当前位置:网站首页>isEmpty 和 isBlank 的用法区别
isEmpty 和 isBlank 的用法区别
2022-07-05 09:41:00 【沙漠一只雕得儿得儿】
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()
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
/**
* <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) {
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
/**
* <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();
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
/**
* <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
/**
* <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
边栏推荐
- 分布式数据库下子查询和 Join 等复杂 SQL 如何实现?
- 90%的人都不懂的泛型,泛型的缺陷和应用场景
- Cerebral Cortex:有向脑连接识别帕金森病中广泛存在的功能网络异常
- Tdengine already supports the industrial Intel edge insight package
- 宝塔面板MySQL无法启动
- RMS to EAP is simply implemented through mqtt
- 自动化规范检查软件如何发展而来?
- Unity粒子特效系列-毒液喷射预制体做好了,unitypackage包直接用 - 上
- MySQL数字类型学习笔记
- Hard core, have you ever seen robots play "escape from the secret room"? (code attached)
猜你喜欢
百度智能小程序巡檢調度方案演進之路
Those who are good at using soldiers, hide in the invisible, and explain the best promotional value works in depth in 90 minutes
From "chemist" to developer, from Oracle to tdengine, two important choices in my life
Roll up, break 35 - year - old Anxiety, animation Demonstration CPU recording Function call Process
剪掉ImageNet 20%数据量,模型性能不下降!Meta斯坦福等提出新方法,用知识蒸馏给数据集瘦身...
【小技巧】获取matlab中cdfplot函数的x轴,y轴的数值
Kotlin compose and native nesting
Mysql80 service does not start
Fluent generates icon prompt logo widget
How to implement complex SQL such as distributed database sub query and join?
随机推荐
(1) Complete the new construction of station in Niagara vykon N4 supervisor 4.8 software
Unity particle special effects series - the poison spray preform is ready, and the unitypackage package is directly used - on
美图炒币半年亏了3个亿,华为被曝在俄罗斯扩招,AlphaGo的同类又刷爆一种棋,今日更多大新闻在此...
oracle和mysql批量Merge对比
Viewpager pageradapter notifydatasetchanged invalid problem
Energy momentum: how to achieve carbon neutralization in the power industry?
. Net delay queue
C#函数返回多个值方法
Apache DolphinScheduler 系统架构设计
Understand the window query function of tdengine in one article
Jupiter notebook shortcut key
Flutter development: use safearea
A high density 256 channel electrode cap for dry EEG
Wechat applet - simple diet recommendation (4)
如何獲取GC(垃圾回收器)的STW(暫停)時間?
Matrix processing practice
从“化学家”到开发者,从甲骨文到 TDengine,我人生的两次重要抉择
[NTIRE 2022]Residual Local Feature Network for Efficient Super-Resolution
How to get the STW (pause) time of GC (garbage collector)?
Kotlin Compose 与原生 嵌套使用