Java tutorial
/* * Copyright 2016 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 * * 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 capital.scalable.restdocs.constraints; import java.lang.annotation.Annotation; import java.lang.reflect.Method; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import org.springframework.core.MethodParameter; import org.springframework.restdocs.constraints.Constraint; import org.springframework.restdocs.constraints.ValidatorConstraintResolver; public class MethodParameterValidatorConstraintResolver extends ValidatorConstraintResolver implements MethodParameterConstraintResolver { @Override public List<Constraint> resolveForParameter(MethodParameter param) { List<Constraint> constraints = new ArrayList<>(); for (Annotation annot : param.getParameterAnnotations()) { Class<? extends Annotation> type = annot.annotationType(); if (type.getAnnotation(javax.validation.Constraint.class) != null) { Constraint constraint = createConstraint(annot, type); constraints.add(constraint); } } return constraints; } private Constraint createConstraint(Annotation annot, Class<? extends Annotation> type) { Map<String, Object> configuration = new HashMap(); for (Method method : type.getDeclaredMethods()) { String methodName = method.getName(); Object value = getAnnotValue(annot, method); configuration.put(methodName, value); } return new Constraint(type.getName(), configuration); } private Object getAnnotValue(Annotation annot, Method method) { try { return method.invoke(annot); } catch (Exception e) { // do not fail on error, just return null as the value of the field return null; } } }