4.x: Metadata module and loading of files compatible with single jars (helidon-io#10660)

* Introduced Helidon metadata module.
Updated all places where we read metadata files to use the new module.
Support for manifest file or classpath scanning depending on deployment "shape"

* Fix for windows - make sure we use / in location.

* Simplified implementation, removed customization.

* Fixes to updated behavior.

* Fixed build issue - wrong javadoc.

* Update to classpath scanning to avoid problems with closed jar file system.
Updated packaging test to use fat jar (only SE-1)

* Add debug for troubleshooting.

* Fix pattern to pick up integration tests.

* Removed troubleshooting log config.

* Added fat jar tests to SE inject.
Updated MP packaging tests to run no tests in the fat jar profile.

* Update comments and javadocs

---------

Co-authored-by: Romain Grecourt <romain.grecourt@oracle.com>

Author: tomas-langer

.github/workflows/validate.yml

@@ -315,7 +315,7 @@ jobs:
     strategy:
       matrix:
         os: [ ubuntu-22.04, macos-14, windows-2022 ]
-        packaging: [ jar, jlink ]
+        packaging: [ jar, jlink, fat-jar ]
         include:
           - { os: ubuntu-22.04, platform: linux }
           - { os: macos-14, platform: macos }

all/pom.xml

@@ -1273,6 +1273,10 @@
             <groupId>io.helidon.declarative</groupId>
             <artifactId>helidon-declarative-codegen</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.helidon.metadata</groupId>
+            <artifactId>helidon-metadata</artifactId>
+        </dependency>
         <dependency>
             <groupId>io.helidon.metadata</groupId>
             <artifactId>helidon-metadata-hson</artifactId>

bom/pom.xml

@@ -1721,6 +1721,11 @@
             </dependency>
 
             <!-- Metadata -->
+            <dependency>
+                <groupId>io.helidon.metadata</groupId>
+                <artifactId>helidon-metadata</artifactId>
+                <version>${helidon.version}</version>
+            </dependency>
             <dependency>
                 <groupId>io.helidon.metadata</groupId>
                 <artifactId>helidon-metadata-hson</artifactId>

builder/codegen/src/main/java/io/helidon/builder/codegen/BuilderCodegen.java

@@ -46,6 +46,7 @@
 import io.helidon.common.types.Modifier;
 import io.helidon.common.types.TypeInfo;
 import io.helidon.common.types.TypeName;
+import io.helidon.metadata.MetadataConstants;
 
 import static io.helidon.builder.codegen.Types.RUNTIME_PROTOTYPE;
 
@@ -319,7 +320,11 @@ private static void generateCustomMethods(ClassModel.Builder classModel,
 
     private void updateServiceLoaderResource() {
         CodegenFiler filer = ctx.filer();
-        FilerTextResource serviceLoaderResource = filer.textResource("META-INF/helidon/service.loader");
+        String moduleName = ctx.moduleName().orElse(null);
+        String resourceLocation = MetadataConstants.LOCATION
+                + (moduleName == null ? "" : "/" + moduleName)
+                + "/" + MetadataConstants.SERVICE_LOADER_FILE;
+        FilerTextResource serviceLoaderResource = filer.textResource(resourceLocation);
         List<String> lines = new ArrayList<>(serviceLoaderResource.lines());
         if (lines.isEmpty()) {
             lines.add("# List of service contracts we want to support either from service registry, or from service loader");
@@ -335,6 +340,8 @@ private void updateServiceLoaderResource() {
         if (modified) {
             serviceLoaderResource.lines(lines);
             serviceLoaderResource.write();
+            filer.manifest()
+                    .add(resourceLocation);
         }
     }
 

builder/codegen/src/main/java/module-info.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, 2024 Oracle and/or its affiliates.
+ * Copyright (c) 2023, 2025 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,7 @@
     requires io.helidon.common.types;
     requires io.helidon.codegen;
     requires io.helidon.codegen.classmodel;
+    requires io.helidon.metadata;
 
     exports io.helidon.builder.codegen;
 

codegen/apt/pom.xml

@@ -32,6 +32,10 @@
     </description>
 
     <dependencies>
+        <dependency>
+            <groupId>io.helidon.common</groupId>
+            <artifactId>helidon-common</artifactId>
+        </dependency>
         <dependency>
             <groupId>io.helidon.common</groupId>
             <artifactId>helidon-common-types</artifactId>

codegen/apt/src/main/java/io/helidon/codegen/apt/AptContextImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, 2024 Oracle and/or its affiliates.
+ * Copyright (c) 2023, 2025 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -70,11 +70,12 @@ static AptContextImpl create(ProcessingEnvironment env, Set<Option<?>> supported
 
         CodegenScope scope = guessScope(env, options);
         Optional<ModuleInfo> module = findModule(env.getFiler());
+        AptFiler filer = new AptFiler(env, options);
 
         return new AptContextImpl(env,
                                   options,
                                   supportedOptions,
-                                  new AptFiler(env, options),
+                                  filer,
                                   new AptLogger(env, options),
                                   scope,
                                   module.orElse(null));

codegen/apt/src/main/java/io/helidon/codegen/apt/AptFiler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, 2024 Oracle and/or its affiliates.
+ * Copyright (c) 2023, 2025 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -39,14 +39,17 @@
 import io.helidon.codegen.FilerResource;
 import io.helidon.codegen.FilerTextResource;
 import io.helidon.codegen.IndentType;
+import io.helidon.codegen.ManifestResource;
 import io.helidon.codegen.classmodel.ClassModel;
+import io.helidon.common.LazyValue;
 import io.helidon.common.types.TypeName;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
 
 class AptFiler implements CodegenFiler {
     private final Filer filer;
     private final String indent;
+    private final LazyValue<ManifestResource> manifestResource;
 
     AptFiler(ProcessingEnvironment env, CodegenOptions options) {
         this.filer = env.getFiler();
@@ -55,6 +58,7 @@ class AptFiler implements CodegenFiler {
         int codegenRepeat = CodegenOptions.INDENT_COUNT.value(options);
 
         this.indent = String.valueOf(value.character()).repeat(codegenRepeat);
+        this.manifestResource = LazyValue.create(() -> ManifestResource.create(this));
     }
 
     @Override
@@ -141,6 +145,11 @@ public FilerResource resource(String location, Object... originatingElements) {
         }
     }
 
+    @Override
+    public ManifestResource manifest() {
+        return manifestResource.get();
+    }
+
     private Object originatingElement(Element[] elements, Object alternative) {
         if (elements.length == 0) {
             return alternative;

codegen/apt/src/main/java/io/helidon/codegen/apt/AptProcessor.java

@@ -128,6 +128,7 @@ private boolean doProcess(Set<? extends TypeElement> annotations, RoundEnvironme
 
         if (roundEnv.processingOver()) {
             codegen.processingOver();
+            ctx.filer().manifest().write();
             return annotations.isEmpty();
         }
 

codegen/codegen/pom.xml

@@ -39,6 +39,10 @@
             <groupId>io.helidon.common</groupId>
             <artifactId>helidon-common-types</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.helidon.metadata</groupId>
+            <artifactId>helidon-metadata</artifactId>
+        </dependency>
         <dependency>
             <groupId>io.helidon.codegen</groupId>
             <artifactId>helidon-codegen-class-model</artifactId>