#237 - ENH: Support custom class loader like: BeanScope.builder().classLoader(customClassLoader)

Author: rbygrave

inject-test/src/test/java/org/example/coffee/ClassLoaderTest.java

@@ -0,0 +1,21 @@
+package org.example.coffee;
+
+import io.avaje.inject.BeanScope;
+import org.example.coffee.provider.ProvOther;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class ClassLoaderTest {
+
+  @Test
+  void testUsingClassLoader() {
+    try (BeanScope context = BeanScope.builder()
+      .classLoader(Thread.currentThread().getContextClassLoader())
+      .build()) {
+      ProvOther bean = context.get(ProvOther.class);
+      String other = bean.other();
+      assertThat(other).isEqualTo("mush mush beans");
+    }
+  }
+}

inject/src/main/java/io/avaje/inject/BeanScopeBuilder.java

@@ -212,6 +212,13 @@ default <D> BeanScopeBuilder withBean(Type type, D bean) {
     return bean(type, bean);
   }
 
+  /**
+   * Set the ClassLoader to use when loading modules.
+   *
+   * @param classLoader The ClassLoader to use
+   */
+  BeanScopeBuilder classLoader(ClassLoader classLoader);
+
   /**
    * Use the given BeanScope as the parent. This becomes an additional
    * source of beans that can be wired and accessed in this scope.

inject/src/main/java/io/avaje/inject/DBeanScopeBuilder.java

@@ -4,6 +4,7 @@
 import io.avaje.inject.spi.EnrichBean;
 import io.avaje.inject.spi.Module;
 import io.avaje.inject.spi.SuppliedBean;
+import io.avaje.lang.NonNullApi;
 import io.avaje.lang.Nullable;
 
 import java.lang.System.Logger.Level;
@@ -14,21 +15,20 @@
 /**
  * Build a bean scope with options for shutdown hook and supplying test doubles.
  */
+@NonNullApi
 class DBeanScopeBuilder implements BeanScopeBuilder.ForTesting {
 
   private static final System.Logger log = System.getLogger("io.avaje.inject");
 
   @SuppressWarnings("rawtypes")
   private final List<SuppliedBean> suppliedBeans = new ArrayList<>();
-
   @SuppressWarnings("rawtypes")
   private final List<EnrichBean> enrichBeans = new ArrayList<>();
-
   private final Set<Module> includeModules = new LinkedHashSet<>();
-
   private BeanScope parent;
   private boolean parentOverride = true;
   private boolean shutdownHook;
+  private ClassLoader classLoader;
 
   /**
    * Create a BeanScopeBuilder to ultimately load and return a new BeanScope.
@@ -83,6 +83,12 @@ public <D> BeanScopeBuilder bean(@Nullable String name, Type type, D bean) {
     return this;
   }
 
+  @Override
+  public BeanScopeBuilder classLoader(ClassLoader classLoader) {
+    this.classLoader = classLoader;
+    return this;
+  }
+
   @Override
   public BeanScopeBuilder parent(BeanScope parent) {
     this.parent = parent;
@@ -139,7 +145,8 @@ public BeanScope build() {
     // sort factories by dependsOn
     FactoryOrder factoryOrder = new FactoryOrder(parent, includeModules, !suppliedBeans.isEmpty());
     if (factoryOrder.isEmpty()) {
-      ServiceLoader.load(Module.class).forEach(factoryOrder::add);
+      var loader = classLoader != null ? classLoader : Thread.currentThread().getContextClassLoader();
+      ServiceLoader.load(Module.class, loader).forEach(factoryOrder::add);
     }
 
     Set<String> moduleNames = factoryOrder.orderFactories();
@@ -277,7 +284,7 @@ private void processQueue() {
         }
         sb.append(" - none of the loaded modules ").append(moduleNames).append(" have this in their @InjectModule( provides = ... ). ");
         if (parent != null) {
-          sb.append("The parent BeanScope " + parent + " also does not provide this dependency. ");
+          sb.append("The parent BeanScope ").append(parent).append(" also does not provide this dependency. ");
         }
         sb.append("Either @InjectModule requires/provides are not aligned? or add external dependencies via BeanScopeBuilder.bean()?");
         throw new IllegalStateException(sb.toString());