Replace static version field with ClassPathResource.

Previously, the default version was loaded from a java constant. This version used to be updated by hand after the release train was published to maven central, then built and deployed by hand. Spring-Cloud-Cli is now built and deployed automatically, but the bom version hasn't been updated.

The constant was replaced with the contents of a file that is updated at build time. This process works for development and release without any manual intervention.

Fixes gh-174

spring-cloud-cli/pom.xml

@@ -15,6 +15,15 @@
 		<version>2.2.4.BUILD-SNAPSHOT</version>
 	</parent>
 
+	<build>
+		<resources>
+			<resource>
+				<directory>src/main/resources</directory>
+				<filtering>true</filtering>
+			</resource>
+		</resources>
+	</build>
+
 	<dependencies>
 		<dependency>
 			<groupId>org.springframework.cloud.launcher</groupId>

spring-cloud-cli/src/main/java/org/springframework/cloud/cli/compiler/SpringCloudBomAstTransformation.java

@@ -16,10 +16,18 @@
 
 package org.springframework.cloud.cli.compiler;
 
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+
 import org.codehaus.groovy.control.CompilePhase;
 import org.codehaus.groovy.transform.GroovyASTTransformation;
 import org.springframework.boot.cli.compiler.DependencyManagementBomTransformation;
 import org.springframework.boot.cli.compiler.GenericBomAstTransformation;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.util.ReflectionUtils;
+import org.springframework.util.StreamUtils;
+import org.springframework.util.StringUtils;
 
 /**
  * @author Dave Syer
@@ -28,11 +36,9 @@ import org.springframework.boot.cli.compiler.GenericBomAstTransformation;
 @GroovyASTTransformation(phase = CompilePhase.CONVERSION)
 public class SpringCloudBomAstTransformation extends GenericBomAstTransformation {
 
-	private static final String SPRING_CLOUD_VERSION = "Hoxton.SR7";
-
 	@Override
 	protected String getBomModule() {
-		return "org.springframework.cloud:spring-cloud-starter-parent:" + SPRING_CLOUD_VERSION;
+		return "org.springframework.cloud:spring-cloud-starter-parent:" + getBomVersion();
 	}
 
 	@Override
@@ -40,4 +46,19 @@ public class SpringCloudBomAstTransformation extends GenericBomAstTransformation
 		return DependencyManagementBomTransformation.ORDER - 50;
 	}
 
+	String getBomVersion() {
+		try (InputStream in = new ClassPathResource("META-INF/springcloudbom-version.txt").getInputStream()) {
+			String version = StreamUtils.copyToString(in, StandardCharsets.UTF_8);
+			if (StringUtils.hasText(version)) {
+				version = version.trim();
+			}
+			return version;
+		}
+		catch (IOException e) {
+			ReflectionUtils.rethrowRuntimeException(e);
+		}
+		// not reachable since exception rethrown at runtime
+		return null;
+	}
+
 }

spring-cloud-cli/src/main/resources/META-INF/springcloudbom-version.txt

@@ -0,0 +1 @@
+@spring-cloud.version@

spring-cloud-cli/src/test/java/org/springframework/cloud/cli/compiler/SpringCloudBomAstTransformationTests.java

@@ -0,0 +1,16 @@
+package org.springframework.cloud.cli.compiler;
+
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class SpringCloudBomAstTransformationTests {
+
+	@Test
+	public void defaultVersionReadFromFile() {
+		String version = new SpringCloudBomAstTransformation().getBomVersion();
+		// starts with one or more word chars then a .
+		// TODO: change to \\d (digits) when merged to master
+		assertThat(version).isNotBlank().doesNotContainAnyWhitespaces().containsPattern("^\\w+\\..*");
+	}
+}

spring-cloud-launcher/spring-cloud-launcher-deployer/src/main/java/org/springframework/cloud/launcher/deployer/DeployerApplication.java

@@ -113,7 +113,11 @@ public class DeployerApplication {
 
 	String getDefaultVersion() {
 		try (InputStream in = new ClassPathResource("META-INF/cli-version.txt").getInputStream()) {
-			return StreamUtils.copyToString(in, StandardCharsets.UTF_8);
+			String version = StreamUtils.copyToString(in, StandardCharsets.UTF_8);
+			if (StringUtils.hasText(version)) {
+				version = version.trim();
+			}
+			return version;
 		}
 		catch (IOException e) {
 			ReflectionUtils.rethrowRuntimeException(e);

spring-cloud-launcher/spring-cloud-launcher-deployer/src/test/java/org/springframework/cloud/launcher/deployer/DeployerApplicationTests.java

@@ -64,6 +64,6 @@ public class DeployerApplicationTests {
 	public void defaultVersionReadFromFile() {
 		String defaultVersion = new DeployerApplication("--launcher.deploy=foo,bar").getDefaultVersion();
 		// starts with one or more digits then a .
-		assertThat(defaultVersion).isNotBlank().containsPattern("^\\d+\\..*");
+		assertThat(defaultVersion).isNotBlank().doesNotContainAnyWhitespaces().containsPattern("^\\d+\\..*");
 	}
 }