StringUtils

StringUtils

package com.java.study.test.unit7;

/**
 * String常用工具类
 */
public class StringUtils {

	/**
	 * 为空
	 * @param str
	 * @return
	 */
	public static boolean isEmpty(String str) {
		return str == null || str.length() == 0;
	}

	/**
	 * 非空
	 * @param str
	 * @return
	 */
	public static boolean isNotEmpty(String str) {
		return !isEmpty(str);
	}
    
	/**
	 * 为空，判断空字符
	 * @param str
	 * @return
	 */
	public static boolean isBlank(String str) {
		int strLen;
		if (str == null || (strLen = str.length()) == 0)
			return true;
		for (int i = 0; i < strLen; i++)
			if (!Character.isWhitespace(str.charAt(i)))
				return false;

		return true;
	}

	public static boolean isNotBlank(String str) {
		return !isBlank(str);
	}

	public static String trim(String str) {
		return str != null ? str.trim() : null;
	}

	public static String trimToNull(String str) {
		String ts = trim(str);
		return isEmpty(ts) ? null : ts;
	}

	public static String trimToEmpty(String str) {
		return str != null ? str.trim() : "";
	}

	public static String strip(String str) {
		return strip(str, null);
	}

	public static String stripToNull(String str) {
		if (str == null) {
			return null;
		} else {
			str = strip(str, null);
			return str.length() != 0 ? str : null;
		}
	}

	public static String stripToEmpty(String str) {
		return str != null ? strip(str, null) : "";
	}

	public static String strip(String str, String stripChars) {
		if (isEmpty(str)) {
			return str;
		} else {
			str = stripStart(str, stripChars);
			return stripEnd(str, stripChars);
		}
	}

	public static String stripStart(String str, String stripChars) {
		int strLen;
		if (str == null || (strLen = str.length()) == 0)
			return str;
		int start = 0;
		if (stripChars == null) {
			for (; start != strLen && Character.isWhitespace(str.charAt(start)); start++)
				;
		} else {
			if (stripChars.length() == 0)
				return str;
			for (; start != strLen
					&& stripChars.indexOf(str.charAt(start)) != -1; start++)
				;
		}
		return str.substring(start);
	}

	public static String stripEnd(String str, String stripChars) {
		int end;
		if (str == null || (end = str.length()) == 0)
			return str;
		if (stripChars == null) {
			for (; end != 0 && Character.isWhitespace(str.charAt(end - 1)); end--)
				;
		} else {
			if (stripChars.length() == 0)
				return str;
			for (; end != 0 && stripChars.indexOf(str.charAt(end - 1)) != -1; end--)
				;
		}
		return str.substring(0, end);
	}

	public static String[] stripAll(String strs[]) {
		return stripAll(strs, null);
	}

	public static String[] stripAll(String strs[], String stripChars) {
		int strsLen;
		if (strs == null || (strsLen = strs.length) == 0)
			return strs;
		String newArr[] = new String[strsLen];
		for (int i = 0; i < strsLen; i++)
			newArr[i] = strip(strs[i], stripChars);

		return newArr;
	}

	public static boolean equals(String str1, String str2) {
		return str1 != null ? str1.equals(str2) : str2 == null;
	}

	public static boolean equalsIgnoreCase(String str1, String str2) {
		return str1 != null ? str1.equalsIgnoreCase(str2) : str2 == null;
	}

	public static int indexOf(String str, char searchChar) {
		if (isEmpty(str))
			return -1;
		else
			return str.indexOf(searchChar);
	}

	public static int indexOf(String str, char searchChar, int startPos) {
		if (isEmpty(str))
			return -1;
		else
			return str.indexOf(searchChar, startPos);
	}

	public static int indexOf(String str, String searchStr) {
		if (str == null || searchStr == null)
			return -1;
		else
			return str.indexOf(searchStr);
	}

}