Allow class-relative resource loading in GenericXmlApplicationContext (SPR-7530)

Before:

    - new GenericXmlApplicationContext("com/acme/path/to/resource.xml");

    - GenericXmlApplicationContext ctx = new GenericXmlApplicationContext();
      ctx.load("com/acme/path/to/resource.xml");
      ctx.refresh();

After:

    - The above remain supported, as well as new class-relative variants

    - import com.acme.path.to.Foo;
      new GenericXmlApplicationContext(Foo.class, "resource.xml");

    - import com.acme.path.to.Foo;
      GenericXmlApplicationContext ctx = new GenericXmlApplicationContext();
      ctx.load(Foo.class, "resource.xml");
      ctx.refresh();

These changes are generally aligned with signatures long available in
ClassPathXmlApplicationContext. As GenericXmlApplicationContext is
intended to be a more flexible successor to CPXAC (and FSXAC), it's
important that all the same conveniences are available.

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

@@ -17,6 +17,7 @@
 package org.springframework.context.support;
 
 import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
+import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
 
 /**
@@ -30,6 +31,7 @@ import org.springframework.core.io.Resource;
  * deliberately override certain bean definitions via an extra configuration file.
  *
  * @author Juergen Hoeller
+ * @author Chris Beams
  * @since 3.0
  * @see #load
  * @see XmlBeanDefinitionReader
@@ -67,6 +69,17 @@ public class GenericXmlApplicationContext extends GenericApplicationContext {
 		refresh();
 	}
 
+	/**
+	 * Create a new GenericXmlApplicationContext, loading bean definitions
+	 * from the given resource locations and automatically refreshing the context.
+	 * @param relativeClass class whose package will be used as a prefix when
+	 * loading each specified resource name
+	 * @param resourceNames relatively-qualified names of resources to load
+	 */
+	public GenericXmlApplicationContext(Class<?> relativeClass, String... resourceNames) {
+		load(relativeClass, resourceNames);
+		refresh();
+	}
 
 	/**
 	 * Set whether to use XML validation. Default is <code>true</code>.
@@ -92,4 +105,18 @@ public class GenericXmlApplicationContext extends GenericApplicationContext {
 		this.reader.loadBeanDefinitions(resourceLocations);
 	}
 
+	/**
+	 * Load bean definitions from the given XML resources.
+	 * @param relativeClass class whose package will be used as a prefix when
+	 * loading each specified resource name
+	 * @param resourceNames relatively-qualified names of resources to load
+	 */
+	public void load(Class<?> relativeClass, String... resourceNames) {
+		Resource[] resources = new Resource[resourceNames.length];
+		for (int i = 0; i < resourceNames.length; i++) {
+			resources[i] = new ClassPathResource(resourceNames[i], relativeClass);
+		}
+		this.load(resources);
+	}
+
 }

org.springframework.context/src/test/java/org/springframework/context/support/GenericXmlApplicationContextTests-context.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+		xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
+
+	<bean id="testBean" class="java.lang.Object"/>
+
+</beans>

org.springframework.context/src/test/java/org/springframework/context/support/GenericXmlApplicationContextTests.java

+package org.springframework.context.support;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+
+import org.junit.Test;
+import org.springframework.context.ApplicationContext;
+import org.springframework.util.ClassUtils;
+
+/**
+ * Unit tests for {@link GenericXmlApplicationContext}.
+ * 
+ * See SPR-7530.
+ *
+ * @author Chris Beams
+ */
+public class GenericXmlApplicationContextTests {
+
+	private static final Class<?> RELATIVE_CLASS = GenericXmlApplicationContextTests.class;
+	private static final String RESOURCE_BASE_PATH = ClassUtils.classPackageAsResourcePath(RELATIVE_CLASS);
+	private static final String RESOURCE_NAME = GenericXmlApplicationContextTests.class.getSimpleName() + "-context.xml";
+	private static final String FQ_RESOURCE_PATH = RESOURCE_BASE_PATH + '/' + RESOURCE_NAME;
+	private static final String TEST_BEAN_NAME = "testBean";
+
+
+	@Test
+	public void classRelativeResourceLoading_ctor() {
+		ApplicationContext ctx = new GenericXmlApplicationContext(RELATIVE_CLASS, RESOURCE_NAME);
+		assertThat(ctx.containsBean(TEST_BEAN_NAME), is(true));
+	}
+
+	@Test
+	public void classRelativeResourceLoading_load() {
+		GenericXmlApplicationContext ctx = new GenericXmlApplicationContext();
+		ctx.load(RELATIVE_CLASS, RESOURCE_NAME);
+		ctx.refresh();
+		assertThat(ctx.containsBean(TEST_BEAN_NAME), is(true));
+	}
+
+	@Test
+	public void fullyQualifiedResourceLoading_ctor() {
+		ApplicationContext ctx = new GenericXmlApplicationContext(FQ_RESOURCE_PATH);
+		assertThat(ctx.containsBean(TEST_BEAN_NAME), is(true));
+	}
+
+	@Test
+	public void fullyQualifiedResourceLoading_load() {
+		GenericXmlApplicationContext ctx = new GenericXmlApplicationContext();
+		ctx.load(FQ_RESOURCE_PATH);
+		ctx.refresh();
+		assertThat(ctx.containsBean(TEST_BEAN_NAME), is(true));
+	}
+}