io.milton.http.annotated.CTagAnnotationHandler.java Source code

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Here is the source code for io.milton.http.annotated.CTagAnnotationHandler.java

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/*
 * Copyright 2013 McEvoy Software Ltd.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * This program 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 General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package io.milton.http.annotated;

import io.milton.annotations.CTag;
import io.milton.http.exceptions.BadRequestException;
import io.milton.http.exceptions.NotAuthorizedException;
import io.milton.resource.CollectionResource;
import io.milton.resource.Resource;
import java.util.Date;
import org.apache.commons.beanutils.PropertyUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 *
 * @author brad
 */
public class CTagAnnotationHandler extends AbstractAnnotationHandler {

    private static final Logger log = LoggerFactory.getLogger(CTagAnnotationHandler.class);

    public static String deriveCtag(CollectionResource col) throws NotAuthorizedException, BadRequestException {
        Date latest = col.getModifiedDate();
        for (Resource r : col.getChildren()) {
            Date d = r.getModifiedDate();
            if (d != null) {
                if (latest == null || d.after(latest)) {
                    latest = d;
                }
            }
        }

        String ctag = null;
        if (latest != null) {
            ctag = "T" + latest.getTime();
        }
        return ctag;
    }

    private final String[] CTAG_PROP_NAMES = { "ctag" };

    public CTagAnnotationHandler(final AnnotationResourceFactory outer) {
        super(outer, CTag.class);
    }

    public String execute(AnnoCollectionResource col) {
        Object source = col.getSource();
        try {
            Object rawId = null;
            ControllerMethod cm = getBestMethod(source.getClass());
            if (cm == null) {
                // look for an annotation on the source itself
                java.lang.reflect.Method m = annoResourceFactory.findMethodForAnno(source.getClass(), annoClass);
                if (m != null) {
                    rawId = m.invoke(source);
                    if (log.isDebugEnabled()) {
                        log.debug("Got ctag from source object. ctag=" + rawId);
                    }

                } else {
                    for (String nameProp : CTAG_PROP_NAMES) {
                        if (PropertyUtils.isReadable(source, nameProp)) {
                            Object oPropVal = PropertyUtils.getProperty(source, nameProp);
                            rawId = oPropVal;
                            if (log.isDebugEnabled()) {
                                log.debug("Got ctag from bean property:" + nameProp + "  ctag=" + rawId);
                            }

                            break;
                        }
                    }
                    if (rawId == null) {
                        // last ditch effort, use latest mod date on the collection or any member
                        rawId = deriveCtag(col);
                        if (log.isInfoEnabled()) {
                            log.debug(
                                    "Derived ctag from directory members. This is not recommended, you should implement an @CTag method. Ctag="
                                            + rawId);
                        }
                    }

                }
            } else {
                rawId = cm.method.invoke(cm.controller, source);
                if (log.isDebugEnabled()) {
                    log.debug("Got ctag from annotated method. ctag=" + rawId);
                }
            }
            if (rawId != null) {
                String s = rawId.toString();
                if (s.length() == 0) {
                    log.warn("CTAG value is blank");
                }
                return s;
            } else {
                log.warn("CTAG value is null");
                return null;
            }
        } catch (Exception e) {
            throw new RuntimeException("Exception executing " + getClass() + " - " + source.getClass(), e);
        }
    }
}