com.google.publicalerts.cap.validator.ValidatorUtil.java Source code

Introduction

Here is the source code for com.google.publicalerts.cap.validator.ValidatorUtil.java

Source

/*
 * Copyright (C) 2011 Google 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.google.publicalerts.cap.validator;

import java.io.BufferedReader;
import java.io.UnsupportedEncodingException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URLEncoder;
import java.nio.charset.Charset;
import java.util.List;
import java.util.Set;

import javax.servlet.http.HttpServletResponse;

import com.google.common.base.Splitter;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;

import com.google.publicalerts.cap.CapUtil;
import com.google.publicalerts.cap.profile.CapProfile;
import com.google.publicalerts.cap.profile.CapProfiles;

/**
 * Validator utils, common to multiple servlets.
 *
 * @author shakusa@google.com (Steve Hakusa)
 */
public class ValidatorUtil {

    public static final String GOOGLE_ANALYTICS_ID = "google_analytics_id";
    public static final String ALERT_HUB_SECRET = "alert_hub_secret";
    public static final String ALERT_HUB_URL = "alert_hub_url";

    private static final Charset UTF8 = Charset.forName("UTF-8");

    /**
     * Returns the given set of selected cap profiles in a format
     * suitable for displaying in the validator JSPs.
     *
     * @param selected the selected CAP profiles, may be empty
     * @return the JSP-formatted profiles
     */
    public static List<String[]> getProfilesJsp(Set<CapProfile> selected) {
        selected = selected == null ? ImmutableSet.<CapProfile>of() : selected;
        List<String[]> ret = Lists.newArrayList();
        for (CapProfile profile : CapProfiles.getProfiles()) {
            String checked = (selected.contains(profile) ? "checked" : "");
            ret.add(new String[] { profile.getCode(), checked, profile.getDocumentationUrl(), profile.getName() });
        }
        return ret;
    }

    public static Set<CapProfile> parseProfiles(String profileStr) {
        if (CapUtil.isEmptyOrWhitespace(profileStr)) {
            return ImmutableSet.of();
        }

        Splitter splitter = Splitter.on(",").trimResults().omitEmptyStrings();
        List<String> profileList = Lists.newArrayList(splitter.split(profileStr));
        Set<CapProfile> profiles = Sets.newHashSet();
        for (CapProfile profile : CapProfiles.getProfiles()) {
            for (String p : profileList) {
                if (profile.getCode().equals(p)) {
                    profiles.add(profile);
                }
            }
        }
        return profiles;
    }

    /**
     * Adds headers to the given response to mark it as not cacheable.
     *
     * @param resp the response to add headers to.
     */
    public static void addNoCachableHeaders(HttpServletResponse resp) {
        resp.setHeader("Cache-Control", "no-cache, no-store, max-age=0, must-revalidate");
        resp.setHeader("Pragma", "no-cache");
        resp.setHeader("Expires", "Fri, 01 Jan 1990 00:00:00 GMT");
        resp.setDateHeader("Date", System.currentTimeMillis());
    }

    /**
     * Creates a PSHB callback url given the request url, topic url, and email.
     *
     * @param reqUrl the URL of the request to the validator
     * @param topic the URL of the feed on whose behalf we are subscribing the
     *   validator
     * @param email the email address to send errors
     */
    public static String toCallbackUrl(String reqUrl, String topic, String email) {
        try {
            return reqUrl + "?topic=" + URLEncoder.encode(topic, "UTF-8") + "&email="
                    + URLEncoder.encode(email, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Reads the given stream to a string and closes it.
     *
     * @param stream the stream to read
     * @throws IOException on error reading from the stream
     */
    public static String readFully(InputStream stream) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(stream, UTF8));
        StringBuilder sb = new StringBuilder();
        String line;
        while ((line = br.readLine()) != null) {
            sb.append(line).append('\n');
        }
        if (sb.length() > 0) {
            sb.setLength(sb.length() - 1);
        }
        stream.close();
        return sb.toString();
    }

    private ValidatorUtil() {
    }
}