- Added support for 'uses' directives in generated the module-info.java

- Added a unit test for the uses directive based on the jcache api

Author: Stefan Reek

src/main/java/org/gradlex/javamodule/moduleinfo/ExtraJavaModuleInfoTransform.java

@@ -331,6 +331,9 @@ private byte[] addModuleInfo(ModuleInfo moduleInfo, Map<String, List<String>> pr
         for (String requireName : moduleInfo.requiresStatic) {
             moduleVisitor.visitRequire(requireName, Opcodes.ACC_STATIC_PHASE, null);
         }
+        for (String usesName : moduleInfo.uses) {
+            moduleVisitor.visitUse(usesName.replace('.', '/'));
+        }
         for (Map.Entry<String, List<String>> entry : providers.entrySet()) {
             String name = entry.getKey();
             List<String> implementations = entry.getValue();

src/main/java/org/gradlex/javamodule/moduleinfo/ModuleInfo.java

@@ -32,6 +32,7 @@ public class ModuleInfo extends ModuleSpec {
     final Set<String> requiresTransitive = new LinkedHashSet<>();
     final Set<String> requiresStatic = new LinkedHashSet<>();
     final Set<String> ignoreServiceProviders = new LinkedHashSet<>();
+    final Set<String> uses = new LinkedHashSet<>();
 
     boolean exportAllPackages;
     boolean requireAllDefinedDependencies;
@@ -69,6 +70,13 @@ public void requiresStatic(String requiresStatic) {
         addOrThrow(this.requiresStatic, requiresStatic);
     }
 
+    /**
+     * @param uses corresponds to the directive in a 'module-info.java' file
+     */
+    public void uses(String uses) {
+        addOrThrow(this.uses, uses);
+    }
+
     /**
      * @param ignoreServiceProvider do not transfer service provider to the 'module-info.class'
      */

src/test/groovy/org/gradlex/javamodule/moduleinfo/test/AbstractFunctionalTest.groovy

@@ -385,6 +385,49 @@ abstract class AbstractFunctionalTest extends Specification {
         run().task(':run').outcome == TaskOutcome.SUCCESS
     }
 
+    def "can add 'uses' directives to legacy libraries"() {
+        given:
+        file("src/main/java/org/gradle/sample/app/Main.java") << """
+            package org.gradle.sample.app;
+            
+            import javax.cache.Caching;
+            import javax.cache.CacheManager;
+            
+            public class Main {
+            
+                public static void main(String[] args)  {
+                    CacheManager manager = Caching.getCachingProvider().getCacheManager();
+                    System.out.println(manager.getClass());
+                }
+            
+            }
+        """
+        file("src/main/java/module-info.java") << """
+            module org.gradle.sample.app {               
+                requires cache.api;
+            }
+        """
+        buildFile << """
+            dependencies {
+                implementation("javax.cache:cache-api:1.1.1") 
+                runtimeOnly("com.github.ben-manes.caffeine:caffeine:3.1.2")
+                runtimeOnly("com.github.ben-manes.caffeine:jcache:3.1.2")
+            }
+            
+            extraJavaModuleInfo {               
+                module("javax.cache:cache-api", "cache.api") {
+                    failOnMissingModuleInfo.set(false)
+                    exportAllPackages()
+                    requireAllDefinedDependencies()
+                    uses("javax.cache.spi.CachingProvider")
+                }
+            }
+        """
+
+        expect:
+        run().task(':run').outcome == TaskOutcome.SUCCESS
+    }
+
     def "can merge several jars into one module"() {
         given:
         file("src/main/java/org/gradle/sample/app/Main.java") << """