/*
* JBoss, Home of Professional Open Source
* Copyright 2013, 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.parameternameprovider;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.List;
import javax.validation.ParameterNameProvider;
import com.thoughtworks.paranamer.AdaptiveParanamer;
import com.thoughtworks.paranamer.CachingParanamer;
import com.thoughtworks.paranamer.Paranamer;
import org.hibernate.validator.internal.engine.DefaultParameterNameProvider;
/**
* A {@link ParameterNameProvider} implementation backed by the <a href="http://paranamer.codehaus.org/">ParaNamer</a>
* library.
* <p>
* The {@link Paranamer} implementation to use can be passed when creating a {@code ParanamerParameterNameProvider}. By
* default a {@link AdaptiveParanamer} will be used which is wrapped into a {@link CachingParanamer}. If no parameter
* names can be obtained from the configured {@code Paranamer}, the default parameter name provider will be used as
* fall back.
* <p>
* The ParaNamer library must be present on the classpath when using this parameter name provider.
*
* @author Gunnar Morling
* @see <a href="http://paranamer.codehaus.org/">ParaNamer web site</a>
*/
public class ParanamerParameterNameProvider implements ParameterNameProvider {
private final ParameterNameProvider fallBackProvider;
private final Paranamer paranamer;
public ParanamerParameterNameProvider() {
this( null );
}
public ParanamerParameterNameProvider(Paranamer paranamer) {
this.paranamer = paranamer != null ? paranamer : new CachingParanamer( new AdaptiveParanamer() );
fallBackProvider = new DefaultParameterNameProvider();
}
@Override
public List<String> getParameterNames(Constructor<?> constructor) {
String[] parameterNames;
//there are no guarantees regarding thread-safety
synchronized ( paranamer ) {
parameterNames = paranamer.lookupParameterNames( constructor, false );
}
//either null or an empty array is returned if no names could be retrieved
if ( parameterNames != null && parameterNames.length == constructor.getParameterTypes().length ) {
return Arrays.asList( parameterNames );
}
return fallBackProvider.getParameterNames( constructor );
}
@Override
public List<String> getParameterNames(Method method) {
String[] parameterNames;
synchronized ( paranamer ) {
parameterNames = paranamer.lookupParameterNames( method, false );
}
if ( parameterNames != null && parameterNames.length == method.getParameterTypes().length ) {
return Arrays.asList( parameterNames );
}
return fallBackProvider.getParameterNames( method );
}
}