com.expedia.seiso.web.hateoas.link.RepoSearchLinks.java Source code

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Here is the source code for com.expedia.seiso.web.hateoas.link.RepoSearchLinks.java

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/* 
 * Copyright 2013-2015 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 com.expedia.seiso.web.hateoas.link;

import java.net.URI;
import java.util.ArrayList;
import java.util.Collections;

import lombok.NonNull;
import lombok.RequiredArgsConstructor;
import lombok.val;

import org.springframework.data.domain.Page;
import org.springframework.stereotype.Component;
import org.springframework.util.MultiValueMap;
import org.springframework.web.util.UriComponentsBuilder;

import com.expedia.seiso.domain.meta.ItemMetaLookup;
import com.expedia.seiso.web.hateoas.Link;

/**
 * @author Willie Wheeler
 */
@Component
@RequiredArgsConstructor
public class RepoSearchLinks {
    private static final String BASE_SEARCH_PATH = "search";

    /** Includes version prefix; e.g., /v1, /v2 */
    @NonNull
    private URI versionUri;

    @NonNull
    private ItemPaths itemPaths;
    @NonNull
    private ItemMetaLookup itemMetaLookup;

    public Link repoSearchListLink(@NonNull String rel, @NonNull Class<?> itemClass) {
        // @formatter:off
        val href = UriComponentsBuilder.fromUri(versionUri).pathSegment(repoPath(itemClass), BASE_SEARCH_PATH)
                .build().toString();
        // @formatter:on
        return new Link(rel, href);
    }

    public Link toRepoSearchLinkTemplate(@NonNull String rel, @NonNull Class itemClass, @NonNull String path,
            @NonNull MultiValueMap<String, String> params) {

        val hrefBuilder = new StringBuilder();

        // @formatter:off
        hrefBuilder.append(versionUri).append("/").append(repoPath(itemClass)).append("/").append(BASE_SEARCH_PATH)
                .append("/").append(path);
        // @formatter:off

        val queryString = toQueryString(params);
        if (!queryString.isEmpty()) {
            hrefBuilder.append("?");
            hrefBuilder.append(queryString);
        }

        val link = new Link(rel, hrefBuilder.toString());
        link.setTemplated(true);
        return link;
    }

    public PaginationLinkBuilder toPaginationLinkBuilder(@NonNull Page page, @NonNull Class itemClass,
            @NonNull String path, @NonNull MultiValueMap<String, String> params) {

        // @formatter:off
        val uriComponents = UriComponentsBuilder.fromUri(versionUri)
                .pathSegment(repoPath(itemClass), BASE_SEARCH_PATH, path).build();
        // @formatter:on

        return new PaginationLinkBuilder(page, uriComponents, params);
    }

    private String repoPath(Class<?> itemClass) {
        return itemMetaLookup.getItemMeta(itemClass).getRepoKey();
    }

    private String toQueryString(MultiValueMap<String, String> params) {
        val paramNames = new ArrayList<String>(params.keySet());
        Collections.sort(paramNames);

        val builder = new StringBuilder();
        boolean first = true;
        for (val paramName : paramNames) {
            if (!first) {
                builder.append("&");
            }
            builder.append(paramName);
            builder.append("=");

            // FIXME The responsibility for formatting template variables belongs here, not with the clients. [WLW]
            builder.append(params.getFirst(paramName));

            first = false;
        }

        return builder.toString();
    }
}