Merge pull request #4647 from craigburke/image-banner

* image-banner:
  Add image banner documentation
  Rework ImageBanner Support
  Add ImageBanner color distance calculation
  Support image based banners

spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -31,6 +31,11 @@ content into your application; rather pick only the properties that you need.
 	# BANNER
 	banner.charset=UTF-8 # Banner file encoding.
 	banner.location=classpath:banner.txt # Banner file location.
+	banner.image.location=classpath:banner.gif # (Banner image file location, jpg/png can also be used).
+	banner.image.width= # Width of the banner image in chars (default 76)
+	banner.image.hight= # Height of the banner image in chars (default based on image height)
+	banner.image.margin= # Left hand image margin in chars (default 2)
+	banner.image.invert= # If images should be inverted for dark terminal themes (default false)
 
 	# LOGGING
 	logging.config= # Location of the logging configuration file. For instance `classpath:logback.xml` for Logback

spring-boot-docs/src/main/asciidoc/howto.adoc

@@ -212,8 +212,8 @@ might have.
 
 [source,properties,indent=0,subs="verbatim,quotes,attributes"]
 ----
-	spring.main.web_environment=false
-	spring.main.banner_mode=off
+	spring.main.web-environment=false
+	spring.main.banner-mode=off
 ----
 
 and then the Spring Boot banner will not be printed on startup, and the application will
@@ -239,7 +239,7 @@ used with the following configuration:
 [source,properties,indent=0,subs="verbatim,quotes,attributes"]
 ----
 	spring.main.sources=com.acme.Config,com.acme.ExtraConfig
-	spring.main.banner_mode=console
+	spring.main.banner-mode=console
 ----
 
 The actual application will _now_ show the banner (as overridden by configuration) and use

spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -52,8 +52,11 @@ such as the user that launched the application.
 The banner that is printed on start up can be changed by adding a `banner.txt` file
 to your classpath, or by setting `banner.location` to the location of such a file.
 If the file has an unusual encoding you can set `banner.charset` (default is `UTF-8`).
+In addition a text file, you can also add a `banner.gif`, `banner.jpg` or `banner.png`
+image file to your classpath, or set a `banner.image.location` property. Images will be
+converted into an ASCII art representation and printed above any text banner.
 
-You can use the following variables inside your `banner.txt` file:
+Inside your `banner.txt` file you can use any of the following placeholders:
 
 .Banner variables
 |===

spring-boot-samples/spring-boot-sample-simple/src/main/resources/banner.txt

@@ -0,0 +1 @@
+${Ansi.GREEN} :: Sample application build with Spring Boot${spring-boot.formatted-version} ::${Ansi.DEFAULT}

spring-boot/src/main/java/org/springframework/boot/ImageBanner.java

@@ -0,0 +1,180 @@
+/*
+ * Copyright 2012-2015 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
+ *
+ *      http://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;
+
+import java.awt.Color;
+import java.awt.Image;
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.PrintStream;
+
+import javax.imageio.ImageIO;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import org.springframework.boot.ansi.AnsiBackground;
+import org.springframework.boot.ansi.AnsiColor;
+import org.springframework.boot.ansi.AnsiColors;
+import org.springframework.boot.ansi.AnsiElement;
+import org.springframework.boot.ansi.AnsiOutput;
+import org.springframework.boot.bind.RelaxedPropertyResolver;
+import org.springframework.core.env.Environment;
+import org.springframework.core.env.PropertyResolver;
+import org.springframework.core.io.Resource;
+import org.springframework.util.Assert;
+
+/**
+ * Banner implementation that prints ASCII art generated from an image resource
+ * {@link Resource}.
+ *
+ * @author Craig Burke
+ * @author Phillip Webb
+ * @since 1.4.0
+ */
+public class ImageBanner implements Banner {
+
+	private static final Log log = LogFactory.getLog(ImageBanner.class);
+
+	private static final double[] RGB_WEIGHT = { 0.2126d, 0.7152d, 0.0722d };
+
+	private static final char[] PIXEL = { ' ', '.', '*', ':', 'o', '&', '8', '#', '@' };
+
+	private static final int LUMINANCE_INCREMENT = 10;
+
+	private static final int LUMINANCE_START = LUMINANCE_INCREMENT * PIXEL.length;
+
+	private final Resource image;
+
+	public ImageBanner(Resource image) {
+		Assert.notNull(image, "Image must not be null");
+		Assert.isTrue(image.exists(), "Image must exist");
+		this.image = image;
+	}
+
+	@Override
+	public void printBanner(Environment environment, Class<?> sourceClass,
+			PrintStream out) {
+		String headless = System.getProperty("java.awt.headless");
+		try {
+			System.setProperty("java.awt.headless", "true");
+			printBanner(environment, out);
+		}
+		catch (Exception ex) {
+			log.warn("Image banner not printable: " + this.image + " (" + ex.getClass()
+					+ ": '" + ex.getMessage() + "')", ex);
+		}
+		finally {
+			if (headless == null) {
+				System.clearProperty("java.awt.headless");
+			}
+			else {
+				System.setProperty("java.awt.headless", headless);
+			}
+		}
+	}
+
+	private void printBanner(Environment environment, PrintStream out)
+			throws IOException {
+		PropertyResolver properties = new RelaxedPropertyResolver(environment,
+				"banner.image.");
+		int width = properties.getProperty("width", Integer.class, 76);
+		int heigth = properties.getProperty("height", Integer.class, 0);
+		int margin = properties.getProperty("margin", Integer.class, 2);
+		boolean invert = properties.getProperty("invert", Boolean.class, false);
+		BufferedImage image = readImage(width, heigth);
+		printBanner(image, margin, invert, out);
+	}
+
+	private BufferedImage readImage(int width, int heigth) throws IOException {
+		InputStream inputStream = this.image.getInputStream();
+		try {
+			BufferedImage image = ImageIO.read(inputStream);
+			return resizeImage(image, width, heigth);
+		}
+		finally {
+			inputStream.close();
+		}
+	}
+
+	private BufferedImage resizeImage(BufferedImage image, int width, int height) {
+		if (width < 1) {
+			width = 1;
+		}
+		if (height <= 0) {
+			double aspectRatio = (double) width / image.getWidth() * 0.5;
+			height = (int) Math.ceil(image.getHeight() * aspectRatio);
+		}
+		BufferedImage resized = new BufferedImage(width, height,
+				BufferedImage.TYPE_INT_RGB);
+		Image scaled = image.getScaledInstance(width, height, Image.SCALE_DEFAULT);
+		resized.getGraphics().drawImage(scaled, 0, 0, null);
+		return resized;
+	}
+
+	private void printBanner(BufferedImage image, int margin, boolean invert,
+			PrintStream out) {
+		AnsiElement background = (invert ? AnsiBackground.BLACK : AnsiBackground.DEFAULT);
+		out.print(AnsiOutput.encode(AnsiColor.DEFAULT));
+		out.print(AnsiOutput.encode(background));
+		out.println();
+		out.println();
+		AnsiColor lastColor = AnsiColor.DEFAULT;
+		for (int y = 0; y < image.getHeight(); y++) {
+			for (int i = 0; i < margin; i++) {
+				out.print(" ");
+			}
+			for (int x = 0; x < image.getWidth(); x++) {
+				Color color = new Color(image.getRGB(x, y), false);
+				AnsiColor ansiColor = AnsiColors.getClosest(color);
+				if (ansiColor != lastColor) {
+					out.print(AnsiOutput.encode(ansiColor));
+					lastColor = ansiColor;
+				}
+				out.print(getAsciiPixel(color, invert));
+			}
+			out.println();
+		}
+		out.print(AnsiOutput.encode(AnsiColor.DEFAULT));
+		out.print(AnsiOutput.encode(AnsiBackground.DEFAULT));
+		out.println();
+	}
+
+	private char getAsciiPixel(Color color, boolean dark) {
+		double luminance = getLuminance(color, dark);
+		for (int i = 0; i < PIXEL.length; i++) {
+			if (luminance >= (LUMINANCE_START - (i * LUMINANCE_INCREMENT))) {
+				return PIXEL[i];
+			}
+		}
+		return PIXEL[PIXEL.length - 1];
+	}
+
+	private int getLuminance(Color color, boolean inverse) {
+		double luminance = 0.0;
+		luminance += getLuminance(color.getRed(), inverse, RGB_WEIGHT[0]);
+		luminance += getLuminance(color.getGreen(), inverse, RGB_WEIGHT[1]);
+		luminance += getLuminance(color.getBlue(), inverse, RGB_WEIGHT[2]);
+		return (int) Math.ceil((luminance / 0xFF) * 100);
+	}
+
+	private double getLuminance(int component, boolean inverse, double weight) {
+		return (inverse ? 0xFF - component : component) * weight;
+	}
+
+}

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

@@ -38,7 +38,7 @@ import org.springframework.util.Assert;
 import org.springframework.util.StreamUtils;
 
 /**
- * Banner implementation that prints from a source {@link Resource}.
+ * Banner implementation that prints from a source text {@link Resource}.
  *
  * @author Phillip Webb
  * @author Vedran Pavic

spring-boot/src/main/java/org/springframework/boot/SpringApplication.java

@@ -16,9 +16,6 @@
 
 package org.springframework.boot;
 
-import java.io.ByteArrayOutputStream;
-import java.io.PrintStream;
-import java.io.UnsupportedEncodingException;
 import java.lang.reflect.Constructor;
 import java.security.AccessControlException;
 import java.util.ArrayList;
@@ -41,6 +38,7 @@ import org.springframework.beans.factory.groovy.GroovyBeanDefinitionReader;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.BeanNameGenerator;
 import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
+import org.springframework.boot.Banner.Mode;
 import org.springframework.boot.diagnostics.FailureAnalyzers;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextInitializer;
@@ -140,6 +138,7 @@ import org.springframework.web.context.support.StandardServletEnvironment;
  * @author Christian Dupuis
  * @author Stephane Nicoll
  * @author Jeremy Rickard
+ * @author Craig Burke
  * @see #run(Object, String[])
  * @see #run(Object[], String[])
  * @see #SpringApplication(Object...)
@@ -166,19 +165,17 @@ public class SpringApplication {
 	/**
 	 * Default banner location.
 	 */
-	public static final String BANNER_LOCATION_PROPERTY_VALUE = "banner.txt";
+	public static final String BANNER_LOCATION_PROPERTY_VALUE = SpringApplicationBannerPrinter.DEFAULT_BANNER_LOCATION;
 
 	/**
 	 * Banner location property key.
 	 */
-	public static final String BANNER_LOCATION_PROPERTY = "banner.location";
+	public static final String BANNER_LOCATION_PROPERTY = SpringApplicationBannerPrinter.BANNER_LOCATION_PROPERTY;
 
 	private static final String CONFIGURABLE_WEB_ENVIRONMENT_CLASS = "org.springframework.web.context.ConfigurableWebEnvironment";
 
 	private static final String SYSTEM_PROPERTY_JAVA_AWT_HEADLESS = "java.awt.headless";
 
-	private static final Banner DEFAULT_BANNER = new SpringBootBanner();
-
 	private static final Set<String> SERVLET_ENVIRONMENT_SOURCE_NAMES;
 
 	static {
@@ -542,42 +539,16 @@ public class SpringApplication {
 	 * @see #setBannerMode
 	 */
 	protected void printBanner(Environment environment) {
-		Banner selectedBanner = selectBanner(environment);
-		if (this.bannerMode == Banner.Mode.LOG) {
-			try {
-				logger.info(createStringFromBanner(selectedBanner, environment));
-			}
-			catch (UnsupportedEncodingException ex) {
-				logger.warn("Failed to create String for banner", ex);
-			}
-		}
-		else {
-			selectedBanner.printBanner(environment, this.mainApplicationClass,
-					System.out);
-		}
-	}
-
-	private Banner selectBanner(Environment environment) {
-		String location = environment.getProperty(BANNER_LOCATION_PROPERTY,
-				BANNER_LOCATION_PROPERTY_VALUE);
 		ResourceLoader resourceLoader = this.resourceLoader != null ? this.resourceLoader
 				: new DefaultResourceLoader(getClassLoader());
-		Resource resource = resourceLoader.getResource(location);
-		if (resource.exists()) {
-			return new ResourceBanner(resource);
+		SpringApplicationBannerPrinter banner = new SpringApplicationBannerPrinter(resourceLoader,
+				this.banner);
+		if (this.bannerMode == Mode.LOG) {
+			banner.print(environment, this.mainApplicationClass, logger);
 		}
-		if (this.banner != null) {
-			return this.banner;
+		else {
+			banner.print(environment, this.mainApplicationClass, System.out);
 		}
-		return DEFAULT_BANNER;
-	}
-
-	private String createStringFromBanner(Banner banner, Environment environment)
-			throws UnsupportedEncodingException {
-		ByteArrayOutputStream baos = new ByteArrayOutputStream();
-		banner.printBanner(environment, this.mainApplicationClass, new PrintStream(baos));
-		String charset = environment.getProperty("banner.charset", "UTF-8");
-		return baos.toString(charset);
 	}
 
 	/**

spring-boot/src/main/java/org/springframework/boot/SpringApplicationBannerPrinter.java

@@ -0,0 +1,146 @@
+/*
+ * Copyright 2012-2016 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
+ *
+ *      http://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;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+import java.io.UnsupportedEncodingException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.logging.Log;
+
+import org.springframework.core.env.Environment;
+import org.springframework.core.io.Resource;
+import org.springframework.core.io.ResourceLoader;
+import org.springframework.util.StringUtils;
+
+/**
+ * Class used by {@link SpringApplication} to print the application banner.
+ *
+ * @author Phillip Webb
+ */
+class SpringApplicationBannerPrinter {
+
+	static final String BANNER_LOCATION_PROPERTY = "banner.location";
+
+	static final String BANNER_IMAGE_LOCATION_PROPERTY = "banner.image.location";
+
+	static final String DEFAULT_BANNER_LOCATION = "banner.txt";
+
+	static final String[] IMAGE_EXTENSION = { "gif", "jpg", "png" };
+
+	private static final Banner DEFAULT_BANNER = new SpringBootBanner();
+
+	private final ResourceLoader resourceLoader;
+
+	private final Banner fallbackBanner;
+
+	SpringApplicationBannerPrinter(ResourceLoader resourceLoader, Banner fallbackBanner) {
+		this.resourceLoader = resourceLoader;
+		this.fallbackBanner = fallbackBanner;
+	}
+
+	public void print(Environment environment, Class<?> sourceClass, Log logger) {
+		Banner banner = getBanner(environment, this.fallbackBanner);
+		try {
+			logger.info(createStringFromBanner(banner, environment, sourceClass));
+		}
+		catch (UnsupportedEncodingException ex) {
+			logger.warn("Failed to create String for banner", ex);
+		}
+	}
+
+	public void print(Environment environment, Class<?> sourceClass, PrintStream out) {
+		Banner banner = getBanner(environment, this.fallbackBanner);
+		banner.printBanner(environment, sourceClass, out);
+	}
+
+	private Banner getBanner(Environment environment, Banner definedBanner) {
+		Banners banners = new Banners();
+		banners.addIfNotNull(getImageBanner(environment));
+		banners.addIfNotNull(getTextBanner(environment));
+		if (banners.hasAtLeastOneBanner()) {
+			return banners;
+		}
+		if (this.fallbackBanner != null) {
+			return this.fallbackBanner;
+		}
+		return DEFAULT_BANNER;
+	}
+
+	private Banner getTextBanner(Environment environment) {
+		String location = environment.getProperty(BANNER_LOCATION_PROPERTY,
+				DEFAULT_BANNER_LOCATION);
+		Resource resource = this.resourceLoader.getResource(location);
+		if (resource.exists()) {
+			return new ResourceBanner(resource);
+		}
+		return null;
+	}
+
+	private Banner getImageBanner(Environment environment) {
+		String location = environment.getProperty(BANNER_IMAGE_LOCATION_PROPERTY);
+		if (StringUtils.hasLength(location)) {
+			Resource resource = this.resourceLoader.getResource(location);
+			return (resource.exists() ? new ImageBanner(resource) : null);
+		}
+		for (String ext : IMAGE_EXTENSION) {
+			Resource resource = this.resourceLoader.getResource("banner." + ext);
+			if (resource.exists()) {
+				return new ImageBanner(resource);
+			}
+		}
+		return null;
+	}
+
+	private String createStringFromBanner(Banner banner, Environment environment,
+			Class<?> mainApplicationClass) throws UnsupportedEncodingException {
+		ByteArrayOutputStream baos = new ByteArrayOutputStream();
+		banner.printBanner(environment, mainApplicationClass, new PrintStream(baos));
+		String charset = environment.getProperty("banner.charset", "UTF-8");
+		return baos.toString(charset);
+	}
+
+	/**
+	 * {@link Banner} comprised of other {@link Banner Banners}.
+	 */
+	private static class Banners implements Banner {
+
+		private final List<Banner> banners = new ArrayList<Banner>();
+
+		public void addIfNotNull(Banner banner) {
+			if (banner != null) {
+				this.banners.add(banner);
+			}
+		}
+
+		public boolean hasAtLeastOneBanner() {
+			return !this.banners.isEmpty();
+		}
+
+		@Override
+		public void printBanner(Environment environment, Class<?> sourceClass,
+				PrintStream out) {
+			for (Banner banner : this.banners) {
+				banner.printBanner(environment, sourceClass, out);
+			}
+		}
+
+	}
+
+}

spring-boot/src/main/java/org/springframework/boot/ansi/AnsiColors.java

@@ -0,0 +1,140 @@
+/*
+ * Copyright 2012-2016 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
+ *
+ *      http://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 java.awt.Color;
+import java.awt.color.ColorSpace;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import org.springframework.util.Assert;
+
+/**
+ * Utility for working with {@link AnsiColor} in the context of {@link Color AWT Colors}.
+ *
+ * @author Craig Burke
+ * @author Ruben Dijkstra
+ * @author Phillip Webb
+ * @author Michael Simons
+ * @since 1.4.0
+ */
+public final class AnsiColors {
+
+	private static final Map<AnsiColor, LabColor> ANSI_COLOR_MAP;
+
+	static {
+		Map<AnsiColor, LabColor> colorMap = new LinkedHashMap<AnsiColor, LabColor>();
+		colorMap.put(AnsiColor.BLACK, new LabColor(0x000000));
+		colorMap.put(AnsiColor.RED, new LabColor(0xAA0000));
+		colorMap.put(AnsiColor.GREEN, new LabColor(0x00AA00));
+		colorMap.put(AnsiColor.YELLOW, new LabColor(0xAA5500));
+		colorMap.put(AnsiColor.BLUE, new LabColor(0x0000AA));
+		colorMap.put(AnsiColor.MAGENTA, new LabColor(0xAA00AA));
+		colorMap.put(AnsiColor.CYAN, new LabColor(0x00AAAA));
+		colorMap.put(AnsiColor.WHITE, new LabColor(0xAAAAAA));
+		colorMap.put(AnsiColor.BRIGHT_BLACK, new LabColor(0x555555));
+		colorMap.put(AnsiColor.BRIGHT_RED, new LabColor(0xFF5555));
+		colorMap.put(AnsiColor.BRIGHT_GREEN, new LabColor(0x55FF00));
+		colorMap.put(AnsiColor.BRIGHT_YELLOW, new LabColor(0xFFFF55));
+		colorMap.put(AnsiColor.BRIGHT_BLUE, new LabColor(0x5555FF));
+		colorMap.put(AnsiColor.BRIGHT_MAGENTA, new LabColor(0xFF55FF));
+		colorMap.put(AnsiColor.BRIGHT_CYAN, new LabColor(0x55FFFF));
+		colorMap.put(AnsiColor.BRIGHT_WHITE, new LabColor(0xFFFFFF));
+		ANSI_COLOR_MAP = Collections.unmodifiableMap(colorMap);
+	}
+
+	private AnsiColors() {
+	}
+
+	public static AnsiColor getClosest(Color color) {
+		return getClosest(new LabColor(color));
+	}
+
+	private static AnsiColor getClosest(LabColor color) {
+		AnsiColor result = null;
+		double resultDistance = Float.MAX_VALUE;
+		for (Entry<AnsiColor, LabColor> entry : ANSI_COLOR_MAP.entrySet()) {
+			double distance = color.getDistance(entry.getValue());
+			if (result == null || distance < resultDistance) {
+				resultDistance = distance;
+				result = entry.getKey();
+			}
+		}
+		return result;
+	}
+
+	/**
+	 * Represents a color stored in LAB form.
+	 */
+	private static final class LabColor {
+
+		private static final ColorSpace XYZ_COLOR_SPACE = ColorSpace
+				.getInstance(ColorSpace.CS_CIEXYZ);
+
+		private final double l;
+
+		private final double a;
+
+		private final double b;
+
+		LabColor(Integer rgb) {
+			this(rgb == null ? (Color) null : new Color(rgb));
+		}
+
+		LabColor(Color color) {
+			Assert.notNull(color, "Color must not be null");
+			float[] lab = fromXyz(color.getColorComponents(XYZ_COLOR_SPACE, null));
+			this.l = lab[0];
+			this.a = lab[1];
+			this.b = lab[2];
+		}
+
+		private float[] fromXyz(float[] xyz) {
+			return fromXyz(xyz[0], xyz[1], xyz[2]);
+		}
+
+		private float[] fromXyz(float x, float y, float z) {
+			double l = (f(y) - 16.0) * 116.0;
+			double a = (f(x) - f(y)) * 500.0;
+			double b = (f(y) - f(z)) * 200.0;
+			return new float[] { (float) l, (float) a, (float) b };
+		}
+
+		private double f(double t) {
+			return (t > (216.0 / 24389.0) ? Math.cbrt(t)
+					: (1.0 / 3.0) * Math.pow(29.0 / 6.0, 2) * t + (4.0 / 29.0));
+		}
+
+		// See http://en.wikipedia.org/wiki/Color_difference#CIE94
+		public double getDistance(LabColor other) {
+			double c1 = Math.sqrt(this.a * this.a + this.b * this.b);
+			double deltaC = c1 - Math.sqrt(other.a * other.a + other.b * other.b);
+			double deltaA = this.a - other.a;
+			double deltaB = this.b - other.b;
+			double deltaH = Math.sqrt(
+					Math.max(0.0, deltaA * deltaA + deltaB * deltaB - deltaC * deltaC));
+			return Math.sqrt(Math.max(0.0,
+					Math.pow((this.l - other.l) / (1.0), 2)
+							+ Math.pow(deltaC / (1 + 0.045 * c1), 2)
+							+ Math.pow(deltaH / (1 + 0.015 * c1), 2.0)));
+		}
+
+	}
+
+}

spring-boot/src/main/java/org/springframework/boot/ansi/AnsiColorsTests.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2012-2016 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
+ *
+ *      http://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 java.awt.Color;
+
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link AnsiColors}.
+ *
+ * @author Phillip Webb
+ */
+public class AnsiColorsTests {
+
+	@Test
+	public void getClosestWhenExactMatchShouldReturnAnsiColor() throws Exception {
+		assertThat(getClosest(0x000000)).isEqualTo(AnsiColor.BLACK);
+		assertThat(getClosest(0xAA0000)).isEqualTo(AnsiColor.RED);
+		assertThat(getClosest(0x00AA00)).isEqualTo(AnsiColor.GREEN);
+		assertThat(getClosest(0xAA5500)).isEqualTo(AnsiColor.YELLOW);
+		assertThat(getClosest(0x0000AA)).isEqualTo(AnsiColor.BLUE);
+		assertThat(getClosest(0xAA00AA)).isEqualTo(AnsiColor.MAGENTA);
+		assertThat(getClosest(0x00AAAA)).isEqualTo(AnsiColor.CYAN);
+		assertThat(getClosest(0xAAAAAA)).isEqualTo(AnsiColor.WHITE);
+		assertThat(getClosest(0x555555)).isEqualTo(AnsiColor.BRIGHT_BLACK);
+		assertThat(getClosest(0xFF5555)).isEqualTo(AnsiColor.BRIGHT_RED);
+		assertThat(getClosest(0x55FF00)).isEqualTo(AnsiColor.BRIGHT_GREEN);
+		assertThat(getClosest(0xFFFF55)).isEqualTo(AnsiColor.BRIGHT_YELLOW);
+		assertThat(getClosest(0x5555FF)).isEqualTo(AnsiColor.BRIGHT_BLUE);
+		assertThat(getClosest(0xFF55FF)).isEqualTo(AnsiColor.BRIGHT_MAGENTA);
+		assertThat(getClosest(0x55FFFF)).isEqualTo(AnsiColor.BRIGHT_CYAN);
+		assertThat(getClosest(0xFFFFFF)).isEqualTo(AnsiColor.BRIGHT_WHITE);
+	}
+
+	@Test
+	public void getClosestWhenCloseShouldReturnAnsiColor() throws Exception {
+		assertThat(getClosest(0x292424)).isEqualTo(AnsiColor.BLACK);
+		assertThat(getClosest(0x8C1919)).isEqualTo(AnsiColor.RED);
+		assertThat(getClosest(0x0BA10B)).isEqualTo(AnsiColor.GREEN);
+		assertThat(getClosest(0xB55F09)).isEqualTo(AnsiColor.YELLOW);
+		assertThat(getClosest(0x0B0BA1)).isEqualTo(AnsiColor.BLUE);
+		assertThat(getClosest(0xA312A3)).isEqualTo(AnsiColor.MAGENTA);
+		assertThat(getClosest(0x0BB5B5)).isEqualTo(AnsiColor.CYAN);
+		assertThat(getClosest(0xBAB6B6)).isEqualTo(AnsiColor.WHITE);
+		assertThat(getClosest(0x615A5A)).isEqualTo(AnsiColor.BRIGHT_BLACK);
+		assertThat(getClosest(0xF23333)).isEqualTo(AnsiColor.BRIGHT_RED);
+		assertThat(getClosest(0x55E80C)).isEqualTo(AnsiColor.BRIGHT_GREEN);
+		assertThat(getClosest(0xF5F54C)).isEqualTo(AnsiColor.BRIGHT_YELLOW);
+		assertThat(getClosest(0x5656F0)).isEqualTo(AnsiColor.BRIGHT_BLUE);
+		assertThat(getClosest(0xFA50FA)).isEqualTo(AnsiColor.BRIGHT_MAGENTA);
+		assertThat(getClosest(0x56F5F5)).isEqualTo(AnsiColor.BRIGHT_CYAN);
+		assertThat(getClosest(0xEDF5F5)).isEqualTo(AnsiColor.BRIGHT_WHITE);
+	}
+
+	private AnsiColor getClosest(int rgb) {
+		return AnsiColors.getClosest(new Color(rgb));
+	}
+
+}

spring-boot/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -13,9 +13,36 @@
   {
     "name": "banner.location",
     "type": "org.springframework.core.io.Resource",
-    "description": "Banner file location.",
+    "description": "Banner text resource location.",
     "defaultValue": "classpath:banner.txt"
   },
+  {
+    "name": "banner.image.location",
+    "type": "org.springframework.core.io.Resource",
+    "description": "Banner image file location.",
+    "defaultValue": "banner.gif"
+  },
+  {
+    "name": "banner.image.width",
+    "type": "java.lang.Integer",
+    "description": "Banner image width (in chars)."
+  },
+  {
+    "name": "banner.image.height",
+    "type": "java.lang.Integer",
+    "description": "Banner image height (in chars)."
+  },
+  {
+    "name": "banner.image.margin",
+    "type": "java.lang.Integer",
+    "description": "Left hand image height (in chars)."
+  },
+  {
+    "name": "banner.image.invert",
+    "type": "java.lang.Boolean",
+    "description": "Invert images for dark console themes.",
+    "defaultValue": false
+  },
   {
     "name": "debug",
     "type": "java.lang.Boolean",

spring-boot/src/test/java/org/springframework/boot/ImageBannerTests.java

@@ -0,0 +1,191 @@
+/*
+ * Copyright 2012-2014 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
+ *
+ *      http://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;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import org.springframework.boot.ansi.AnsiBackground;
+import org.springframework.boot.ansi.AnsiColor;
+import org.springframework.boot.ansi.AnsiOutput;
+import org.springframework.boot.ansi.AnsiOutput.Enabled;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.mock.env.MockEnvironment;
+import org.springframework.test.context.support.TestPropertySourceUtils;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link ImageBanner}.
+ *
+ * @author Craig Burke
+ * @author Phillip Webb
+ */
+public class ImageBannerTests {
+
+	private static final String NEW_LINE = System.getProperty("line.separator");
+
+	private static final char HIGH_LUMINANCE_CHARACTER = ' ';
+
+	private static final char LOW_LUMINANCE_CHARACTER = '@';
+
+	private static final String INVERT_TRUE = "banner.image.invert=true";
+
+	@Before
+	public void setup() {
+		AnsiOutput.setEnabled(AnsiOutput.Enabled.ALWAYS);
+	}
+
+	@After
+	public void cleanup() {
+		AnsiOutput.setEnabled(Enabled.DETECT);
+	}
+
+	@Test
+	public void printBannerShouldResetForegroundAndBackground() {
+		String banner = printBanner("black-and-white.gif");
+		String expected = AnsiOutput.encode(AnsiColor.DEFAULT)
+				+ AnsiOutput.encode(AnsiBackground.DEFAULT);
+		assertThat(banner).startsWith(expected);
+	}
+
+	@Test
+	public void printBannerWhenInvertedShouldResetForegroundAndBackground() {
+		String banner = printBanner("black-and-white.gif", INVERT_TRUE);
+		String expected = AnsiOutput.encode(AnsiColor.DEFAULT)
+				+ AnsiOutput.encode(AnsiBackground.BLACK);
+		assertThat(banner).startsWith(expected);
+	}
+
+	@Test
+	public void printBannerShouldPrintWhiteAsBrightWhiteHighLuminance() {
+		String banner = printBanner("black-and-white.gif");
+		String expected = AnsiOutput.encode(AnsiColor.BRIGHT_WHITE)
+				+ HIGH_LUMINANCE_CHARACTER;
+		assertThat(banner).contains(expected);
+	}
+
+	@Test
+	public void printBannerWhenInvertedShouldPrintWhiteAsBrightWhiteLowLuminance() {
+		String banner = printBanner("black-and-white.gif", INVERT_TRUE);
+		String expected = AnsiOutput.encode(AnsiColor.BRIGHT_WHITE)
+				+ LOW_LUMINANCE_CHARACTER;
+		assertThat(banner).contains(expected);
+	}
+
+	@Test
+	public void printBannerShouldPrintBlackAsBlackLowLuminance() {
+		String banner = printBanner("black-and-white.gif");
+		String expected = AnsiOutput.encode(AnsiColor.BLACK) + LOW_LUMINANCE_CHARACTER;
+		assertThat(banner).contains(expected);
+	}
+
+	@Test
+	public void printBannerWhenInvertedShouldPrintBlackAsBlackHighLuminance() {
+		String banner = printBanner("black-and-white.gif", INVERT_TRUE);
+		String expected = AnsiOutput.encode(AnsiColor.BLACK) + HIGH_LUMINANCE_CHARACTER;
+		assertThat(banner).contains(expected);
+	}
+
+	@Test
+	public void printBannerWhenShouldPrintAllColors() {
+		String banner = printBanner("colors.gif");
+		for (AnsiColor color : AnsiColor.values()) {
+			if (color != AnsiColor.DEFAULT) {
+				assertThat(banner).contains(AnsiOutput.encode(color));
+			}
+		}
+	}
+
+	@Test
+	public void printBannerShouldRenderGradient() throws Exception {
+		AnsiOutput.setEnabled(AnsiOutput.Enabled.NEVER);
+		String banner = printBanner("gradient.gif", "banner.image.width=10",
+				"banner.image.margin=0");
+		System.out.println(banner);
+		assertThat(banner).contains("@#8&o:*.  ");
+	}
+
+	@Test
+	public void printBannerShouldCalculateHeight() throws Exception {
+		String banner = printBanner("large.gif", "banner.image.width=20");
+		assertThat(getBannerHeight(banner)).isEqualTo(10);
+	}
+
+	@Test
+	public void printBannerWhenHasHeightPropertyShouldSetHeight() throws Exception {
+		String banner = printBanner("large.gif", "banner.image.width=20",
+				"banner.image.height=30");
+		assertThat(getBannerHeight(banner)).isEqualTo(30);
+	}
+
+	@Test
+	public void printBannerShouldCapWidthAndCalculateHeight() throws Exception {
+		AnsiOutput.setEnabled(AnsiOutput.Enabled.NEVER);
+		String banner = printBanner("large.gif", "banner.image.margin=0");
+		assertThat(getBannerWidth(banner)).isEqualTo(76);
+		assertThat(getBannerHeight(banner)).isEqualTo(37);
+	}
+
+	@Test
+	public void printBannerShouldPrintMargin() throws Exception {
+		AnsiOutput.setEnabled(AnsiOutput.Enabled.NEVER);
+		String banner = printBanner("large.gif");
+		String[] lines = banner.split(NEW_LINE);
+		for (int i = 2; i < lines.length - 1; i++) {
+			assertThat(lines[i]).startsWith("  @");
+		}
+	}
+
+	@Test
+	public void printBannerWhenHasMarginPropertShouldPrintSizedMargin() throws Exception {
+		AnsiOutput.setEnabled(AnsiOutput.Enabled.NEVER);
+		String banner = printBanner("large.gif", "banner.image.margin=4");
+		String[] lines = banner.split(NEW_LINE);
+		for (int i = 2; i < lines.length - 1; i++) {
+			assertThat(lines[i]).startsWith("    @");
+		}
+	}
+
+	private int getBannerHeight(String banner) {
+		return banner.split(NEW_LINE).length - 3;
+	}
+
+	private int getBannerWidth(String banner) {
+		int width = 0;
+		for (String line : banner.split(NEW_LINE)) {
+			width = Math.max(width, line.length());
+		}
+		return width;
+	}
+
+	private String printBanner(String path, String... properties) {
+		ImageBanner banner = new ImageBanner(new ClassPathResource(path, getClass()));
+		ConfigurableEnvironment environment = new MockEnvironment();
+		TestPropertySourceUtils.addInlinedPropertiesToEnvironment(environment,
+				properties);
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		banner.printBanner(environment, getClass(), new PrintStream(out));
+		return out.toString();
+	}
+
+}

spring-boot/src/test/java/org/springframework/boot/SpringApplicationTests.java

@@ -19,8 +19,10 @@ package org.springframework.boot;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicReference;
 
@@ -65,7 +67,9 @@ import org.springframework.core.env.Environment;
 import org.springframework.core.env.MapPropertySource;
 import org.springframework.core.env.PropertySource;
 import org.springframework.core.env.StandardEnvironment;
+import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.DefaultResourceLoader;
+import org.springframework.core.io.Resource;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.test.context.support.TestPropertySourceUtils;
 import org.springframework.util.StringUtils;
@@ -90,6 +94,7 @@ import static org.mockito.Mockito.verify;
  * @author Christian Dupuis
  * @author Stephane Nicoll
  * @author Jeremy Rickard
+ * @author Craig Burke
  */
 public class SpringApplicationTests {
 
@@ -191,6 +196,29 @@ public class SpringApplicationTests {
 				.startsWith(String.format("Running a Test!%n%n123456"));
 	}
 
+	@Test
+	public void imageBannerAndTextBanner() throws Exception {
+		SpringApplication application = new SpringApplication(ExampleConfig.class);
+		MockResourceLoader resourceLoader = new MockResourceLoader();
+		resourceLoader.addResource("banner.gif", "black-and-white.gif");
+		resourceLoader.addResource("banner.txt", "foobar.txt");
+		application.setWebEnvironment(false);
+		application.setResourceLoader(resourceLoader);
+		application.run();
+		assertThat(this.output.toString()).contains("@@@@").contains("Foo Bar");
+	}
+
+	@Test
+	public void imageBannerLoads() throws Exception {
+		SpringApplication application = new SpringApplication(ExampleConfig.class);
+		MockResourceLoader resourceLoader = new MockResourceLoader();
+		resourceLoader.addResource("banner.gif", "black-and-white.gif");
+		application.setWebEnvironment(false);
+		application.setResourceLoader(resourceLoader);
+		application.run();
+		assertThat(this.output.toString()).contains("@@@@@@");
+	}
+
 	@Test
 	public void logsNoActiveProfiles() throws Exception {
 		SpringApplication application = new SpringApplication(ExampleConfig.class);
@@ -1089,4 +1117,26 @@ public class SpringApplicationTests {
 		}
 
 	}
+
+	private static class MockResourceLoader implements ResourceLoader {
+
+		private final Map<String, Resource> resources = new HashMap<String, Resource>();
+
+		public void addResource(String source, String path) {
+			this.resources.put(source, new ClassPathResource(path, getClass()));
+		}
+
+		@Override
+		public Resource getResource(String path) {
+			Resource resource = this.resources.get(path);
+			return (resource == null ? new ClassPathResource("doesnotexit") : resource);
+		}
+
+		@Override
+		public ClassLoader getClassLoader() {
+			return getClass().getClassLoader();
+		}
+
+	}
+
 }

spring-boot/src/test/resources/org/springframework/boot/foobar.txt

@@ -0,0 +1 @@
+Foo Bar