org.attribyte.api.pubsub.impl.server.util.ServerUtil.java Source code

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Here is the source code for org.attribyte.api.pubsub.impl.server.util.ServerUtil.java

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/*
 * Copyright 2014 Attribyte, LLC
 *
 * 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 org.attribyte.api.pubsub.impl.server.util;

import com.google.common.base.Splitter;
import com.google.common.base.Strings;
import com.google.common.collect.Lists;

import javax.servlet.http.HttpServletRequest;
import java.util.Collections;
import java.util.List;

public class ServerUtil {

    /**
     * The system property that points to the installation directory.
     */
    public static final String PUBSUB_INSTALL_DIR_SYSPROP = "pubsub.install.dir";

    /**
     * Gets the system install directory (always ends with '/').
     * @return The directory.
     */
    public static String systemInstallDir() {
        String systemInstallDir = System.getProperty(PUBSUB_INSTALL_DIR_SYSPROP, "").trim();
        if (systemInstallDir.length() > 0 && !systemInstallDir.endsWith("/")) {
            systemInstallDir = systemInstallDir + "/";
        }
        return systemInstallDir;
    }

    /**
     * Splits the path into a list of components.
     * @param request The request.
     * @return The path.
     */
    public static List<String> splitPath(final HttpServletRequest request) {
        String pathInfo = request.getPathInfo();
        if (pathInfo == null || pathInfo.length() == 0 || pathInfo.equals("/")) {
            return Collections.emptyList();
        } else {
            return Lists.newArrayList(pathSplitter.split(pathInfo));
        }
    }

    private static final Splitter pathSplitter = Splitter.on('/').omitEmptyStrings().trimResults();

    /**
     * Escape a string for HTML display.
     * @param str The string.
     * @return The escaped string.
     */
    public static final String htmlEscape(String str) {

        if (str == null) {
            return null;
        }

        StringBuilder buf = new StringBuilder();
        char[] chars = str.toCharArray();
        for (char curr : chars) {
            switch (curr) {
            case '&':
                buf.append("&amp;");
                break;
            case '<':
                buf.append("&lt;");
                break;
            case '>':
                buf.append("&gt;");
                break;
            case '\"':
                buf.append("&quot;");
                break;
            default:
                buf.append(curr);
            }
        }

        return buf.toString();
    }

    /**
     * Gets an integer value from a servlet request.
     * @param request The request.
     * @param name The parameter name.
     * @param defaultValue The default value.
     * @return The request or default value.
     */
    public static int getParameter(final HttpServletRequest request, final String name, final int defaultValue) {
        String intVal = Strings.nullToEmpty(request.getParameter(name)).trim();
        try {
            return intVal.isEmpty() ? defaultValue : Integer.parseInt(intVal);
        } catch (NumberFormatException nfe) {
            return defaultValue;
        }
    }

    /**
     * The content type header for JSON ('application/json').
     */
    public static final String JSON_CONTENT_TYPE = "application/json";
}