org.sventon.util.WebUtils.java Source code

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Here is the source code for org.sventon.util.WebUtils.java

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/*
 * ====================================================================
 * Copyright (c) 2005-2012 sventon project. All rights reserved.
 *
 * This software is licensed as described in the file LICENSE, which
 * you should have received as part of this distribution. The terms
 * are also available at http://www.sventon.org.
 * If newer versions of this license are posted there, you may use a
 * newer version instead, at your option.
 * ====================================================================
 */
package org.sventon.util;

import org.apache.commons.lang.StringUtils;

import javax.servlet.http.HttpServletRequest;
import java.util.regex.Pattern;

/**
 * Web related utility methods.
 *
 * @author jesper@sventon.org
 */
public final class WebUtils {

    public static final String APPLICATION_OCTET_STREAM = "application/octet-stream";
    public static final String CONTENT_TYPE_TEXT_PLAIN = "text/plain; charset=\"UTF-8\"";

    /**
     * Content disposition Response header.
     */
    public static final String CONTENT_DISPOSITION_HEADER = "Content-disposition";

    public static final String NL = System.getProperty("line.separator");
    public static final String NBSP = " ";
    public static final Pattern NL_REGEXP = Pattern.compile("(\r\n|\r|\n|\n\r)");

    /**
     * Private constructor to prevent instantiation.
     */
    private WebUtils() {
    }

    /**
     * Replaces any new line characters with a HTML BR.
     *
     * @param string String to replace
     * @return Result, or <tt>null</tt> if given input was <tt>null</tt>.
     */
    public static String nl2br(final String string) {
        if (StringUtils.isEmpty(string)) {
            return string;
        }
        return NL_REGEXP.matcher(string).replaceAll("<br>");
    }

    /**
     * Replaces leading spaces with the HTML entity <code>&nbsp;</code>.
     *
     * @param string Input string. Can be one or more lines.
     * @return Replaced output string.
     */
    public static String replaceLeadingSpaces(final String string) {
        if (StringUtils.isEmpty(string)) {
            return string;
        }

        final StringBuilder sb = new StringBuilder();
        final String[] lines = NL_REGEXP.split(string);

        for (final String line : lines) {
            if (!StringUtils.isWhitespace(line)) {
                String result = org.springframework.util.StringUtils.trimLeadingWhitespace(line);

                int removedSpacesCount = line.length() - result.length();
                for (int i = 0; i < removedSpacesCount; i++) {
                    result = NBSP + result;
                }
                sb.append(result);
            } else {
                sb.append(line);
            }
            // Make sure to only append NEWLINE when multiple lines.
            if (lines.length > 1) {
                sb.append(NL);
            }
        }
        return sb.toString();
    }

    /**
     * Extracts the full request URL, including scheme, server name,
     * server port (if not 80) and context path.
     *
     * @param request The request.
     * @return The full URL, ending with a forward slash (/).
     */
    public static String extractBaseURLFromRequest(final HttpServletRequest request) {
        final StringBuilder sb = new StringBuilder();
        sb.append(request.getScheme());
        sb.append("://");
        sb.append(request.getServerName());
        if (request.getServerPort() != 80) {
            sb.append(":");
            sb.append(request.getServerPort());
        }
        sb.append(request.getContextPath());
        sb.append("/");
        return sb.toString();
    }

}