do not ever consider Object as a candidate type for autowiring by type (SPR-6600)

Author: jhoeller

org.springframework.beans/src/main/java/org/springframework/beans/factory/support/AbstractAutowireCapableBeanFactory.java

@@ -1124,24 +1124,27 @@ protected void autowireByType(
 		for (String propertyName : propertyNames) {
 			try {
 				PropertyDescriptor pd = bw.getPropertyDescriptor(propertyName);
-				MethodParameter methodParam = BeanUtils.getWriteMethodParameter(pd);
-				// Do not allow eager init for type matching in case of a prioritized post-processor.
-				boolean eager = !PriorityOrdered.class.isAssignableFrom(bw.getWrappedClass());
-				DependencyDescriptor desc = new DependencyDescriptor(methodParam, false, eager);
-
-				Object autowiredArgument = resolveDependency(desc, beanName, autowiredBeanNames, converter);
-				if (autowiredArgument != null) {
-					pvs.add(propertyName, autowiredArgument);
-				}
-				for (String autowiredBeanName : autowiredBeanNames) {
-					registerDependentBean(autowiredBeanName, beanName);
-					if (logger.isDebugEnabled()) {
-						logger.debug(
-								"Autowiring by type from bean name '" + beanName + "' via property '" + propertyName +
-										"' to bean named '" + autowiredBeanName + "'");
+				// Don't try autowiring by type for type Object: never makes sense,
+				// even if it technically is a unsatisfied, non-simple property.
+				if (!Object.class.equals(pd.getPropertyType())) {
+					MethodParameter methodParam = BeanUtils.getWriteMethodParameter(pd);
+					// Do not allow eager init for type matching in case of a prioritized post-processor.
+					boolean eager = !PriorityOrdered.class.isAssignableFrom(bw.getWrappedClass());
+					DependencyDescriptor desc = new DependencyDescriptor(methodParam, false, eager);
+					Object autowiredArgument = resolveDependency(desc, beanName, autowiredBeanNames, converter);
+					if (autowiredArgument != null) {
+						pvs.add(propertyName, autowiredArgument);
+					}
+					for (String autowiredBeanName : autowiredBeanNames) {
+						registerDependentBean(autowiredBeanName, beanName);
+						if (logger.isDebugEnabled()) {
+							logger.debug(
+									"Autowiring by type from bean name '" + beanName + "' via property '" + propertyName +
+											"' to bean named '" + autowiredBeanName + "'");
+						}
 					}
+					autowiredBeanNames.clear();
 				}
-				autowiredBeanNames.clear();
 			}
 			catch (BeansException ex) {
 				throw new UnsatisfiedDependencyException(mbd.getResourceDescription(), beanName, propertyName, ex);