HV-564 Actually not a ConstraintValidatorFactory test, but it shows t…

…hat SoftLimitMRUCache works using BeanMetaDataManager.

We might need to disable this test in case some people report problem.

engine/src/main/java/org/hibernate/validator/internal/metadata/BeanMetaDataManager.java

@@ -106,6 +106,10 @@ public <T> BeanMetaData<T> getBeanMetaData(Class<T> beanClass) {
 		return beanMetaData;
 	}
 
+	public int numberOfCachedBeanMetaDataInstances() {
+		return beanMetaDataCache.softSize();
+	}
+
 	/**
 	 * Creates a {@link org.hibernate.validator.internal.metadata.aggregated.BeanMetaData} containing the meta data from all meta
 	 * data providers for the given type and its hierarchy.

engine/src/test/java/org/hibernate/validator/test/internal/metadata/BeanMetaDataManagerTest.java

@@ -0,0 +1,133 @@
+/*
+* JBoss, Home of Professional Open Source
+* Copyright 2012, Red Hat, Inc. and/or its affiliates, and individual contributors
+* by the @authors tag. See the copyright.txt in the distribution for a
+* full listing of individual contributors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+* http://www.apache.org/licenses/LICENSE-2.0
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+package org.hibernate.validator.test.internal.metadata;
+
+import java.io.DataInputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import javax.validation.constraints.NotNull;
+
+import org.testng.annotations.Test;
+
+import org.hibernate.validator.internal.metadata.BeanMetaDataManager;
+import org.hibernate.validator.internal.metadata.core.ConstraintHelper;
+import org.hibernate.validator.internal.util.logging.Log;
+import org.hibernate.validator.internal.util.logging.LoggerFactory;
+
+import static org.testng.Assert.assertEquals;
+import static org.testng.FileAssert.fail;
+
+
+/**
+ * @author Hardy Ferentschik
+ */
+public class BeanMetaDataManagerTest {
+	private static final Log log = LoggerFactory.make();
+
+	@Test
+	public void testBeanMetaDataCanBeGarbageCollected() throws Exception {
+		BeanMetaDataManager metaDataManager = new BeanMetaDataManager( new ConstraintHelper() );
+
+		for ( int i = 0; i < 200; i++ ) {
+			Class<?> c = new CustomClassLoader( Fubar.class.getName() ).loadClass( Fubar.class.getName() );
+			metaDataManager.getBeanMetaData( c );
+		}
+
+		assertEquals( metaDataManager.numberOfCachedBeanMetaDataInstances(), 200 );
+
+		try {
+			byte[] block = new byte[Integer.MAX_VALUE];
+			fail( "The byte array allocation should have triggered a OutOfMemoryError" );
+		}
+		catch ( OutOfMemoryError ex ) {
+			log.debug( "Successfully forced a OutOfMemoryError" );
+		}
+		// not really reliable. if we get problems with this test we might have to disable it
+		System.gc();
+
+		assertEquals(
+				metaDataManager.numberOfCachedBeanMetaDataInstances(), 128,
+				"Only the hard referenced entries should be left. Soft references should have been garbage collected"
+		);
+	}
+
+	public class Fubar {
+		@NotNull
+		Object o;
+	}
+
+	public class CustomClassLoader extends ClassLoader {
+		private final String className;
+
+		public CustomClassLoader(String className) {
+			super( CustomClassLoader.class.getClassLoader() );
+			this.className = className;
+		}
+
+		public Class loadClass(String className) throws ClassNotFoundException {
+			if ( this.className.equals( className ) ) {
+				return myLoadClass( className, true );
+			}
+			else {
+				return super.loadClass( className );
+			}
+		}
+
+		protected Class<?> myLoadClass(String name, boolean resolve) throws ClassNotFoundException {
+			// make sure there is no parent delegation, instead call custom findClass
+			Class c = myFindClass( name );
+
+			if ( resolve ) {
+				resolveClass( c );
+			}
+			return c;
+		}
+
+		public Class myFindClass(String className) {
+			byte classByte[];
+			Class result;
+
+			try {
+				String classPath = ClassLoader.getSystemResource(
+						className.replace( '.', File.separatorChar )
+								+ ".class"
+				).getFile();
+				classByte = loadClassData( classPath );
+				result = defineClass( className, classByte, 0, classByte.length, null );
+				return result;
+			}
+			catch ( Exception e ) {
+				return null;
+			}
+		}
+
+		private byte[] loadClassData(String className) throws IOException {
+			File f;
+			f = new File( className );
+			int size = (int) f.length();
+			byte buff[] = new byte[size];
+			FileInputStream fis = new FileInputStream( f );
+			DataInputStream dis = new DataInputStream( fis );
+			dis.readFully( buff );
+			dis.close();
+			return buff;
+		}
+	}
+}
+
+