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 * Copyright (c) 2010, 2019 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */
package org.glassfish.jersey.server.model;

import java.util.ArrayList;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;

import org.glassfish.jersey.Severity;
import org.glassfish.jersey.internal.Errors;
import org.glassfish.jersey.message.MessageBodyWorkers;
import org.glassfish.jersey.server.model.internal.ModelErrors;
import org.glassfish.jersey.server.spi.internal.ValueParamProvider;

A resource model validator that checks the given resource model. This base resource model validator class implements the visitor pattern to traverse through all the resource model components to check validity of a resource model. 
 This validator maintains a list of all the issues found in the model. That way all the resource model components can be validated in a single call to the validate(...) method and collect all the validation issues from the model. 
 To check a single resource class, the the Resource builder(...) can be used to create a resource model. validate(ResourceModelComponent) method then populates the issue list, which could be then obtained by the getIssueList(). Unless the list is explicitly cleared, a subsequent calls to the validate method will add new items to the list, so that it can be used to build the issue list for more than one resource. To clear the list, the cleanIssueList() method should be called. 

Author:
Jakub Podlesak, Marek Potociar/**
 * A resource model validator that checks the given resource model.
 *
 * This base resource model validator class implements the visitor pattern to
 * traverse through all the {@link ResourceModelComponent resource model components}
 * to check validity of a resource model.
 * <p />
 * This validator maintains a list of all the {@link ResourceModelIssue issues}
 * found in the model. That way all the resource model components can be validated
 * in a single call to the {@link #validate(ResourceModelComponent) validate(...)}
 * method and collect all the validation issues from the model.
 * <p />
 * To check a single resource class, the the {@link Resource}
 * {@code builder(...)} can be used to create a resource model.
 *
 * {@link ComponentModelValidator#validate(ResourceModelComponent)}
 * method then populates the issue list, which could be then obtained by the
 * {@link ComponentModelValidator#getIssueList()}. Unless the list is explicitly cleared,
 * a subsequent calls to the validate method will add new items to the list,
 * so that it can be used to build the issue list for more than one resource. To clear the
 * list, the {@link ComponentModelValidator#cleanIssueList()} method should be called.
 * <p />
 *
 * @author Jakub Podlesak
 * @author Marek Potociar
 */
public final class ComponentModelValidator {

    private final List<ResourceModelIssue> issueList = new LinkedList<>();

    public ComponentModelValidator(Collection<ValueParamProvider> valueParamProviders, MessageBodyWorkers msgBodyWorkers) {
        validators = new ArrayList<>();
        validators.add(new ResourceValidator());
        validators.add(new RuntimeResourceModelValidator(msgBodyWorkers));
        validators.add(new ResourceMethodValidator(valueParamProviders));
        validators.add(new InvocableValidator());
    }

    private final List<ResourceModelVisitor> validators;

    
Returns a list of issues found after validate(ResourceModelComponent) method has been invoked. 
Returns:
a non-null list of issues./**
     * Returns a list of issues found after
     * {@link #validate(org.glassfish.jersey.server.model.ResourceModelComponent)}
     * method has been invoked.
     *
     * @return a non-null list of issues.
     */
    public List<ResourceModelIssue> getIssueList() {
        return issueList;
    }

    
Convenience method to see if there were fatal issues found.
Returns:
true if there are any fatal issues present in the current issue list./**
     * Convenience method to see if there were fatal issues found.
     *
     * @return {@code true} if there are any fatal issues present in the current
     *         issue list.
     */
    public boolean fatalIssuesFound() {
        for (ResourceModelIssue issue : getIssueList()) {
            if (issue.getSeverity() == Severity.FATAL) {
                return true;
            }
        }
        return false;
    }

    
Removes all issues from the current issue list. The method could be used to re-use the same ComponentModelValidator for another resource model. /**
     * Removes all issues from the current issue list. The method could be used
     * to re-use the same {@link ComponentModelValidator} for another resource model.
     */
    public void cleanIssueList() {
        issueList.clear();
    }

    
The validate method validates a component and adds possible
issues found to it's list. The list of issues could be then retrieved
via getIssueList method.
Params:
component – resource model component./**
     * The validate method validates a component and adds possible
     * issues found to it's list. The list of issues could be then retrieved
     * via getIssueList method.
     *
     * @param component resource model component.
     */
    public void validate(final ResourceModelComponent component) {
        Errors.process(new Runnable() {
            @Override
            public void run() {
                Errors.mark();

                validateWithErrors(component);
                issueList.addAll(ModelErrors.getErrorsAsResourceModelIssues(true));

                Errors.unmark();
            }
        });
    }

    private void validateWithErrors(final ResourceModelComponent component) {
        for (ResourceModelVisitor validator : validators) {
            component.accept(validator);
        }

        final List<? extends ResourceModelComponent> componentList = component.getComponents();
        if (null != componentList) {
            for (ResourceModelComponent subComponent : componentList) {
                validateWithErrors(subComponent);
            }
        }
    }
}