io.curly.artifact.web.remote.PaperclipLinkCatcher.java Source code

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Here is the source code for io.curly.artifact.web.remote.PaperclipLinkCatcher.java

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/*
 *        Copyright 2015 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 io.curly.artifact.web.remote;

import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
import io.curly.artifact.model.Artifact;
import io.curly.commons.web.hateoas.RemoteLinkCatcher;
import io.curly.commons.web.hateoas.ZuulAwareMappingResolver;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.hateoas.Link;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;

import javax.servlet.http.HttpServletRequest;
import java.net.URI;
import java.net.URISyntaxException;

/**
 * @author Joao Pedro Evangelista
 */
@Slf4j
@Component
class PaperclipLinkCatcher implements RemoteLinkCatcher<Artifact> {

    private final LoadBalancerClient loadBalancerClient;

    private final ZuulAwareMappingResolver zuulAwareMappingResolver;

    @Autowired
    PaperclipLinkCatcher(LoadBalancerClient loadBalancerClient, HttpServletRequest request) {
        this.loadBalancerClient = loadBalancerClient;
        this.zuulAwareMappingResolver = new ZuulAwareMappingResolver(request, "/api", "/papers");
    }

    @Override
    @HystrixCommand(fallbackMethod = "noOpLink")
    public Link getLink(Artifact entity) {
        String paperclip = zuulAwareMappingResolver.resolve(loadBalancerClient.choose("paperclip").getUri(),
                entity.getId());
        log.debug("Found remote link {} from client Paperclip", paperclip);
        return new Link(paperclip, "paper");
    }

    public Link noOpLink(Object entity) {
        log.debug("Remote link failed! Returning a null!");
        return null;
    }

    @Override
    public boolean isAvaliable() {
        return true;
    }

    private String reconstructURI(String host, String href) {
        URI original;
        try {
            original = new URI(href);
        } catch (URISyntaxException e) {
            throw new IllegalArgumentException("Cannot create URI from: " + href);
        }
        int port = 80;
        if ("https".equals(original.getScheme())) {
            port = 443;
        }
        if (host.contains(":")) {
            String[] pair = host.split(":");
            host = pair[0];
            port = Integer.valueOf(pair[1]);
        }
        if (host.equals(original.getHost()) && port == original.getPort()) {
            return href;
        }
        String scheme = original.getScheme();
        if (scheme == null) {
            scheme = port == 443 ? "https" : "http";
        }

        StringBuilder sb = new StringBuilder();
        sb.append(scheme).append("://");
        if (StringUtils.hasText(original.getRawUserInfo())) {
            sb.append(original.getRawUserInfo()).append("@");
        }
        sb.append(host);
        if (port >= 0) {
            sb.append(":").append(port);
        }
        sb.append(original.getPath());
        if (StringUtils.hasText(original.getRawQuery())) {
            sb.append("?").append(original.getRawQuery());
        }
        if (StringUtils.hasText(original.getRawFragment())) {
            sb.append("#").append(original.getRawFragment());
        }

        return sb.toString();
    }

}