StringUtils.tokenizeToStringArray()

讀Spring源碼的時候，遇到這么個東西，記錄一下

BeanDefinitionParserDelegate

	/**
	 * Parses the supplied {@code <bean>} element. May return {@code null}
	 * if there were errors during parse. Errors are reported to the
	 * {@link org.springframework.beans.factory.parsing.ProblemReporter}.
	 */
	@Nullable
	public BeanDefinitionHolder parseBeanDefinitionElement(Element ele, @Nullable BeanDefinition containingBean) {
		// 解析ID屬性
		String id = ele.getAttribute(ID_ATTRIBUTE);
		// 解析Name屬性
		String nameAttr = ele.getAttribute(NAME_ATTRIBUTE);

		List<String> aliases = new ArrayList<>();
		if (StringUtils.hasLength(nameAttr)) {
			String[] nameArr = StringUtils.tokenizeToStringArray(nameAttr, MULTI_VALUE_ATTRIBUTE_DELIMITERS);
			aliases.addAll(Arrays.asList(nameArr));
		}

　　

將字符串按照指定的字符轉換成String[]數組，如字符串中不包含指定字符，則將整個字符串放進數組。如指定字符有多個，是分別按單個字符來切割的。 字符串： "made,in;china"     指定字符： ",;"       返回數組：[made, in, china]

	/**
	 * Tokenize the given {@code String} into a {@code String} array via a
	 * {@link StringTokenizer}.
	 * <p>Trims tokens and omits empty tokens.
	 * <p>The given {@code delimiters} string can consist of any number of
	 * delimiter characters. Each of those characters can be used to separate
	 * tokens. A delimiter is always a single character; for multi-character
	 * delimiters, consider using {@link #delimitedListToStringArray}.
	 * @param str the {@code String} to tokenize (potentially {@code null} or empty)
	 * @param delimiters the delimiter characters, assembled as a {@code String}
	 * (each of the characters is individually considered as a delimiter)
	 * @return an array of the tokens
	 * @see java.util.StringTokenizer
	 * @see String#trim()
	 * @see #delimitedListToStringArray
	 */
	public static String[] tokenizeToStringArray(@Nullable String str, String delimiters) {
		return tokenizeToStringArray(str, delimiters, true, true);
	}

	/**
	 * Tokenize the given {@code String} into a {@code String} array via a
	 * {@link StringTokenizer}.
	 * <p>The given {@code delimiters} string can consist of any number of
	 * delimiter characters. Each of those characters can be used to separate
	 * tokens. A delimiter is always a single character; for multi-character
	 * delimiters, consider using {@link #delimitedListToStringArray}.
	 * @param str the {@code String} to tokenize (potentially {@code null} or empty)
	 * @param delimiters the delimiter characters, assembled as a {@code String}
	 * (each of the characters is individually considered as a delimiter)
	 * @param trimTokens trim the tokens via {@link String#trim()}
	 * @param ignoreEmptyTokens omit empty tokens from the result array
	 * (only applies to tokens that are empty after trimming; StringTokenizer
	 * will not consider subsequent delimiters as token in the first place).
	 * @return an array of the tokens
	 * @see java.util.StringTokenizer
	 * @see String#trim()
	 * @see #delimitedListToStringArray
	 */
	public static String[] tokenizeToStringArray(
			@Nullable String str, String delimiters, boolean trimTokens, boolean ignoreEmptyTokens) {

		if (str == null) {
			return new String[0];
		}

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

　　

 

測試代碼：

public class MyTest {

	public static final String MULTI_VALUE_ATTRIBUTE_DELIMITERS = ",; ";
	@Test
	public void test() {
		String nameAttr = "made,in;china";
		String flag = MULTI_VALUE_ATTRIBUTE_DELIMITERS;
		String[] nameArr = StringUtils.tokenizeToStringArray(nameAttr, MULTI_VALUE_ATTRIBUTE_DELIMITERS);
		System.out.println(Arrays.toString(nameArr));
	}
	@Test
	public void test2() {
		String nameAttr = "madeinchina";
		String flag = MULTI_VALUE_ATTRIBUTE_DELIMITERS;
		String[] nameArr = StringUtils.tokenizeToStringArray(nameAttr, MULTI_VALUE_ATTRIBUTE_DELIMITERS);
		System.out.println(Arrays.toString(nameArr));
	}
}

test輸出結果：[made, in, china]

test2輸出結果：[madeinchina]