org.openqa.grid.web.servlet.DisplayHelpHandler.java Source code

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Here is the source code for org.openqa.grid.web.servlet.DisplayHelpHandler.java

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// Licensed to the Software Freedom Conservancy (SFC) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The SFC licenses this file
// to you 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 org.openqa.grid.web.servlet;

import static com.google.common.net.MediaType.CSS_UTF_8;
import static com.google.common.net.MediaType.HTML_UTF_8;
import static com.google.common.net.MediaType.ICO;
import static com.google.common.net.MediaType.JAVASCRIPT_UTF_8;
import static com.google.common.net.MediaType.JPEG;
import static com.google.common.net.MediaType.PNG;
import static java.nio.charset.StandardCharsets.UTF_8;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableMap;
import com.google.common.io.ByteStreams;
import com.google.common.net.MediaType;

import org.openqa.grid.common.GridRole;
import org.openqa.selenium.BuildInfo;
import org.openqa.selenium.grid.web.CommandHandler;
import org.openqa.selenium.json.Json;
import org.openqa.selenium.json.JsonOutput;
import org.openqa.selenium.remote.http.HttpRequest;
import org.openqa.selenium.remote.http.HttpResponse;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Map;
import java.util.Objects;
import java.util.stream.Collectors;

import javax.servlet.http.HttpServletResponse;

/**
 * Displays a somewhat useful help signpost page.
 */
public class DisplayHelpHandler implements CommandHandler {

    private static Map<String, MediaType> TYPES = ImmutableMap.of(".js", JAVASCRIPT_UTF_8, ".css", CSS_UTF_8,
            ".png", PNG, ".jpg", JPEG, ".ico", ICO);

    private static final String HELPER_SERVLET_TEMPLATE = "displayhelpservlet.html";
    private static final String HELPER_SERVLET_ASSET_PATH_PREFIX = "/assets/";
    private static final String HELPER_SERVLET_RESOURCE_PATH = "org/openqa/grid/images/";
    private static final String HELPER_SERVLET_TEMPLATE_CONFIG_JSON_VAR = "${servletConfigJson}";

    private final Json json;
    private final GridRole role;
    private final DisplayHelpServletConfig servletConfig;

    public DisplayHelpHandler(Json json, GridRole role, String consolePath) {
        this.json = Objects.requireNonNull(json);
        this.role = Objects.requireNonNull(role);

        this.servletConfig = new DisplayHelpServletConfig(new BuildInfo().getReleaseLabel(), getHelperType(),
                consolePath);
    }

    @Override
    public void execute(HttpRequest req, HttpResponse resp) throws IOException {
        String resource = req.getUri();
        if (resource.contains(HELPER_SERVLET_ASSET_PATH_PREFIX)
                && !resource.replace(HELPER_SERVLET_ASSET_PATH_PREFIX, "").contains("/")
                && !resource.replace(HELPER_SERVLET_ASSET_PATH_PREFIX, "").equals("")) {
            // request is for an asset of the help page
            resource = resource.replace(HELPER_SERVLET_ASSET_PATH_PREFIX, "");
            int index = resource.lastIndexOf('.');
            MediaType type = HTML_UTF_8;
            if (index != -1) {
                String extension = resource.substring(index);
                type = TYPES.getOrDefault(extension, HTML_UTF_8);
            }

            resp.setHeader("Content-Type", type.toString());

            try (InputStream in = getResourceInputStream(resource)) {
                if (in == null) {
                    resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
                    return;
                } else {
                    resp.setStatus(HttpServletResponse.SC_OK);
                    resp.setContent(ByteStreams.toByteArray(in));
                    return;
                }
            }
        } else {
            // request is for an unknown entity. show the help page
            try (InputStream in = getResourceInputStream(HELPER_SERVLET_TEMPLATE)) {
                if (in == null) {
                    resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
                } else {
                    StringBuilder jsonBuilder = new StringBuilder();
                    try (JsonOutput out = json.newOutput(jsonBuilder)) {
                        out.setPrettyPrint(false).write(servletConfig);
                    }

                    final String json = jsonBuilder.toString();

                    final String htmlTemplate;
                    try (BufferedReader reader = new BufferedReader(new InputStreamReader(in, UTF_8))) {
                        htmlTemplate = reader.lines().collect(Collectors.joining("\n"));
                    }
                    final String updatedTemplate = htmlTemplate.replace(HELPER_SERVLET_TEMPLATE_CONFIG_JSON_VAR,
                            json);
                    if (resource.equals("/")) {
                        resp.setStatus(HttpServletResponse.SC_OK);
                    } else {
                        resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
                    }

                    resp.setHeader("Content-Type", HTML_UTF_8.toString());
                    resp.setContent(updatedTemplate.getBytes(UTF_8));
                }
            }
        }
    }

    @VisibleForTesting
    String getHelperType() {
        switch (role) {
        case HUB: {
            return "Grid Hub";
        }
        case NODE: {
            return "Grid Node";
        }
        default: {
            return "Standalone";
        }
        }
    }

    private InputStream getResourceInputStream(String resource) {
        InputStream in = Thread.currentThread().getContextClassLoader()
                .getResourceAsStream(HELPER_SERVLET_RESOURCE_PATH + resource);
        if (in == null) {
            return null;
        }
        return in;
    }

    private final class DisplayHelpServletConfig {

        private final String version;
        private final String type;
        private final String consoleLink;

        public DisplayHelpServletConfig(String version, String type, String consoleLink) {
            this.version = Objects.requireNonNull(version);
            this.type = Objects.requireNonNull(type);
            this.consoleLink = Objects.requireNonNull(consoleLink);
        }

        public String getVersion() {
            return version;
        }

        public String getType() {
            return type;
        }

        public String getConsoleLink() {
            return consoleLink;
        }
    }
}