DefaultListableBeanFactory only calls getPriority for non-null instance

Issue: SPR-16508

spring-beans/src/main/java/org/springframework/beans/factory/support/DefaultListableBeanFactory.java

@@ -1006,7 +1006,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 				}
 			}
 			if (!autowireCandidates.isEmpty()) {
-				candidateNames = autowireCandidates.toArray(new String[autowireCandidates.size()]);
+				candidateNames = StringUtils.toStringArray(autowireCandidates);
 			}
 		}
 
@@ -1017,8 +1017,9 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 		else if (candidateNames.length > 1) {
 			Map<String, Object> candidates = new LinkedHashMap<>(candidateNames.length);
 			for (String beanName : candidateNames) {
-				if (containsSingleton(beanName)) {
-					candidates.put(beanName, getBean(beanName, requiredType, args));
+				if (containsSingleton(beanName) && args == null) {
+					Object beanInstance = getBean(beanName);
+					candidates.put(beanName, (beanInstance instanceof NullBean ? null : beanInstance));
 				}
 				else {
 					candidates.put(beanName, getType(beanName));
@@ -1030,7 +1031,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 			}
 			if (candidateName != null) {
 				Object beanInstance = candidates.get(candidateName);
-				if (beanInstance instanceof Class) {
+				if (beanInstance == null || beanInstance instanceof Class) {
 					beanInstance = getBean(candidateName, requiredType, args);
 				}
 				return new NamedBeanHolder<>(candidateName, (T) beanInstance);
@@ -1413,23 +1414,25 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 		for (Map.Entry<String, Object> entry : candidates.entrySet()) {
 			String candidateBeanName = entry.getKey();
 			Object beanInstance = entry.getValue();
-			Integer candidatePriority = getPriority(beanInstance);
-			if (candidatePriority != null) {
-				if (highestPriorityBeanName != null) {
-					if (candidatePriority.equals(highestPriority)) {
-						throw new NoUniqueBeanDefinitionException(requiredType, candidates.size(),
-								"Multiple beans found with the same priority ('" + highestPriority +
-								"') among candidates: " + candidates.keySet());
+			if (beanInstance != null) {
+				Integer candidatePriority = getPriority(beanInstance);
+				if (candidatePriority != null) {
+					if (highestPriorityBeanName != null) {
+						if (candidatePriority.equals(highestPriority)) {
+							throw new NoUniqueBeanDefinitionException(requiredType, candidates.size(),
+									"Multiple beans found with the same priority ('" + highestPriority +
+									"') among candidates: " + candidates.keySet());
+						}
+						else if (candidatePriority < highestPriority) {
+							highestPriorityBeanName = candidateBeanName;
+							highestPriority = candidatePriority;
+						}
 					}
-					else if (candidatePriority < highestPriority) {
+					else {
 						highestPriorityBeanName = candidateBeanName;
 						highestPriority = candidatePriority;
 					}
 				}
-				else {
-					highestPriorityBeanName = candidateBeanName;
-					highestPriority = candidatePriority;
-				}
 			}
 		}
 		return highestPriorityBeanName;

spring-beans/src/test/java/org/springframework/beans/factory/DefaultListableBeanFactoryTests.java

@@ -1434,7 +1434,7 @@ public class DefaultListableBeanFactoryTests {
 	}
 
 	@Test
-	public void testGetBeanByTypeWithPrimary() throws Exception {
+	public void testGetBeanByTypeWithPrimary() {
 		DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
 		RootBeanDefinition bd1 = new RootBeanDefinition(TestBean.class);
 		bd1.setLazyInit(true);
@@ -1448,7 +1448,7 @@ public class DefaultListableBeanFactoryTests {
 	}
 
 	@Test
-	public void testGetBeanByTypeWithMultiplePrimary() throws Exception {
+	public void testGetBeanByTypeWithMultiplePrimary() {
 		DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
 		RootBeanDefinition bd1 = new RootBeanDefinition(TestBean.class);
 		bd1.setPrimary(true);
@@ -1462,19 +1462,39 @@ public class DefaultListableBeanFactoryTests {
 	}
 
 	@Test
-	public void testGetBeanByTypeWithPriority() throws Exception {
+	public void testGetBeanByTypeWithPriority() {
 		DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
 		lbf.setDependencyComparator(AnnotationAwareOrderComparator.INSTANCE);
 		RootBeanDefinition bd1 = new RootBeanDefinition(HighPriorityTestBean.class);
 		RootBeanDefinition bd2 = new RootBeanDefinition(LowPriorityTestBean.class);
+		RootBeanDefinition bd3 = new RootBeanDefinition(NullTestBeanFactoryBean.class);
 		lbf.registerBeanDefinition("bd1", bd1);
 		lbf.registerBeanDefinition("bd2", bd2);
+		lbf.registerBeanDefinition("bd3", bd3);
+		lbf.preInstantiateSingletons();
 		TestBean bean = lbf.getBean(TestBean.class);
 		assertThat(bean.getBeanName(), equalTo("bd1"));
 	}
 
 	@Test
-	public void testGetBeanByTypeWithMultiplePriority() throws Exception {
+	public void testMapInjectionWithPriority() {
+		DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
+		lbf.setDependencyComparator(AnnotationAwareOrderComparator.INSTANCE);
+		RootBeanDefinition bd1 = new RootBeanDefinition(HighPriorityTestBean.class);
+		RootBeanDefinition bd2 = new RootBeanDefinition(LowPriorityTestBean.class);
+		RootBeanDefinition bd3 = new RootBeanDefinition(NullTestBeanFactoryBean.class);
+		RootBeanDefinition bd4 = new RootBeanDefinition(TestBeanRecipient.class, RootBeanDefinition.AUTOWIRE_CONSTRUCTOR, false);
+		lbf.registerBeanDefinition("bd1", bd1);
+		lbf.registerBeanDefinition("bd2", bd2);
+		lbf.registerBeanDefinition("bd3", bd3);
+		lbf.registerBeanDefinition("bd4", bd4);
+		lbf.preInstantiateSingletons();
+		TestBean bean = lbf.getBean(TestBeanRecipient.class).testBean;
+		assertThat(bean.getBeanName(), equalTo("bd1"));
+	}
+
+	@Test
+	public void testGetBeanByTypeWithMultiplePriority() {
 		DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
 		lbf.setDependencyComparator(AnnotationAwareOrderComparator.INSTANCE);
 		RootBeanDefinition bd1 = new RootBeanDefinition(HighPriorityTestBean.class);
@@ -1483,12 +1503,12 @@ public class DefaultListableBeanFactoryTests {
 		lbf.registerBeanDefinition("bd2", bd2);
 		thrown.expect(NoUniqueBeanDefinitionException.class);
 		thrown.expectMessage(containsString("Multiple beans found with the same priority"));
-		thrown.expectMessage(containsString("5")); // conflicting priority
+		thrown.expectMessage(containsString("5"));  // conflicting priority
 		lbf.getBean(TestBean.class);
 	}
 
 	@Test
-	public void testGetBeanByTypeWithPriorityAndNullInstance() throws Exception {
+	public void testGetBeanByTypeWithPriorityAndNullInstance() {
 		DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
 		lbf.setDependencyComparator(AnnotationAwareOrderComparator.INSTANCE);
 		RootBeanDefinition bd1 = new RootBeanDefinition(HighPriorityTestBean.class);
@@ -1500,7 +1520,7 @@ public class DefaultListableBeanFactoryTests {
 	}
 
 	@Test
-	public void testGetBeanByTypePrimaryHasPrecedenceOverPriority() throws Exception {
+	public void testGetBeanByTypePrimaryHasPrecedenceOverPriority() {
 		DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
 		lbf.setDependencyComparator(AnnotationAwareOrderComparator.INSTANCE);
 		RootBeanDefinition bd1 = new RootBeanDefinition(HighPriorityTestBean.class);
@@ -1522,7 +1542,7 @@ public class DefaultListableBeanFactoryTests {
 
 		lbf.registerBeanDefinition("bd1", bd1);
 		lbf.registerBeanDefinition("na1", na1);
-		TestBean actual = lbf.getBean(TestBean.class); // na1 was filtered
+		TestBean actual = lbf.getBean(TestBean.class);  // na1 was filtered
 		assertSame(lbf.getBean("bd1", TestBean.class), actual);
 
 		lbf.registerBeanDefinition("bd2", bd2);
@@ -1605,7 +1625,7 @@ public class DefaultListableBeanFactoryTests {
 
 		lbf.registerBeanDefinition("bd1", bd1);
 		lbf.registerBeanDefinition("na1", na1);
-		ConstructorDependency actual = lbf.getBean(ConstructorDependency.class, 42); // na1 was filtered
+		ConstructorDependency actual = lbf.getBean(ConstructorDependency.class, 42);  // na1 was filtered
 		assertThat(actual.beanName, equalTo("bd1"));
 
 		lbf.registerBeanDefinition("bd2", bd2);
@@ -1850,7 +1870,7 @@ public class DefaultListableBeanFactoryTests {
 			// expected
 			assertNotNull("Exception should have cause", ex.getCause());
 			assertEquals("Wrong cause type", NoUniqueBeanDefinitionException.class, ex.getCause().getClass());
-			assertTrue(ex.getMessage().contains("5")); // conflicting priority
+			assertTrue(ex.getMessage().contains("5"));  // conflicting priority
 		}
 	}
 
@@ -2278,7 +2298,7 @@ public class DefaultListableBeanFactoryTests {
 
 	/**
 	 * @Test
-	 * public void testPrototypeCreationIsFastEnough2() throws Exception {
+	 * public void testPrototypeCreationIsFastEnough2() {
 	 * if (factoryLog.isTraceEnabled() || factoryLog.isDebugEnabled()) {
 	 * // Skip this test: Trace logging blows the time limit.
 	 * return;
@@ -2576,7 +2596,7 @@ public class DefaultListableBeanFactoryTests {
 	}
 
 	@Test(expected = IllegalStateException.class)
-	public void testScopingBeanToUnregisteredScopeResultsInAnException() throws Exception {
+	public void testScopingBeanToUnregisteredScopeResultsInAnException() {
 		BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(TestBean.class);
 		AbstractBeanDefinition beanDefinition = builder.getBeanDefinition();
 		beanDefinition.setScope("he put himself so low could hardly look me in the face");
@@ -2587,7 +2607,7 @@ public class DefaultListableBeanFactoryTests {
 	}
 
 	@Test
-	public void testExplicitScopeInheritanceForChildBeanDefinitions() throws Exception {
+	public void testExplicitScopeInheritanceForChildBeanDefinitions() {
 		String theChildScope = "bonanza!";
 
 		RootBeanDefinition parent = new RootBeanDefinition();
@@ -2606,7 +2626,7 @@ public class DefaultListableBeanFactoryTests {
 	}
 
 	@Test
-	public void testScopeInheritanceForChildBeanDefinitions() throws Exception {
+	public void testScopeInheritanceForChildBeanDefinitions() {
 		RootBeanDefinition parent = new RootBeanDefinition();
 		parent.setScope("bonanza!");
 
@@ -2993,7 +3013,7 @@ public class DefaultListableBeanFactoryTests {
 		}
 
 		@Override
-		public T call() throws Exception {
+		public T call() {
 			throw new IllegalStateException();
 		}
 	}
@@ -3004,7 +3024,7 @@ public class DefaultListableBeanFactoryTests {
 		public boolean initialized = false;
 
 		@Override
-		public Object getObject() throws Exception {
+		public Object getObject() {
 			this.initialized = true;
 			return "";
 		}
@@ -3026,7 +3046,7 @@ public class DefaultListableBeanFactoryTests {
 		public boolean initialized = false;
 
 		@Override
-		public Object getObject() throws Exception {
+		public Object getObject() {
 			this.initialized = true;
 			return "";
 		}
@@ -3258,7 +3278,7 @@ public class DefaultListableBeanFactoryTests {
 	private static class NullTestBeanFactoryBean<T> implements FactoryBean<TestBean> {
 
 		@Override
-		public TestBean getObject() throws Exception {
+		public TestBean getObject() {
 			return null;
 		}
 
@@ -3274,6 +3294,16 @@ public class DefaultListableBeanFactoryTests {
 	}
 
 
+	private static class TestBeanRecipient {
+
+		public TestBean testBean;
+
+		public TestBeanRecipient(TestBean testBean) {
+			this.testBean = testBean;
+		}
+	}
+
+
 	enum NonPublicEnum {
 
 		VALUE_1, VALUE_2;