Messaging polyglot support (#1472)

added support for AMQP, KAFKA and standalone options

docker/spring-cloud-contract-docker/project/buildSrc/src/main/java/contracts/DocsFromSources.java

@@ -0,0 +1,160 @@
+/*
+ * Copyright 2013-2020 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 contracts;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.FileVisitResult;
+import java.nio.file.FileVisitor;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+import org.gradle.api.Project;
+import org.jboss.forge.roaster.Roaster;
+import org.jboss.forge.roaster.model.JavaUnit;
+import org.jboss.forge.roaster.model.source.AnnotationSource;
+import org.jboss.forge.roaster.model.source.FieldSource;
+import org.jboss.forge.roaster.model.source.JavaClassSource;
+import org.jboss.forge.roaster.model.source.JavaDocSource;
+
+public class DocsFromSources {
+
+	private static final String ADOC_HEADER =
+			".Docker environment variables - read at runtime\n"
+			+ "|===\n"
+			+ "|Name | Description | Default\n";
+
+	private final Project project;
+
+	public DocsFromSources(Project project) {
+		this.project = project;
+	}
+
+	public void buildApplicationEnvVars() {
+		Path path = new File(rootDir(), sourcePath()).toPath();
+		List<EnvVar> envVars = new ArrayList<>();
+		FileVisitor<Path> fv = new SimpleFileVisitor<Path>() {
+			@Override
+			public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
+					throws IOException {
+				if (!file.toString().endsWith(".java")) {
+					info("Skipping [" + file.toString() + "]");
+					return FileVisitResult.CONTINUE;
+				}
+				JavaUnit unit = Roaster.parseUnit(Files.newInputStream(file));
+				JavaClassSource myClass = unit.getGoverningType();
+				info("Checking [" + myClass.getName() + "]");
+				List<FieldSource<JavaClassSource>> fields = myClass.getFields();
+				for (FieldSource<JavaClassSource> field : fields) {
+					List<AnnotationSource<JavaClassSource>> annotations = field.getAnnotations();
+					for (AnnotationSource<JavaClassSource> annotation : annotations) {
+						if ("org.springframework.beans.factory.annotation.Value".equals(annotation.getQualifiedName())) {
+							info("Field [" + field.getName() + "] has @Value annotation");
+							JavaDocSource<FieldSource<JavaClassSource>> javaDoc = field.getJavaDoc();
+							String description = javaDoc.getFullText();
+							// ${foo:asd}
+							String annotationValue = annotation.getStringValue();
+							// foo:asd
+							annotationValue = annotationValue.substring(2, annotationValue.length() - 1);
+							String[] parsed = annotationValue.split(":");
+							String defaultValue = "";
+							String name = parsed[0];
+							if (parsed.length == 2) {
+								defaultValue = parsed[1];
+							}
+							envVars.add(new EnvVar(name, description, defaultValue));
+						}
+					}
+				}
+				info("Found [" + envVars.size() + "] env var field entries");
+				return FileVisitResult.CONTINUE;
+			}
+		};
+
+		try {
+			Files.walkFileTree(path, fv);
+			Path output = new File(rootDir(), "build/appProps.adoc").toPath();
+			StringBuilder stringBuilder = new StringBuilder().append(ADOC_HEADER);
+			Collections.sort(envVars);
+			envVars.forEach(envVar -> stringBuilder.append(envVar.toString()).append("\n"));
+			stringBuilder.append("|===");
+			Files.write(output, stringBuilder.toString().getBytes());
+		}
+		catch (IOException e) {
+			throw new IllegalStateException(e);
+		}
+	}
+
+	String sourcePath() {
+		return "src/test/java/contracts";
+	}
+
+	File rootDir() {
+		return project.getRootDir();
+	}
+
+	void info(String log) {
+		this.project.getLogger().info(log);
+	}
+}
+
+class EnvVar implements Comparable<EnvVar> {
+	final String name;
+	final String description;
+	final String defaultValue;
+
+	EnvVar(String name, String description, String defaultValue) {
+		this.name = name;
+		this.description = description;
+		this.defaultValue = defaultValue;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (o == null || getClass() != o.getClass()) {
+			return false;
+		}
+		EnvVar envVar = (EnvVar) o;
+		return Objects.equals(name, envVar.name) &&
+				Objects.equals(description, envVar.description) &&
+				Objects.equals(defaultValue, envVar.defaultValue);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(name, description, defaultValue);
+	}
+
+	@Override
+	public int compareTo(EnvVar o) {
+		return name.compareTo(o.name);
+	}
+
+	@Override
+	public String toString() {
+		return "|" + name + "|" + description + "|" + defaultValue;
+	}
+}