com.threewks.thundr.route.Route.java Source code

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Here is the source code for com.threewks.thundr.route.Route.java

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/*
 * This file is a component of thundr, a software library from 3wks.
 * Read more: http://3wks.github.io/thundr/
 * Copyright (C) 2014 3wks, <thundr@3wks.com.au>
 *
 * 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.threewks.thundr.route;

import static com.atomicleopard.expressive.Expressive.list;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.lang3.StringUtils;

import com.atomicleopard.expressive.EList;
import com.threewks.thundr.http.URLEncoder;

public class Route {
    public static final String PathParameterToken = "\\{(.*?)\\}";
    public static final Pattern PathParameterPattern = Pattern.compile(PathParameterToken);
    // from -> http://www.ietf.org/rfc/rfc1738.txt: "Thus, only alphanumerics, the special characters "$-_.+!*'()," ... may be used unencoded within a URL."
    public static final String AcceptablePathCharacters = "\\w%:@&=+$,!~*'()\\.\\-";
    public static final String AcceptableMultiPathCharacters = AcceptablePathCharacters + "/";

    // TODO - Binding path segment request parameters
    // The spec allows for request parameters to be encoded in the format /url/url2/url3;key=value;key2=value2
    // This seems to only happen in jetty and tomcat (some versions) when redirects are invoked, particularly if the server
    // hasn't confirmed that the client supports cookies. i.e. redirect -> /go/here;jsessionid=12345678
    // This is a hack implementation which satisfies most current web development needs, further reading on a fuller implementation here:
    // http://www.skorks.com/2010/05/what-every-developer-should-know-about-urls/
    public static final String SemiColonDelimitedRequestParameters = "(?:;.*?)*";

    private String name;
    private String route;
    private Pattern routeMatchRegex;
    private HttpMethod method;
    private EList<String> pathParameters;

    public Route(HttpMethod method, String route, String nameOrNull) {
        super();
        this.name = nameOrNull;
        this.route = route;
        this.method = method;
        this.pathParameters = extractPathParametersFromRoute(route);
        this.routeMatchRegex = Pattern.compile(convertPathStringToRegex(route));
    }

    public String getName() {
        return name;
    }

    public String getRoute() {
        return route;
    }

    public String getRouteMatchRegex() {
        return routeMatchRegex.pattern();
    }

    public HttpMethod getMethod() {
        return method;
    }

    public boolean matches(String routePath) {
        return routeMatchRegex.matcher(routePath).matches();
    }

    public String getReverseRoute(Map<String, Object> pathVars) {
        List<String> missing = list(pathParameters).removeItems(pathVars.keySet());
        if (!missing.isEmpty()) {
            throw new ReverseRouteException(
                    "Cannot generate a reverse route for %s - no value(s) supplied for the path variables %s",
                    route, StringUtils.join(missing, ", "));
        }
        if (pathVars.values().contains(null)) {
            throw new ReverseRouteException(
                    "Cannot generate a reverse route for %s - one or more parameters were null", route);
        }
        String reverse = route;
        for (Map.Entry<String, Object> entry : pathVars.entrySet()) {
            reverse = reverse.replace("{" + entry.getKey() + "}",
                    URLEncoder.encodePathComponent(entry.getValue().toString()));
        }
        return reverse;
    }

    public Map<String, String> getPathVars(String routePath) {
        Matcher matcher = routeMatchRegex.matcher(routePath);
        matcher.find();
        int count = matcher.groupCount();
        Map<String, String> results = new HashMap<String, String>();
        for (int i = 1; i <= count; i++) {
            String name = pathParameters.get(i - 1);

            results.put(name, URLEncoder.decodePathComponent(matcher.group(i)));
        }
        return results;
    }

    @Override
    public String toString() {
        String nameString = StringUtils.isBlank(name) ? "" : " (" + name + ")";
        return String.format("%-8s%-50s%16s", method, route, nameString);
    }

    static String convertPathStringToRegex(String route) {
        String wildCardPlaceholder = "____placeholder____";
        route = route.replaceAll("\\*\\*", wildCardPlaceholder);
        route = route.replaceAll("\\*", Matcher.quoteReplacement("[" + AcceptablePathCharacters + "]*?"));
        route = PathParameterPattern.matcher(route)
                .replaceAll(Matcher.quoteReplacement("([" + AcceptablePathCharacters + "]+)"));
        route = route.replaceAll(wildCardPlaceholder,
                Matcher.quoteReplacement("[" + AcceptableMultiPathCharacters + "]*?"));
        return route + SemiColonDelimitedRequestParameters;
    }

    static EList<String> extractPathParametersFromRoute(String route) {
        Matcher matcher = PathParameterPattern.matcher(route);
        EList<String> results = list();
        while (matcher.find()) {
            String parameter = matcher.group(1);
            results.add(parameter);
        }
        return results;
    }
}