Java tutorial
package com.devicehive.util; /* * #%L * DeviceHive Java Server Common business logic * %% * Copyright (C) 2016 DataArt * %% * 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. * #L% */ import com.devicehive.exceptions.HiveException; import org.apache.commons.lang3.StringUtils; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import javax.validation.ConstraintViolation; import javax.validation.Validator; import java.util.HashSet; import java.util.Set; import static javax.ws.rs.core.Response.Status.BAD_REQUEST; @Component public class HiveValidator { @Autowired private Validator validator; /** * Validates object representation. * * @param object Object that should be validated * @throws HiveException if there is any constraint violations. */ public <T> void validate(T object) { Set<ConstraintViolation<?>> violations = new HashSet<>(validator.validate(object)); if (!violations.isEmpty()) { String response = buildMessage(violations); throw new HiveException(response, BAD_REQUEST.getStatusCode()); } } public String buildMessage(Set<ConstraintViolation<?>> violations) { StringBuilder builder = new StringBuilder("Error! Validation failed: \n"); for (ConstraintViolation<?> cv : violations) { builder.append(String.format("On property %s (value: %s): %s ; %n", cv.getPropertyPath(), cv.getInvalidValue(), cv.getMessage())); } return StringUtils.removeEnd(builder.toString(), " \n"); } }