Adds a @component annotation.

structurizr-annotation/README.md

@@ -2,3 +2,9 @@
 
 [![Maven Central](https://img.shields.io/maven-central/v/com.structurizr/structurizr-annotation.svg?label=Maven%20Central)](https://search.maven.org/artifact/com.structurizr/structurizr-annotation)
 
+This library defines some custom annotations that you can add to your code.
+These serve to either make it explicit how components should be extracted from your codebase (e.g. `@Component`),
+or they help supplement the software architecture model (e.g. `@Property`, `@Tag`).
+
+- This library has no dependencies.
+- All annotations have a runtime retention policy, so they will be present in the compiled bytecode.

structurizr-annotation/src/main/java/com/structurizr/annotation/Component.java

@@ -0,0 +1,12 @@
+package com.structurizr.annotation;
+
+import java.lang.annotation.*;
+
+/**
+ * A type-level annotation that can be used to indicate the type represents a component.
+ */
+@Documented
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Component {
+}

structurizr-component/src/test/java/com/structurizr/component/matcher/AnnotationTypeMatcherTests.java

@@ -1,5 +1,6 @@
 package com.structurizr.component.matcher;
 
+import com.structurizr.annotation.Component;
 import com.structurizr.component.Type;
 import org.apache.bcel.classfile.ClassParser;
 import org.junit.jupiter.api.Test;
@@ -54,7 +55,7 @@ void matches_ReturnsTrue_WhenThereIsAMatch() throws Exception {
         ClassParser parser = new ClassParser(new File(classes, "com/structurizr/component/matcher/annotationTypeMatcher/CustomerController.class").getAbsolutePath());
         Type type = new Type(parser.parse());
 
-        assertTrue(new AnnotationTypeMatcher("com.structurizr.component.matcher.annotationTypeMatcher.Controller").matches(type));
+        assertTrue(new AnnotationTypeMatcher(Component.class.getName()).matches(type));
     }
 
 }

structurizr-component/src/test/java/com/structurizr/component/matcher/annotationTypeMatcher/CustomerController.java

@@ -1,5 +1,7 @@
 package com.structurizr.component.matcher.annotationTypeMatcher;
 
-@Controller
+import com.structurizr.annotation.Component;
+
+@Component
 public class CustomerController {
 }