com.microservice.training.hal.HalBrowser.java Source code

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Here is the source code for com.microservice.training.hal.HalBrowser.java

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/*
 * Copyright 2015-2016 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.microservice.training.hal;

import org.springframework.http.MediaType;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.View;
import org.springframework.web.servlet.support.ServletUriComponentsBuilder;
import org.springframework.web.servlet.view.RedirectView;
import org.springframework.web.util.UriComponents;

import javax.servlet.http.HttpServletRequest;

/**
 * Controller with a few convenience redirects to expose the HAL browser shipped as static content.
 * 
 * @author Oliver Gierke
 * @soundtrack Miles Davis - So what (Kind of blue)
 */
@Controller
public class HalBrowser {

    private static String BROWSER = "/browser";
    private static String INDEX = "/index.html";

    /**
     * Redirects requests to the API root asking for HTML to the HAL browser.
     * 
     * @return
     */
    @RequestMapping(value = { "/", "" }, method = RequestMethod.GET, produces = MediaType.TEXT_HTML_VALUE)
    public View index(HttpServletRequest request) {
        return getRedirectView(request, false);
    }

    /**
     * Redirects to the actual {@code index.html}.
     * 
     * @return
     */
    @RequestMapping(value = "/browser", method = RequestMethod.GET)
    public View browser(HttpServletRequest request) {
        return getRedirectView(request, request.getRequestURI().endsWith("/browser"));
    }

    /**
     * Returns the View to redirect to to access the HAL browser.
     * 
     * @param request must not be {@literal null}.
     * @param browserRelative
     * @return
     */
    private View getRedirectView(HttpServletRequest request, boolean browserRelative) {

        ServletUriComponentsBuilder builder = ServletUriComponentsBuilder.fromRequest(request);

        UriComponents components = builder.build();
        String path = components.getPath() == null ? "" : components.getPath();

        if (!browserRelative) {
            builder.path(BROWSER);
        }

        builder.path(INDEX);
        builder.fragment(browserRelative ? path.substring(0, path.lastIndexOf("/browser")) : path);

        return new RedirectView(builder.build().toUriString());
    }
}