com.centurylink.mdw.hub.servlet.JsxServlet Maven / Gradle / Ivy

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MDW is a workflow framework specializing in microservice orchestration
There is a newer version: 6.1.39
/*
 * Copyright (C) 2017 CenturyLink, Inc.
 *
 * 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.centurylink.mdw.hub.servlet;

import com.centurylink.mdw.cache.CacheService;
import com.centurylink.mdw.common.service.ServiceException;
import com.centurylink.mdw.config.PropertyManager;
import com.centurylink.mdw.model.asset.AssetInfo;
import com.centurylink.mdw.services.AssetServices;
import com.centurylink.mdw.services.ServiceLocator;
import com.centurylink.mdw.services.cache.CacheRegistration;
import com.centurylink.mdw.util.log.LoggerUtil;
import com.centurylink.mdw.util.log.StandardLogger;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URLEncoder;

@WebServlet(urlPatterns={"*.jsx"})
public class JsxServlet extends HttpServlet {
    private static StandardLogger logger = LoggerUtil.getStandardLogger();
    private static final String NODE_PACKAGE = "com.centurylink.mdw.node";
    private static final String WEBPACK_CACHE_CLASS = NODE_PACKAGE + ".WebpackCache";
    private AssetServices assetServices;
    private String webpackCacheClassName;

    @Override
    public void init(ServletConfig config) throws ServletException {
        super.init(config);
        assetServices = ServiceLocator.getAssetServices();

        webpackCacheClassName = PropertyManager.getProperty("mdw.webpack.cache.class.name");
        if (webpackCacheClassName == null)
            webpackCacheClassName = WEBPACK_CACHE_CLASS;
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
        try {
            if (request.getServletPath().endsWith(".jsx")) {
                String path = request.getServletPath();
                String p = path.substring(1);
                int lastSlash = p.lastIndexOf('/');
                if (lastSlash == -1)
                    throw new ServiceException(ServiceException.NOT_FOUND, "Bad path: " + path);

                String pkgPath = p.substring(0, lastSlash);
                String pkgName = pkgPath.replace('/', '.');
                String assetPath = pkgName + p.substring(lastSlash);
                AssetInfo jsxAsset = assetServices.getAsset(assetPath);
                if (jsxAsset == null) {
                    Exception ex = new ServiceException(ServiceException.NOT_FOUND, "JSX asset not found: " + assetPath);
                    logger.error(ex.getMessage(), ex);
                    String repath = request.getContextPath() + "/404?missingAsset=" + URLEncoder.encode(assetPath, "utf-8");
                    response.getWriter().println("location = '" + repath + "'");
                    return;
                }

                try {
                    CacheService webpackCacheInstance = CacheRegistration.getInstance().getCache(webpackCacheClassName);
                    Method compiledAssetGetter = webpackCacheInstance.getClass().getMethod("getCompiled", AssetInfo.class);
                    File file = (File) compiledAssetGetter.invoke(webpackCacheInstance, jsxAsset);
                    if (shouldCache(file, request.getHeader("If-None-Match"))) {
                        response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
                    }
                    else {
                        response.setHeader("ETag", String.valueOf(file.lastModified()));
                        OutputStream out = response.getOutputStream();
                        try (InputStream in = new FileInputStream(file)) {
                            int read;
                            byte[] bytes = new byte[1024 * 16];
                            while((read = in.read(bytes)) != -1)
                                out.write(bytes, 0, read);
                        }
                    }
                }
                catch (InvocationTargetException ex) {
                    if (ex.getCause() instanceof ServiceException)
                        throw (ServiceException)ex.getCause();
                }
            }
        }
        catch (ServiceException ex) {
            logger.severeException(ex.getMessage(), ex);
            if (ex.getCode() > 0) {
                response.setStatus(ex.getCode());
                response.getWriter().println(ex.getMessage());
            }
        }
        catch (Exception ex) {
            logger.severeException(ex.getMessage(), ex);
        }
    }

    private boolean shouldCache(File file, String ifNoneMatchHeader) {
        if (ifNoneMatchHeader == null)
            return false; // no cache
        try {
            long clientTime = Long.parseLong(ifNoneMatchHeader);
            return clientTime >= file.lastModified();
        }
        catch (NumberFormatException ex) {
            return false;
        }
    }
}