[scode type="share"]本文来源：blog.csdn.net/moshowgame/article/details/102914895[/scode]也许你两个都不知道，也许你除了isEmpty/isNotEmpty/isNotBlank/isBlank外，并不知道还有isAnyEmpty/isNoneEmpty/isAnyBlank/isNoneBlank的存在。come on ,让我们一起来探索org.apache.commons.lang3.StringUtils;这个工具类isEmpty系列StringUtils.isEmpty()是否为空. 可以看到 " " 空格是会绕过这种空判断,因为是一个空格,并不是严格的空值,会导致 isEmpty(" ")=falseStringUtils.isEmpty(null) = true StringUtils.isEmpty("") = true StringUtils.isEmpty(" ") = false StringUtils.isEmpty(“bob”) = false StringUtils.isEmpty(" bob ") = false / * * NOTE: This method changed in Lang version 2.0. * It no longer trims the CharSequence. * That functionality is available in isBlank(). * * @param cs the CharSequence to check, may be null * @return {@code true} if the CharSequence is empty or null * @since 3.0 Changed signature from isEmpty(String) to isEmpty(CharSequence) */ public static boolean isEmpty(final CharSequence cs) { return cs == null || cs.length() == 0; } StringUtils.isNotEmpty()相当于不为空 , = !isEmpty()public static boolean isNotEmpty(final CharSequence cs) { return !isEmpty(cs); } StringUtils.isAnyEmpty()是否有一个为空,只有一个为空,就为true.StringUtils.isAnyEmpty(null) = true StringUtils.isAnyEmpty(null, “foo”) = true StringUtils.isAnyEmpty("", “bar”) = true StringUtils.isAnyEmpty(“bob”, “”) = true StringUtils.isAnyEmpty(" bob ", null) = true StringUtils.isAnyEmpty(" ", “bar”) = false StringUtils.isAnyEmpty(“foo”, “bar”) = false / * @param css the CharSequences to check, may be null or empty * @return {@code true} if any of the CharSequences are empty or null * @since 3.2 */ public static boolean isAnyEmpty(final CharSequence... css) { if (ArrayUtils.isEmpty(css)) { return true; } for (final CharSequence cs : css){ if (isEmpty(cs)) { return true; } } return false; } StringUtils.isNoneEmpty()相当于!isAnyEmpty(css) , 必须所有的值都不为空才返回true/ * Checks if none of the CharSequences are empty ("") or null. * * * StringUtils.isNoneEmpty(null) = false * StringUtils.isNoneEmpty(null, "foo") = false * StringUtils.isNoneEmpty("", "bar") = false * StringUtils.isNoneEmpty("bob", "") = false * StringUtils.isNoneEmpty(" bob ", null) = false * StringUtils.isNoneEmpty(" ", "bar") = true * StringUtils.isNoneEmpty("foo", "bar") = true * * * @param css the CharSequences to check, may be null or empty * @return {@code true} if none of the CharSequences are empty or null * @since 3.2 */ public static boolean isNoneEmpty(final CharSequence... css) { isBank系列StringUtils.isBlank()是否为真空值(空格或者空值)StringUtils.isBlank(null) = true StringUtils.isBlank("") = true StringUtils.isBlank(" ") = true StringUtils.isBlank(“bob”) = false StringUtils.isBlank(" bob ") = false / * Checks if a CharSequence is whitespace, empty ("") or null. * @param cs the CharSequence to check, may be null * @return {@code true} if the CharSequence is null, empty or whitespace * @since 2.0 * @since 3.0 Changed signature from isBlank(String) to isBlank(CharSequence) */ public static boolean isBlank(final CharSequence cs) { int strLen; if (cs == null || (strLen = cs.length()) == 0) { return true; } for (int i = 0; i < strLen; i++) { if (Character.isWhitespace(cs.charAt(i)) == false) { return false; } } return true; } StringUtils.isNotBlank()是否真的不为空,不是空格或者空值 ,相当于!isBlank();public static boolean isNotBlank(final CharSequence cs) { return !isBlank(cs); } StringUtils.isAnyBlank()是否包含任何真空值(包含空格或空值)StringUtils.isAnyBlank(null) = true StringUtils.isAnyBlank(null, “foo”) = true StringUtils.isAnyBlank(null, null) = true StringUtils.isAnyBlank("", “bar”) = true StringUtils.isAnyBlank(“bob”, “”) = true StringUtils.isAnyBlank(" bob ", null) = true StringUtils.isAnyBlank(" ", “bar”) = true StringUtils.isAnyBlank(“foo”, “bar”) = false / * Checks if any one of the CharSequences are blank ("") or null and not whitespace only.. * @param css the CharSequences to check, may be null or empty * @return {@code true} if any of the CharSequences are blank or null or whitespace only * @since 3.2 */ public static boolean isAnyBlank(final CharSequence... css) { if (ArrayUtils.isEmpty(css)) { return true; } for (final CharSequence cs : css){ if (isBlank(cs)) { return true; } } return false; } StringUtils.isNoneBlank()是否全部都不包含空值或空格StringUtils.isNoneBlank(null) = false StringUtils.isNoneBlank(null, “foo”) = false StringUtils.isNoneBlank(null, null) = false StringUtils.isNoneBlank("", “bar”) = false StringUtils.isNoneBlank(“bob”, “”) = false StringUtils.isNoneBlank(" bob ", null) = false StringUtils.isNoneBlank(" ", “bar”) = false StringUtils.isNoneBlank(“foo”, “bar”) = true / * Checks if none of the CharSequences are blank ("") or null and whitespace only.. * @param css the CharSequences to check, may be null or empty * @return {@code true} if none of the CharSequences are blank or null or whitespace only * @since 3.2 */ public static boolean isNoneBlank(final CharSequence... css) { return !isAnyBlank(css); } StringUtils的其他方法可以参考官方的文档,里面有详细的描述,有些方法还是很好用的.https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/StringUtils.html