org.squashtest.tm.web.internal.exceptionresolver.HandlerGenericValidation.java Source code

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Here is the source code for org.squashtest.tm.web.internal.exceptionresolver.HandlerGenericValidation.java

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/**
 *     This file is part of the Squashtest platform.
 *     Copyright (C) 2010 - 2016 Henix, henix.fr
 *
 *     See the NOTICE file distributed with this work for additional
 *     information regarding copyright ownership.
 *
 *     This is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU Lesser General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 *
 *     this software is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU Lesser General Public License for more details.
 *
 *     You should have received a copy of the GNU Lesser General Public License
 *     along with this software.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.squashtest.tm.web.internal.exceptionresolver;

import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver;
import org.springframework.web.servlet.view.json.MappingJackson2JsonView;
import org.squashtest.tm.web.internal.http.RequestHeaders;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.validation.ConstraintViolation;
import javax.validation.ConstraintViolationException;
import java.util.*;

@Component
public class HandlerGenericValidation extends AbstractHandlerExceptionResolver {
    private final List<ConstraintViolationHandler> constraintViolationHandlers = new ArrayList<>();

    public HandlerGenericValidation() {
        super();
        constraintViolationHandlers.add(new HasDefaultAsRequiredViolationHandler());
        constraintViolationHandlers.add(new PropertyPathConstraintViolationHandler());
    }

    @Override
    protected ModelAndView doResolveException(HttpServletRequest request, HttpServletResponse response,
            Object handler, Exception ex) {
        if (exceptionIsHandled(ex) && clientAcceptsJson(request)) {
            response.setStatus(HttpServletResponse.SC_PRECONDITION_FAILED);

            ConstraintViolationException cve = (ConstraintViolationException) ex; // NOSONAR Type was checked earlier
            List<FieldValidationErrorModel> errors = buildFieldValidationErrors(cve);

            return new ModelAndView(new MappingJackson2JsonView(), "fieldValidationErrors", errors);
        }

        return null;
    }

    private List<FieldValidationErrorModel> buildFieldValidationErrors(ConstraintViolationException cve) {
        List<FieldValidationErrorModel> ves = new ArrayList<>();

        Set<ConstraintViolation<?>> constraintList = cve.getConstraintViolations();

        for (ConstraintViolation<?> aConstraintList : constraintList) {
            addFieldValidationError(aConstraintList, ves);
        }

        return ves;
    }

    private void addFieldValidationError(ConstraintViolation<?> violation, List<FieldValidationErrorModel> ves) {
        for (ConstraintViolationHandler handler : constraintViolationHandlers) {
            if (handler.handle(violation, ves)) {
                break;
            }
        }
    }

    private boolean exceptionIsHandled(Exception ex) {
        return ex instanceof ConstraintViolationException;
    }

    private boolean clientAcceptsJson(HttpServletRequest request) {
        Enumeration<String> e = request.getHeaders(RequestHeaders.ACCEPT);

        while (e.hasMoreElements()) {
            String header = e.nextElement();
            if (StringUtils.containsIgnoreCase(StringUtils.trimToEmpty(header),
                    MimeType.ANYTHING.requestHeaderValue())
                    || StringUtils.containsIgnoreCase(StringUtils.trimToEmpty(header),
                            MimeType.APPLICATION_JSON.requestHeaderValue())) {
                return true;
            }
        }
        return false;
    }

}