Loading... # Java StringUtil工具类中isEmpty 和 isBlank 的用法区别 > **作者:Moshow郑锴,来源:blog.csdn.net/moshowgame/article/details/102914895** **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(" ")=false`** - StringUtils.isEmpty(null) = true - StringUtils.isEmpty("") = true - StringUtils.isEmpty(" ") = false - StringUtils.isEmpty(“bob”) = false - StringUtils.isEmpty(" bob ") = false ``` /** * * <p>NOTE: This method changed in Lang version 2.0. * It no longer trims the CharSequence. * That functionality is available in isBlank().</p> * * @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()`** ```java 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- ```java /** * @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** ```java /** * <p>Checks if none of the CharSequences are empty ("") or null.</p> * * <pre> * 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 * </pre> * * @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) { return !isAnyEmpty(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 ```java /** * <p>Checks if a CharSequence is whitespace, empty ("") or null.</p> * @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()`;** ```java 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 ```java /** * <p>Checks if any one of the CharSequences are blank ("") or null and not whitespace only..</p> * @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 ```java /** * <p>Checks if none of the CharSequences are blank ("") or null and whitespace only..</p> * @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](https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/StringUtils.html) 最后修改:2022 年 06 月 29 日 © 转载自他站 赞 如果觉得我的文章对你有用,请点个赞吧~