org.springframework.core.PrioritizedParameterNameDiscoverer Maven / Gradle / Ivy
/*
* Copyright 2002-2017 the original author or authors.
*
* 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
*
* https://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.springframework.core;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.LinkedList;
import java.util.List;
/**
* {@link ParameterNameDiscoverer} implementation that tries several discoverer
* delegates in succession. Those added first in the {@code addDiscoverer} method
* have highest priority. If one returns {@code null}, the next will be tried.
*
* The default behavior is to return {@code null} if no discoverer matches.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @since 2.0
*/
public class PrioritizedParameterNameDiscoverer implements ParameterNameDiscoverer {
private final List parameterNameDiscoverers =
new LinkedList();
/**
* Add a further {@link ParameterNameDiscoverer} delegate to the list of
* discoverers that this {@code PrioritizedParameterNameDiscoverer} checks.
*/
public void addDiscoverer(ParameterNameDiscoverer pnd) {
this.parameterNameDiscoverers.add(pnd);
}
@Override
public String[] getParameterNames(Method method) {
for (ParameterNameDiscoverer pnd : this.parameterNameDiscoverers) {
String[] result = pnd.getParameterNames(method);
if (result != null) {
return result;
}
}
return null;
}
@Override
public String[] getParameterNames(Constructor ctor) {
for (ParameterNameDiscoverer pnd : this.parameterNameDiscoverers) {
String[] result = pnd.getParameterNames(ctor);
if (result != null) {
return result;
}
}
return null;
}
}