256Color.Foreground(colorCode));
+			}
+			else if (name.startsWith(BACKGROUND_PREFIX)) {
+				final int colorCode = Integer.parseInt(name.substring(BACKGROUND_PREFIX.length()));
+				return AnsiOutput.encode(new Ansi256Color.Background(colorCode));
+			}
+		}
+		return null;
+	}
+
+}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/ResourceBannerTests.java

@@ -39,6 +39,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  *
  * @author Phillip Webb
  * @author Vedran Pavic
+ * @author Toshiaki Maki
  */
 class ResourceBannerTests {
 
@@ -95,6 +96,24 @@ class ResourceBannerTests {
 		assertThat(banner).startsWith("This is red.");
 	}
 
+	@Test
+	void renderWith256Colors() {
+		Resource resource = new ByteArrayResource(
+				"${Ansi256Color.Foreground_208}This is orange.${Ansi.NORMAL}".getBytes());
+		AnsiOutput.setEnabled(AnsiOutput.Enabled.ALWAYS);
+		String banner = printBanner(resource, null, null, null);
+		assertThat(banner).startsWith("\033[38;5;208mThis is orange.\u001B[0m");
+	}
+
+	@Test
+	void renderWith256ColorsButDisabled() {
+		Resource resource = new ByteArrayResource(
+				"${Ansi256Color.Foreground_208}This is orange.${Ansi.NORMAL}".getBytes());
+		AnsiOutput.setEnabled(AnsiOutput.Enabled.NEVER);
+		String banner = printBanner(resource, null, null, null);
+		assertThat(banner).startsWith("This is orange.");
+	}
+
 	@Test
 	void renderWithTitle() {
 		Resource resource = new ByteArrayResource("banner ${application.title} ${a}".getBytes());

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/ansi/Ansi256ColorTest.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2012-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.ansi;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.failBecauseExceptionWasNotThrown;
+
+/**
+ * Tests for {@link Ansi256Color}.
+ *
+ * @author Toshiaki Maki
+ */
+class Ansi256ColorTest {
+
+	@Test
+	void testForeground() {
+		final Ansi256Color ansi256Color = new Ansi256Color.Foreground(208);
+		assertThat(ansi256Color.toString()).isEqualTo("38;5;208");
+	}
+
+	@Test
+	void testBackground() {
+		final Ansi256Color ansi256Color = new Ansi256Color.Background(208);
+		assertThat(ansi256Color.toString()).isEqualTo("48;5;208");
+	}
+
+	@Test
+	void testIllegalColorCode() {
+		try {
+			new Ansi256Color.Foreground(256);
+			failBecauseExceptionWasNotThrown(IllegalArgumentException.class);
+		}
+		catch (IllegalArgumentException ex) {
+			assertThat(ex.getMessage()).isEqualTo("'colorCode' must be between 0 and 255.");
+		}
+	}
+
+}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/ansi/Ansi256PropertySourceTest.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2012-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.ansi;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link Ansi256PropertySource}.
+ *
+ * @author Toshiaki Maki
+ */
+class Ansi256PropertySourceTest {
+
+	private Ansi256PropertySource source = new Ansi256PropertySource("ansi256");
+
+	@AfterEach
+	void reset() {
+		AnsiOutput.setEnabled(AnsiOutput.Enabled.DETECT);
+	}
+
+	@Test
+	void getPropertyShouldConvertAnsi256ColorForeground() {
+		AnsiOutput.setEnabled(AnsiOutput.Enabled.ALWAYS);
+		final Object property = this.source.getProperty("Ansi256Color.Foreground_100");
+		assertThat(property).isEqualTo("\033[38;5;100m");
+	}
+
+	@Test
+	void getPropertyShouldConvertAnsi256ColorBackground() {
+		AnsiOutput.setEnabled(AnsiOutput.Enabled.ALWAYS);
+		final Object property = this.source.getProperty("Ansi256Color.Background_100");
+		assertThat(property).isEqualTo("\033[48;5;100m");
+	}
+
+	@Test
+	void getMissingPropertyShouldReturnNull() {
+		AnsiOutput.setEnabled(AnsiOutput.Enabled.ALWAYS);
+		final Object property = this.source.getProperty("Ansi256Color.ForeGround_100");
+		assertThat(property).isNull();
+	}
+
+}