org.carrot2.util.StringUtils.java Source code

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Here is the source code for org.carrot2.util.StringUtils.java

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/*
 * Carrot2 project.
 *
 * Copyright (C) 2002-2015, Dawid Weiss, Stanisaw Osiski.
 * All rights reserved.
 *
 * Refer to the full license file "carrot2.LICENSE"
 * in the root folder of the repository checkout or at:
 * http://www.carrot2.org/carrot2.LICENSE
 */

package org.carrot2.util;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Iterator;
import java.util.regex.Pattern;

import org.apache.commons.lang.WordUtils;

/**
 * Provides a number of useful method operating on {@link String}s that are not available
 * in {@link org.apache.commons.lang.StringUtils}.
 */
public final class StringUtils {
    private static final Pattern CAMEL_CASE_FRAGMENT = Pattern.compile(
            // a sequence of upper case letters followed by digits
            "([A-Z]{1,}(?=[0-9]+))|" +
            // a sequence of upper case letters followed by an upper letter, followed by lower case or digits
                    "([A-Z]{1,}(?=[A-Z][a-z0-9]+))|" +
                    // upper case letters followed by lower case letters or digits
                    "([A-Z]?[A-Z]+[a-z0-9]+)|" +
                    // sequence of digits
                    "([0-9]+)");
    private static final Pattern HTML_TAG_PATTERN = Pattern.compile("<.+?>", Pattern.CASE_INSENSITIVE);

    private StringUtils() {
    }

    public static <T> String toString(Iterable<T> iterable, String separator) {
        final StringBuilder stringBuilder = new StringBuilder();

        for (final Iterator<T> iterator = iterable.iterator(); iterator.hasNext();) {
            final T object = iterator.next();
            stringBuilder.append(object);
            if (iterator.hasNext()) {
                stringBuilder.append(separator);
            }
        }

        return stringBuilder.toString();
    }

    public static String splitCamelCase(String camelCaseString) {
        return CAMEL_CASE_FRAGMENT.matcher(camelCaseString).replaceAll("$0 ").trim();
    }

    public static String urlEncodeWrapException(String string, String encoding) {
        try {
            return URLEncoder.encode(string, encoding);
        } catch (UnsupportedEncodingException e) {
            throw ExceptionUtils.wrapAsRuntimeException(e);
        }
    }

    public static String removeHtmlTags(String string) {
        return HTML_TAG_PATTERN.matcher(string).replaceAll("");
    }

    public static String identifierToHumanReadable(String string) {
        return WordUtils.capitalizeFully(string.replace('_', ' '));
    }

    /**
     * Join a list of non-null objects with <code>delim</code> and return it
     * as a string.
     */
    public static String join(String delim, Object... objects) {
        final StringBuilder b = new StringBuilder();
        for (Object s : objects) {
            if (s != null) {
                if (b.length() > 0)
                    b.append(delim);
                b.append(s.toString());
            }
        }
        return b.toString();
    }

}