Provide default ParameterNameDiscoverer for AACBF

Prior to this change, AbstractAutowireCapableBeanFactory did not support
a default ParameterNameDiscoverer.  This meant that attempting to use
<constructor-arg name=".."> syntax would fail (with a fairly obscure
exception) as that feature depends on a ParameterNameDiscoverer to
introspect the constructor arguments.

This lack of a default was originally intended to avoid a dependency on
ASM, but now that (a) .asm is a built-in module and (b) .beans has a
non-optional compile-time dependency on .asm, there is no reason not to
provide this default.

The net effect is that in a number of locations throughout the
framework, namely in GenericApplicationContext and
AbstractRefreshableApplicationContext, it is no longer necessary to
explicitly call AACBF#setParameterNameDiscoverer. This also means that
using a naked BeanFactory (likely for testing scenarios) is that much
easier.

Issue: SPR-8184

git-svn-id: https://src.springframework.org/svn/spring-framework/trunk@4568 50f2f4bb-b051-0410-bef5-90022cba6387

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

@@ -68,6 +68,7 @@ import org.springframework.beans.factory.config.DependencyDescriptor;
 import org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessor;
 import org.springframework.beans.factory.config.SmartInstantiationAwareBeanPostProcessor;
 import org.springframework.beans.factory.config.TypedStringValue;
+import org.springframework.core.LocalVariableTableParameterNameDiscoverer;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.ParameterNameDiscoverer;
 import org.springframework.core.PriorityOrdered;
@@ -116,7 +117,7 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 	private InstantiationStrategy instantiationStrategy = new CglibSubclassingInstantiationStrategy();
 
 	/** Resolver strategy for method parameter names */
-	private ParameterNameDiscoverer parameterNameDiscoverer;
+	private ParameterNameDiscoverer parameterNameDiscoverer = new LocalVariableTableParameterNameDiscoverer();
 
 	/** Whether to automatically try to resolve circular references between beans */
 	private boolean allowCircularReferences = true;
@@ -186,9 +187,7 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 	/**
 	 * Set the ParameterNameDiscoverer to use for resolving method parameter
 	 * names if needed (e.g. for constructor names).
-	 * <p>Default is none. A typical candidate is
-	 * {@link org.springframework.core.LocalVariableTableParameterNameDiscoverer},
-	 * which implies an ASM dependency and hence isn't set as the default.
+	 * <p>The default is {@link LocalVariableTableParameterNameDiscoverer}.
 	 */
 	public void setParameterNameDiscoverer(ParameterNameDiscoverer parameterNameDiscoverer) {
 		this.parameterNameDiscoverer = parameterNameDiscoverer;

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

@@ -1350,7 +1350,6 @@ public class DefaultListableBeanFactoryTests {
 	@Test
 	public void testAutowireBeanByTypeWithTwoMatchesAndParameterNameDiscovery() {
 		DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
-		lbf.setParameterNameDiscoverer(new LocalVariableTableParameterNameDiscoverer());
 		RootBeanDefinition bd = new RootBeanDefinition(TestBean.class);
 		RootBeanDefinition bd2 = new RootBeanDefinition(TestBean.class);
 		lbf.registerBeanDefinition("test", bd);

org.springframework.beans/src/test/java/org/springframework/beans/factory/xml/FactoryMethodTests.java

@@ -107,7 +107,6 @@ public class FactoryMethodTests {
 	@Test
 	public void testFactoryMethodsWithNullValue() {
 		DefaultListableBeanFactory xbf = new DefaultListableBeanFactory();
-		xbf.setParameterNameDiscoverer(new LocalVariableTableParameterNameDiscoverer());
 		XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader(xbf);
 		reader.loadBeanDefinitions(new ClassPathResource("factory-methods.xml", getClass()));
 

org.springframework.beans/src/test/java/org/springframework/beans/factory/xml/SimpleConstructorNamespaceHandlerTests.java

@@ -103,7 +103,7 @@ public class SimpleConstructorNamespaceHandlerTests {
 
 	private XmlBeanFactory createFactory(String resourceName) {
 		XmlBeanFactory fact = new XmlBeanFactory(new ClassPathResource(resourceName, getClass()));
-		fact.setParameterNameDiscoverer(new LocalVariableTableParameterNameDiscoverer());
+		//fact.setParameterNameDiscoverer(new LocalVariableTableParameterNameDiscoverer());
 		return fact;
 	}
 }

org.springframework.context/src/main/java/org/springframework/context/support/AbstractRefreshableApplicationContext.java

@@ -216,7 +216,6 @@ public abstract class AbstractRefreshableApplicationContext extends AbstractAppl
 		if (this.allowCircularReferences != null) {
 			beanFactory.setAllowCircularReferences(this.allowCircularReferences);
 		}
-		beanFactory.setParameterNameDiscoverer(new LocalVariableTableParameterNameDiscoverer());
 		beanFactory.setAutowireCandidateResolver(new QualifierAnnotationAutowireCandidateResolver());
 	}
 

org.springframework.context/src/main/java/org/springframework/context/support/GenericApplicationContext.java

@@ -101,7 +101,6 @@ public class GenericApplicationContext extends AbstractApplicationContext implem
 	 */
 	public GenericApplicationContext() {
 		this.beanFactory = new DefaultListableBeanFactory();
-		this.beanFactory.setParameterNameDiscoverer(new LocalVariableTableParameterNameDiscoverer());
 		this.beanFactory.setAutowireCandidateResolver(new QualifierAnnotationAutowireCandidateResolver());
 	}