/**
* Utility for obtaining an implementation of the {@link InjectorFactory} using
- * {@link ServiceLoader}.
+ * {@link ServiceLoader} and for obtaining a {@link SimpleInjector}.
+ *
+ * The builder takes care that the factory and simple injector are built only once.
+ * For test code, make sure to call {@link #setInjectorFactory(InjectorFactory)}
+ * before each test case to force the retrieval of a new factory and injector. This
+ * is important because if the simple injector is not created again it will use
+ * cached {@link Injector} instances from other tests.
*
* @author Erik Brakkee
*/
public class InjectorFactoryBuilder {
+ private static InjectorFactory FACTORY;
+
+ private static SimpleInjector INJECTOR;
+
/**
- * Gets the injector factory by using the first one found using
- * {@link ServiceLoader}.
+ * Sets the injector factory. This is useful for testing.
+ * @param aFactory Factory to use.
+ */
+ public static void setInjectorFactory(InjectorFactory aFactory) {
+ FACTORY = aFactory;
+ INJECTOR = new SimpleInjector(aFactory);
+ }
+
+ /**
+ * Gets the injector factory by using the first one found using
+ * {@link ServiceLoader}.
*
- * @return InjectorFactory.
+ * @return InjectorFactory.
*/
public static InjectorFactory getInjectorFactory() {
+ if (FACTORY == null) {
+ FACTORY = findInjectorFactory();
+ INJECTOR = new SimpleInjector(FACTORY);
+ }
+ return FACTORY;
+ }
+
+ public static SimpleInjector getInjector() {
+ getInjectorFactory();
+ return INJECTOR;
+ }
+
+ /**
+ * Finds the injector factory musing <code>ServiceLoader</code>
+ *
+ * @return InjectorFactory.
+ */
+ private static InjectorFactory findInjectorFactory() {
ServiceLoader<InjectorFactory> factories = ServiceLoader
.load(InjectorFactory.class);
try {