Add support for using ${application.title} in startup banners

This commit introduces a new property, application.title, that can
be used in a banner. Its value is resolved from the application
manifest's Implementation-Title attribute.

Closes gh-4603

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

@@ -60,7 +60,8 @@ You can use the following variables inside your `banner.txt` file:
 | Variable | Description
 
 |`${application.version}`
-|The version number of your application as declared in `MANIFEST.MF`. For example `Implementation-Version: 1.0` is printed as `1.0`.
+|The version number of your application as declared in `MANIFEST.MF`. For example
+`Implementation-Version: 1.0` is printed as `1.0`.
 
 |`${application.formatted-version}`
 |The version number of your application as declared in `MANIFEST.MF` formatted for
@@ -76,6 +77,10 @@ brackets and prefixed with `v`). For example `(v{spring-boot-version})`.
 |`${Ansi.NAME}` (or `${AnsiColor.NAME}`, `${AnsiBackground.NAME}`, `${AnsiStyle.NAME}`)
 |Where `NAME` is the name of an ANSI escape code. See
 {sc-spring-boot}/ansi/AnsiPropertySource.{sc-ext}[`AnsiPropertySource`] for details.
+
+|`${application.title}`
+|The title of your application as declared in `MANIFEST.MF`. For example
+`Implementation-Title: MyApp` is printed as `MyApp`.
 |===
 
 TIP: The `SpringApplication.setBanner(...)` method can be used if you want to generate

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

@@ -19,6 +19,7 @@ package org.springframework.boot;
 import java.io.PrintStream;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -40,6 +41,7 @@ import org.springframework.util.StreamUtils;
  * Banner implementation that prints from a source {@link Resource}.
  *
  * @author Phillip Webb
+ * @author Vedran Pavic
  * @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(getTitleResolver(sourceClass));
 		return resolvers;
 	}
 
@@ -124,4 +127,18 @@ public class ResourceBanner implements Banner {
 		return new PropertySourcesPropertyResolver(sources);
 	}
 
+	private PropertyResolver getTitleResolver(Class<?> sourceClass) {
+		MutablePropertySources sources = new MutablePropertySources();
+		String applicationTitle = getApplicationTitle(sourceClass);
+		Map<String, Object> titleMap = Collections.<String, Object>singletonMap(
+				"application.title", (applicationTitle == null ? "" : applicationTitle));
+		sources.addFirst(new MapPropertySource("title", titleMap));
+		return new PropertySourcesPropertyResolver(sources);
+	}
+
+	protected String getApplicationTitle(Class<?> sourceClass) {
+		Package sourcePackage = (sourceClass == null ? null : sourceClass.getPackage());
+		return (sourcePackage == null ? null : sourcePackage.getImplementationTitle());
+	}
+
 }

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

@@ -39,6 +39,7 @@ import static org.junit.Assert.assertThat;
  * Tests for {@link ResourceBanner}.
  *
  * @author Phillip Webb
+ * @author Vedran Pavic
  */
 public class ResourceBannerTests {
 
@@ -51,7 +52,7 @@ public class ResourceBannerTests {
 	public void renderVersions() throws Exception {
 		Resource resource = new ByteArrayResource(
 				"banner ${a} ${spring-boot.version} ${application.version}".getBytes());
-		String banner = printBanner(resource, "10.2", "2.0");
+		String banner = printBanner(resource, "10.2", "2.0", null);
 		assertThat(banner, startsWith("banner 1 10.2 2.0"));
 	}
 
@@ -59,7 +60,7 @@ public class ResourceBannerTests {
 	public void renderWithoutVersions() throws Exception {
 		Resource resource = new ByteArrayResource(
 				"banner ${a} ${spring-boot.version} ${application.version}".getBytes());
-		String banner = printBanner(resource, null, null);
+		String banner = printBanner(resource, null, null, null);
 		assertThat(banner, startsWith("banner 1  "));
 	}
 
@@ -68,7 +69,7 @@ public class ResourceBannerTests {
 		Resource resource = new ByteArrayResource(
 				"banner ${a}${spring-boot.formatted-version}${application.formatted-version}"
 						.getBytes());
-		String banner = printBanner(resource, "10.2", "2.0");
+		String banner = printBanner(resource, "10.2", "2.0", null);
 		assertThat(banner, startsWith("banner 1 (v10.2) (v2.0)"));
 	}
 
@@ -77,7 +78,7 @@ public class ResourceBannerTests {
 		Resource resource = new ByteArrayResource(
 				"banner ${a}${spring-boot.formatted-version}${application.formatted-version}"
 						.getBytes());
-		String banner = printBanner(resource, null, null);
+		String banner = printBanner(resource, null, null, null);
 		assertThat(banner, startsWith("banner 1"));
 	}
 
@@ -86,7 +87,7 @@ public class ResourceBannerTests {
 		Resource resource = new ByteArrayResource(
 				"${Ansi.RED}This is red.${Ansi.NORMAL}".getBytes());
 		AnsiOutput.setEnabled(AnsiOutput.Enabled.ALWAYS);
-		String banner = printBanner(resource, null, null);
+		String banner = printBanner(resource, null, null, null);
 		assertThat(banner, startsWith("\u001B[31mThis is red.\u001B[0m"));
 	}
 
@@ -95,14 +96,30 @@ public class ResourceBannerTests {
 		Resource resource = new ByteArrayResource(
 				"${Ansi.RED}This is red.${Ansi.NORMAL}".getBytes());
 		AnsiOutput.setEnabled(AnsiOutput.Enabled.NEVER);
-		String banner = printBanner(resource, null, null);
+		String banner = printBanner(resource, null, null, null);
 		assertThat(banner, startsWith("This is red."));
 	}
 
+	@Test
+	public void renderWithTitle() throws Exception {
+		Resource resource = new ByteArrayResource(
+				"banner ${application.title} ${a}".getBytes());
+		String banner = printBanner(resource, null, null, "title");
+		assertThat(banner, startsWith("banner title 1"));
+	}
+
+	@Test
+	public void renderWithoutTitle() throws Exception {
+		Resource resource = new ByteArrayResource(
+				"banner ${application.title} ${a}".getBytes());
+		String banner = printBanner(resource, null, null, null);
+		assertThat(banner, startsWith("banner  1"));
+	}
+
 	private String printBanner(Resource resource, String bootVersion,
-			String applicationVersion) {
+			String applicationVersion, String applicationTitle) {
 		ResourceBanner banner = new MockResourceBanner(resource, bootVersion,
-				applicationVersion);
+				applicationVersion, applicationTitle);
 		ConfigurableEnvironment environment = new MockEnvironment();
 		Map<String, Object> source = Collections.<String, Object>singletonMap("a", "1");
 		environment.getPropertySources().addLast(new MapPropertySource("map", source));
@@ -117,11 +134,14 @@ public class ResourceBannerTests {
 
 		private final String applicationVersion;
 
+		private final String applicationTitle;
+
 		MockResourceBanner(Resource resource, String bootVersion,
-				String applicationVersion) {
+				String applicationVersion, String applicationTitle) {
 			super(resource);
 			this.bootVersion = bootVersion;
 			this.applicationVersion = applicationVersion;
+			this.applicationTitle = applicationTitle;
 		}
 
 		@Override
@@ -134,6 +154,11 @@ public class ResourceBannerTests {
 			return this.applicationVersion;
 		}
 
+		@Override
+		protected String getApplicationTitle(Class<?> sourceClass) {
+			return this.applicationTitle;
+		}
+
 	}
 
 }