cat.calidos.morfeu.webapp.GenericHttpServlet.java Source code

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Here is the source code for cat.calidos.morfeu.webapp.GenericHttpServlet.java

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/*
 *    Copyright 2018 Daniel Giribet
 *
 *   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 cat.calidos.morfeu.webapp;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Map;
import java.util.Properties;
import java.util.stream.Collectors;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import cat.calidos.morfeu.utils.Config;
import cat.calidos.morfeu.webapp.injection.ControlComponent;
import cat.calidos.morfeu.webapp.injection.DaggerServletConfigComponent;

/**
* @author daniel giribet
*///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
public abstract class GenericHttpServlet extends HttpServlet {

    protected final static Logger log = LoggerFactory.getLogger(GenericHttpServlet.class);

    public static final String METHOD = "__METHOD";
    public static final String POST_VALUE = "__POST";

    protected Properties configuration;
    protected String defaultContentType = "application/json";

    @Override
    public void init(ServletConfig config) throws ServletException {

        super.init(config);

        //TODO: check if there is a more dagger friendly way of doing this
        configuration = DaggerServletConfigComponent.builder().servletConfig(this.getServletConfig()).build()
                .getProperties();

    }

    public abstract ControlComponent getControl(String path, Map<String, String> params);

    public abstract ControlComponent putControl(String path, Map<String, String> params);

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        String path = req.getPathInfo();
        log.trace("GenericMorfeuServlet::doGet {}", path);

        Map<String, String> params = normaliseParams(req.getParameterMap());
        params.put(METHOD, req.getMethod());
        params = processParams(params);

        ControlComponent controlComponent = getControl(path, params);

        handleResponse(resp, controlComponent);

    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        String path = req.getPathInfo();
        log.trace("GenericMorfeuServlet::doPost {}", path);

        Map<String, String> params = normaliseParams(req.getParameterMap());
        params.put(METHOD, req.getMethod());
        String content = IOUtils.toString(req.getInputStream(), Config.DEFAULT_CHARSET);
        params.put(POST_VALUE, content);
        params = processParams(params);

        ControlComponent controlComponent = putControl(path, params);
        handleResponse(resp, controlComponent);

    }

    protected Map<String, String> processParams(Map<String, String> params) {
        return params;
    }

    /** @param req from the servlet
    *    @return normalised path that does not start with '/'
    */
    protected String normalisedPathFrom(HttpServletRequest req) {

        //String path = req.getPathTranslated();
        String path = req.getPathInfo(); // internal model paths are not started with a slash (see tests)
        if (path.startsWith("/")) {
            path = path.substring(1);
        }

        return path;

    }

    protected void writeTo(String content, String contentType, HttpServletResponse resp) throws IOException {

        // to simulate slowness
        //   try {
        //      Thread.sleep(20000);
        //   } catch (InterruptedException e) {
        //      // TODO Auto-generated catch block
        //      e.printStackTrace();
        //   }
        resp.setContentType(contentType);
        PrintWriter out = resp.getWriter();
        out.print(content);
        out.close();

    }

    protected void writeTo(String content, HttpServletResponse resp) throws IOException {
        writeTo(content, defaultContentType, resp);
    }

    protected void handleResponse(HttpServletResponse resp, ControlComponent controlComponent) throws IOException {

        if (controlComponent.matches()) {
            String result = controlComponent.process();
            writeTo(result, controlComponent.contentType(), resp);
        } else {
            log.trace("GenericMorfeuServlet::doPost {} NOT FOUND (not matched)");
            resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
        }
    }

    protected Map<String, String> normaliseParams(Map<String, String[]> parameterMap) {
        return parameterMap.entrySet().stream().collect(Collectors.toMap(e -> e.getKey(), e -> e.getValue()[0]));
    }

}