package com.nationalelectric.greenH5.identityAuth.util.devon;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.StringTokenizer;

/**
 *
 * @author <a href="mailto:93785732@qq.com">ZhengDaHong@fzfx</a>
 * @since 2017/4/14 11:40
 */
public abstract class StringUtils {

	public static final char UPPER_CASE_A = 'A';
	public static final char UPPER_CASE_Z = 'Z';
	public static final char UPPER_CASE_TO_LOWER_CASE_OFFSET = (char)32;


	public static String capitalize(String string) {
		return changeFirstCharacterCase(string, true);
	}

	public static String uncapitalize(String string) {
		return changeFirstCharacterCase(string, false);
	}

	private static String changeFirstCharacterCase(String string, boolean capitalize) {
		if (string == null || string.length() == 0) {
			return string;
		}
		StringBuilder sb = new StringBuilder(string.length());
		if (capitalize) {
			sb.append(Character.toUpperCase(string.charAt(0)));
		}
		else {
			sb.append(Character.toLowerCase(string.charAt(0)));
		}
		sb.append(string.substring(1));
		return sb.toString();
	}

	public static String[] tokenizeToStringArray(String str, String delimiters) {
		return tokenizeToStringArray(str, delimiters, true, true);
	}

	public static String[] tokenizeToStringArray(
			String str, String delimiters, boolean trimTokens, boolean ignoreEmptyTokens) {

		if (str == null) {
			return null;
		}
		StringTokenizer st = new StringTokenizer(str, delimiters);
		List<String> tokens = new ArrayList<String>();
		while (st.hasMoreTokens()) {
			String token = st.nextToken();
			if (trimTokens) {
				token = token.trim();
			}
			if (!ignoreEmptyTokens || token.length() > 0) {
				tokens.add(token);
			}
		}
		return toStringArray(tokens);
	}

	public static String[] toStringArray(Collection<String> collection) {
		if (collection == null) {
			return null;
		}
		return collection.toArray(new String[collection.size()]);
	}

	public static boolean isEmpty(final CharSequence cs) {
		return cs == null || cs.length() == 0;
	}
}