org.apache.commons.lang
Class StringUtils
java.lang.Object
org.apache.commons.lang.StringUtils
public class StringUtilsextends Object
Operations on String that are null safe.
- IsEmpty/IsBlank - checks if a String contains text
- Trim/Strip - removes leading and trailing whitespace
- Equals - compares two strings null-safe
- startsWith - check if a String starts with a prefix null-safe
- endsWith - check if a String ends with a suffix null-safe
- IndexOf/LastIndexOf/Contains - null-safe index-of checks
- IndexOfAny/LastIndexOfAny/IndexOfAnyBut/LastIndexOfAnyBut - index-of any of a set of Strings
- ContainsOnly/ContainsNone/ContainsAny - does String contains only/none/any of these characters
- Substring/Left/Right/Mid - null-safe substring extractions
- SubstringBefore/SubstringAfter/SubstringBetween - substring extraction relative to other strings
- Split/Join - splits a String into an array of substrings and vice versa
- Remove/Delete - removes part of a String
- Replace/Overlay - Searches a String and replaces one String with another
- Chomp/Chop - removes the last part of a String
- LeftPad/RightPad/Center/Repeat - pads a String
- UpperCase/LowerCase/SwapCase/Capitalize/Uncapitalize - changes the case of a String
- CountMatches - counts the number of occurrences of one String in another
- IsAlpha/IsNumeric/IsWhitespace/IsAsciiPrintable - checks the characters in a String
- DefaultString - protects against a null input String
- Reverse/ReverseDelimited - reverses a String
- Abbreviate - abbreviates a string using ellipsis
- Difference - compares Strings and reports on their differences
- LevensteinDistance - the number of changes needed to change one String into another
The StringUtils class defines certain words related to String handling.
- null -
null - empty - a zero-length string (
"") - space - the space character (
‘ ‘, char 32) - whitespace - the characters defined by
Character.isWhitespace(char) - trim - the characters <= 32 as in
String.trim()
StringUtils handles null input Strings quietly. That is to say that a null input will return null. Where a boolean or int is being returned details vary by method.
A side effect of the null handling is that a NullPointerException should be considered a bug in StringUtils (except for deprecated methods).
Methods in this class give sample code to explain their operation. The symbol * is used to indicate any input including null.
翻译:Google
org.apache.commons.lang
类StringUtils
java.lang.Object
org.apache.commons.lang.StringUtils
公共类StringUtils扩展Object
这样做的操作String是 null安全的。
- IsEmpty / IsBlank - 检查一个String是否包含文本
- 修剪/去除 - 去除前导和尾随的空白
- 等于 - 比较两个字符串无效
- startsWith - 检查一个字符串是否以一个前缀为null开头
- endsWith - 检查一个String是否以一个后缀为null结尾
- IndexOf / LastIndexOf / Contains - 无效索引的检查
- IndexOfAny / LastIndexOfAny / IndexOfAnyBut / LastIndexOfAnyBut - 索引 - 任何一组字符串
- ContainsOnly / ContainsNone / ContainsAny - 是String只包含/ none /任何这些字符
- 子字符串/左/右/中 - 零安全子串提取
- SubstringBefore / SubstringAfter / SubstringBetween - 相对于其他字符串的子字符串提取
- 拆分/连接 - 将一个字符串拆分为一个子字符串数组，反之亦然
- 删除/删除 - 删除部分字符串
- 替换/覆盖 - 搜索一个字符串并用另一个替换一个字符串
- Chomp / Chop - 删除字符串的最后部分
- 左键盘/右键盘/中心/重复 - 填充字符串
- UpperCase / LowerCase / SwapCase / Capitalize / Uncapitalize - 更改字符串的大小写
- CountMatches - 统计另一个字符串的出现次数
- IsAlpha / IsNumeric / IsWhitespace / IsAsciiPrintable - 检查字符串中的字符
- DefaultString - 防止空输入字符串
- Reverse / ReverseDelimited - 反转字符串
- 缩写 - 使用省略号缩写字符串
- 差异 - 比较字符串和报告差异
- LevensteinDistance - 将一个字符串更改为另一个字符串所需的更改次数
在StringUtils类定义与字符串处理某些词。
- 空值 -
null - 空 - 一个零长度的字符串（
""） - 空格 - 空格字符（
‘ ‘char 32） - 空格 - 由...定义的字符
Character.isWhitespace(char) - 修剪 - 在<= 32的字符
String.trim()
StringUtilsnull静静地处理输入字符串。这就是说，一个null输入将返回null。在哪里boolean或int正在退货的细节因方法而异。
处理的一个副作用null是a NullPointerException应该被认为是一个错误 StringUtils（除了被弃用的方法）。
这个类中的方法给出了示例代码来解释它们的操作。该符号*用于指示包括的任何输入null。
检查字符串是否为空
isNotEmpty 将空格也作为参数，isNotBlank 则排除空格参数
isNoneEmpty 可添加多个参数将空格也作为参数 , isNoneBlank 可添加多个参数,排除空格参数 去掉字符串前后的空白Trim/Strip 比较两个字符串是否相等Equals 检查字符串是否以null前缀为开头startsWith 检查字符串是否以null后缀为结尾 检查字符串是否包含一个特定的字符IndexOf / LastIndexOf / Contains
原文地址：https://www.cnblogs.com/yccmelody/p/8117318.html