Added setModulesToInstall with convenient Class vararg, renamed setFindModules to setFindModulesViaServiceLoader, made existing setModules override any other setting

Issue: SPR-11040

Author: jhoeller

spring-web/src/main/java/org/springframework/http/converter/json/Jackson2ObjectMapperFactoryBean.java

@@ -114,6 +114,8 @@
  * </bean>
  * </pre>
  *
+ * <p>Tested against Jackson 2.2 and 2.3; compatible with Jackson 2.0 and higher.
+ *
  * @author <a href="mailto:[email protected]">Dmitry Katsubo</a>
  * @author Rossen Stoyanchev
  * @author Brian Clozel
@@ -136,9 +138,11 @@ public class Jackson2ObjectMapperFactoryBean implements FactoryBean<ObjectMapper
 
 	private final Map<Object, Boolean> features = new HashMap<Object, Boolean>();
 
-	private final List<Module> modules = new LinkedList<Module>();
+	private List<Module> modules;
+
+	private Class<? extends Module>[] modulesToInstall;
 
-	private boolean findModules;
+	private boolean findModulesViaServiceLoader;
 
 	private ClassLoader beanClassLoader;
 
@@ -285,26 +289,44 @@ public void setFeaturesToDisable(Object... featuresToDisable) {
 	}
 
 	/**
-	 * Set whether to let Jackson find available modules via the ServiceLoader.
-	 * Requires Jackson 2.2 or higher.
-	 * <p>If this mode is not set, Spring's Jackson2ObjectMapperFactoryBean itself
-	 * will try to find the JSR-310 and Joda-Time support modules on the classpath -
-	 * provided that Java 8 and Joda-Time themselves are available, respectively.
-	 * @see com.fasterxml.jackson.databind.ObjectMapper#findModules()
+	 * Set a complete list of modules to be registered with the {@link ObjectMapper}.
+	 * <p>Note: If this is set, no finding of modules is going to happen - not by
+	 * Jackson, and not by Spring either (see {@link #setFindModulesViaServiceLoader}).
+	 * As a consequence, specifying an empty list here will suppress any kind of
+	 * module detection.
+	 * <p>Specify either this or {@link #setModulesToInstall}, not both.
+	 * @since 4.0
+	 * @see com.fasterxml.jackson.databind.Module
 	 */
-	public void setFindModules(boolean findModules) {
-		this.findModules = findModules;
+	public void setModules(List<Module> modules) {
+		this.modules = new LinkedList<Module>(modules);
 	}
 
 	/**
-	 * Set the list of modules to be registered with the {@link ObjectMapper}.
-	 * @since 4.0
+	 * Specify one or more modules by class (or class name in XML),
+	 * to be registered with the {@link ObjectMapper}.
+	 * <p>Modules specified here will be registered in combination with
+	 * Spring's autodetection of JSR-310 and Joda-Time, or Jackson's
+	 * finding of modules (see {@link #setFindModulesViaServiceLoader}).
+	 * <p>Specify either this or {@link #setModules}, not both.
+	 * @since 4.0.1
 	 * @see com.fasterxml.jackson.databind.Module
 	 */
-	public void setModules(List<Module> modules) {
-		if (modules != null) {
-			this.modules.addAll(modules);
-		}
+	public void setModulesToInstall(Class<? extends Module>... modules) {
+		this.modulesToInstall = modules;
+	}
+
+	/**
+	 * Set whether to let Jackson find available modules via the JDK ServiceLoader,
+	 * based on META-INF metadata in the classpath. Requires Jackson 2.2 or higher.
+	 * <p>If this mode is not set, Spring's Jackson2ObjectMapperFactoryBean itself
+	 * will try to find the JSR-310 and Joda-Time support modules on the classpath -
+	 * provided that Java 8 and Joda-Time themselves are available, respectively.
+	 * @since 4.0.1
+	 * @see com.fasterxml.jackson.databind.ObjectMapper#findModules()
+	 */
+	public void setFindModulesViaServiceLoader(boolean findModules) {
+		this.findModulesViaServiceLoader = findModules;
 	}
 
 	@Override
@@ -342,15 +364,27 @@ public void afterPropertiesSet() {
 			configureFeature(feature, this.features.get(feature));
 		}
 
-		if (this.findModules) {
-			this.objectMapper.registerModules(ObjectMapper.findModules(this.beanClassLoader));
+		if (this.modules != null) {
+			// Complete list of modules given
+			for (Module module : this.modules) {
+				// Using Jackson 2.0+ registerModule method, not Jackson 2.2+ registerModules
+				this.objectMapper.registerModule(module);
+			}
 		}
 		else {
-			registerWellKnownModulesIfAvailable();
-		}
-
-		if (!this.modules.isEmpty()) {
-			this.objectMapper.registerModules(this.modules);
+			// Combination of modules by class names specified and class presence in the classpath
+			if (this.modulesToInstall != null) {
+				for (Class<? extends Module> module : this.modulesToInstall) {
+					this.objectMapper.registerModule(BeanUtils.instantiate(module));
+				}
+			}
+			if (this.findModulesViaServiceLoader) {
+				// Jackson 2.2+
+				this.objectMapper.registerModules(ObjectMapper.findModules(this.beanClassLoader));
+			}
+			else {
+				registerWellKnownModulesIfAvailable();
+			}
 		}
 	}