commons-lang3-StringUtils

字符串工具类

abbreviate(string str, int maxwidth) 返回一个指定长度加省略号的字符串，maxwidth必须大于3

stringutils.abbreviate(null, *)      = null

stringutils.abbreviate("", 4)        = ""

stringutils.abbreviate("abcdefg", 6) = "abc..."

stringutils.abbreviate("abcdefg", 7) = "abcdefg"

stringutils.abbreviate("abcdefg", 8) = "abcdefg"

stringutils.abbreviate("abcdefg", 4) = "a..."

stringutils.abbreviate("abcdefg", 3) = illegalargumentexception

abbreviate(string str, int offset, int maxwidth) 返回一个指定长度加省略号的字符串，maxwidth必须大于3

abbreviate(string str, string abbrevmarker, int maxwidth) 返回一个自定义省略号的指定长度字符串，maxwidth必须大于3

stringutils.abbreviate(null, "...", *)      = null

stringutils.abbreviate("abcdefg", null, *)  = "abcdefg"

stringutils.abbreviate("", "...", 4)        = ""

stringutils.abbreviate("abcdefg", ".", 5)   = "abcd."

stringutils.abbreviate("abcdefg", ".", 7)   = "abcdefg"

stringutils.abbreviate("abcdefg", ".", 8)   = "abcdefg"

stringutils.abbreviate("abcdefg", "..", 4)  = "ab.."

stringutils.abbreviate("abcdefg", "..", 3)  = "a.."

stringutils.abbreviate("abcdefg", "..", 2)  = illegalargumentexception

stringutils.abbreviate("abcdefg", "...", 3) = illegalargumentexception

abbreviatemiddle(string str, string abbrevmarker, int maxwidth) 将字符串缩短到指定长度（length），字符串的中间部分用替换字符串（middle）显示

stringutils.abbreviatemiddle("abc", null, 0)      = "abc"

stringutils.abbreviatemiddle("abc", ".", 0)      = "abc"

stringutils.abbreviatemiddle("abc", ".", 3)      = "abc"

stringutils.abbreviatemiddle("abcdef", ".", 4)     = "ab.f"

appendifmissing(string str, charsequence suffix, charsequence... suffixes) 如果str不是以任何suffixes结尾，将字符串suffix拼接到字符串str后面

stringutils.appendifmissing(null, null) = null

stringutils.appendifmissing("abc", null) = "abc"

stringutils.appendifmissing("", "xyz") = "xyz"

stringutils.appendifmissing("abc", "xyz") = "abcxyz"

stringutils.appendifmissing("abcxyz", "xyz") = "abcxyz"

stringutils.appendifmissing("abcxyz", "xyz") = "abcxyzxyz"

appendifmissingignorecase(string str, charsequence suffix, charsequence... suffixes) 同上 不区分大小写

capitalize(string str) 将字符串第一个字符大写并返回

center(string str, int size) 用空格字符填充使字符串str位于长度为size的大字符串中间

stringutils.center(null, *)   = null

stringutils.center("", 4)     = "    "

stringutils.center("ab", -1)  = "ab"

stringutils.center("ab", 4)   = " ab "

stringutils.center("abcd", 2) = "abcd"

stringutils.center("a", 4)    = " a  "

center(string str, int size, char padchar) 用指定字符填充使字符串str位于长度为size的大字符串中间

chomp(string str) 删除字符串末尾的一个换行符,返回一个新的字符串（换行符"n", "r", or "rn"）

stringutils.chomp(null)          = null

stringutils.chomp("")            = ""

stringutils.chomp("abc \r")      = "abc "

stringutils.chomp("abc\n")       = "abc"

stringutils.chomp("abc\r\n")     = "abc"

stringutils.chomp("abc\r\n\r\n") = "abc\r\n"

stringutils.chomp("abc\n\r")     = "abc\n"

stringutils.chomp("abc\n\rabc")  = "abc\n\rabc"

stringutils.chomp("\r")          = ""

stringutils.chomp("\n")          = ""

stringutils.chomp("\r\n")        = ""

chop(string str) 删除字符串末尾的一个字符，返回一个新的字符串

stringutils.chop(null)          = null

stringutils.chop("")            = ""

stringutils.chop("abc \r")      = "abc "

stringutils.chop("abc\n")       = "abc"

stringutils.chop("abc\r\n")     = "abc"

stringutils.chop("abc")         = "ab"

stringutils.chop("abc\nabc")    = "abc\nab"

stringutils.chop("a")           = ""

stringutils.chop("\r")          = ""

stringutils.chop("\n")          = ""

stringutils.chop("\r\n")        = ""

compare(string str1, string str2) 比较两个字符串，返回一个int值

str1等于str2（或都为空）返回0

str1小于str2返回小于0

str1大于str2返回大于0

 

stringutils.compare(null, null)   = 0

stringutils.compare(null , "a")   < 0

stringutils.compare("a", null)    > 0

stringutils.compare("abc", "abc") = 0

stringutils.compare("a", "b")     < 0

stringutils.compare("b", "a")     > 0

stringutils.compare("a", "b")     > 0

stringutils.compare("ab", "abc")  < 0

contains(charsequence seq, charsequence searchseq) 检查字符串中是否包含指定字符，返回boolean

stringutils.contains(null, *)     = false

stringutils.contains(*, null)     = false

stringutils.contains("", "")      = true

stringutils.contains("abc", "")   = true

stringutils.contains("abc", "a")  = true

stringutils.contains("abc", "z")  = false

containsany(charsequence cs, charsequence... searchcharsequences) 检查字符串中是否包含任一字符，返回boolean

stringutils.containsany(null, *)            = false

stringutils.containsany("", *)              = false

stringutils.containsany(*, null)            = false

stringutils.containsany(*, [])              = false

stringutils.containsany("abcd", "ab", null) = true

stringutils.containsany("abcd", "ab", "cd") = true

stringutils.containsany("abc", "d", "abc")  = true

containsnone(charsequence cs, string invalidchars) 检查字符串不包含指定字符，返回boolean

stringutils.containsnone(null, *)       = true

stringutils.containsnone(*, null)       = true

stringutils.containsnone("", *)         = true

stringutils.containsnone("ab", "")      = true

stringutils.containsnone("abab", "xyz") = true

stringutils.containsnone("ab1", "xyz")  = true

stringutils.containsnone("abz", "xyz")  = false

containsonly(charsequence cs, string validchars) 检查字符串只包含特定的字符，返回boolean

stringutils.containsonly(null, *)       = false

stringutils.containsonly(*, null)       = false

stringutils.containsonly("", *)         = true

stringutils.containsonly("ab", "")      = false

stringutils.containsonly("abab", "abc") = true

stringutils.containsonly("ab1", "abc")  = false

stringutils.containsonly("abz", "abc")  = false

containswhitespace(charsequence seq) 检查字符串中是否包含空格字符，返回boolean

countmatches(charsequence str, charsequence sub) 检查字符串中出现指定字符的次数，返回一个int值

stringutils.countmatches(null, *)       = 0

stringutils.countmatches("", *)         = 0

stringutils.countmatches("abba", null)  = 0

stringutils.countmatches("abba", "")    = 0

stringutils.countmatches("abba", "a")   = 2

stringutils.countmatches("abba", "ab")  = 1

stringutils.countmatches("abba", "xxx") = 0

defaultifblank(t str, t defaultstr) 如果字符串为null、空（""），或全是空格，将返回指定字符串，否则返回原值

stringutils.defaultifblank(null, "null")  = "null"

stringutils.defaultifblank("", "null")    = "null"

stringutils.defaultifblank(" ", "null")   = "null"

stringutils.defaultifblank("bat", "null") = "bat"

stringutils.defaultifblank("", null)      = null

defaultifempty(t str, t defaultstr) 如果字符串为null、空（""），将返回指定字符串，否则返回原值

stringutils.defaultifempty(null, "null")  = "null"

stringutils.defaultifempty("", "null")    = "null"

stringutils.defaultifempty(" ", "null")   = " "

stringutils.defaultifempty("bat", "null") = "bat"

stringutils.defaultifempty("", null)      = null

defaultstring(string str) 如果字符串为null，将返回空的字符串（""），否则返回原值

stringutils.defaultstring(null)  = ""

stringutils.defaultstring("")    = ""

stringutils.defaultstring("bat") = "bat"

defaultstring(string str, string defaultstr) 如果字符串为null，将返回指定字符，否则返回原值

stringutils.defaultstring(null, "null")  = "null"

stringutils.defaultstring("", "null")    = ""

stringutils.defaultstring("bat", "null") = "bat"

deletewhitespace(string str) 删除字符串中的空格字符，并返回新的字符串

stringutils.deletewhitespace(null)         = null

stringutils.deletewhitespace("")           = ""

stringutils.deletewhitespace("abc")        = "abc"

stringutils.deletewhitespace("   ab  c  ") = "abc"

difference(string str1, string str2) 比较两个字符串差异，并返回差异的字符，返回第二个字符串的剩余部分，这意味着“abc”和“ab”之间的区别是空字符串而不是“c”。

stringutils.difference(null, null) = null

stringutils.difference("", "") = ""

stringutils.difference("", "abc") = "abc"

stringutils.difference("abc", "") = ""

stringutils.difference("abc", "abc") = ""

stringutils.difference("abc", "ab") = ""

stringutils.difference("ab", "abxyz") = "xyz"

stringutils.difference("abcde", "abxyz") = "xyz"

stringutils.difference("abcde", "xyz") = "xyz"

endswith(charsequence str, charsequence suffix) 检查字符串是否以指定字符结尾，返回一个boolean

stringutils.endswith(null, null)      = true

stringutils.endswith(null, "def")     = false

stringutils.endswith("abcdef", null)  = false

stringutils.endswith("abcdef", "def") = true

stringutils.endswith("abcdef", "def") = false

stringutils.endswith("abcdef", "cde") = false

stringutils.endswith("abcdef", "")    = true

endswithany(charsequence sequence, charsequence... searchstrings) 检查字符串是否以指定字符数组结尾，返回一个boolean

stringutils.endswithany(null, null)      = false

stringutils.endswithany(null, new string[] {"abc"})  = false

stringutils.endswithany("abcxyz", null)     = false

stringutils.endswithany("abcxyz", new string[] {""}) = true

stringutils.endswithany("abcxyz", new string[] {"xyz"}) = true

stringutils.endswithany("abcxyz", new string[] {null, "xyz", "abc"}) = true

stringutils.endswithany("abcxyz", "def", "xyz") = true

stringutils.endswithany("abcxyz", "def", "xyz") = false

endswithignorecase(charsequence str, charsequence suffix) 检查字符串是否以指定字符（不区分大小写）结尾，返回一个boolean

stringutils.endswithignorecase(null, null)      = true

stringutils.endswithignorecase(null, "def")     = false

stringutils.endswithignorecase("abcdef", null)  = false

stringutils.endswithignorecase("abcdef", "def") = true

stringutils.endswithignorecase("abcdef", "def") = true

stringutils.endswithignorecase("abcdef", "cde") = false

equals(charsequence cs1, charsequence cs2) 比较两个字符串是否相等，返回一个boolean

stringutils.equals(null, null)   = true

stringutils.equals(null, "abc")  = false

stringutils.equals("abc", null)  = false

stringutils.equals("abc", "abc") = true

stringutils.equals("abc", "abc") = false

equalsanyignorecase(charsequence string, charsequence... searchstrings) 比较两个字符串是否相等（不区分大小写），返回一个boolean

stringutils.equalsignorecase(null, null)   = true

stringutils.equalsignorecase(null, "abc")  = false

stringutils.equalsignorecase("abc", null)  = false

stringutils.equalsignorecase("abc", "abc") = true

stringutils.equalsignorecase("abc", "abc") = true

equalsany(charsequence string, charsequence... searchstrings) 比较字符串是否与指定字符串数组中某一值相等，返回一个boolean

stringutils.equalsany(null, (charsequence[]) null) = false

stringutils.equalsany(null, null, null)    = true

stringutils.equalsany(null, "abc", "def")  = false

stringutils.equalsany("abc", null, "def")  = false

stringutils.equalsany("abc", "abc", "def") = true

stringutils.equalsany("abc", "abc", "def") = false

equalsanyignorecase(charsequence string, charsequence... searchstrings) 比较字符串是否与指定字符串数组中某一值相等（不区分大小写），返回一个boolean

stringutils.equalsanyignorecase(null, (charsequence[]) null) = false

stringutils.equalsanyignorecase(null, null, null)    = true

stringutils.equalsanyignorecase(null, "abc", "def")  = false

stringutils.equalsanyignorecase("abc", null, "def")  = false

stringutils.equalsanyignorecase("abc", "abc", "def") = true

stringutils.equalsanyignorecase("abc", "abc", "def") = true

getcommonprefix(string... strs) 获取字符串数组元素公共字符，返回string

stringutils.getcommonprefix(null) = ""

stringutils.getcommonprefix(new string[] {}) = ""

stringutils.getcommonprefix(new string[] {"abc"}) = "abc"

stringutils.getcommonprefix(new string[] {null, null}) = ""

stringutils.getcommonprefix(new string[] {"", ""}) = ""

stringutils.getcommonprefix(new string[] {"", null}) = ""

stringutils.getcommonprefix(new string[] {"abc", null, null}) = ""

stringutils.getcommonprefix(new string[] {null, null, "abc"}) = ""

stringutils.getcommonprefix(new string[] {"", "abc"}) = ""

stringutils.getcommonprefix(new string[] {"abc", ""}) = ""

stringutils.getcommonprefix(new string[] {"abc", "abc"}) = "abc"

stringutils.getcommonprefix(new string[] {"abc", "a"}) = "a"

stringutils.getcommonprefix(new string[] {"ab", "abxyz"}) = "ab"

stringutils.getcommonprefix(new string[] {"abcde", "abxyz"}) = "ab"

stringutils.getcommonprefix(new string[] {"abcde", "xyz"}) = ""

stringutils.getcommonprefix(new string[] {"xyz", "abcde"}) = ""

stringutils.getcommonprefix(new string[] {"i am a machine", "i am a robot"}) = "i am a "

indexof(charsequence seq, charsequence searchseq) 检查指定字符在字符串中出现的位置，返回一个int值

stringutils.indexof(null, *)          = -1

stringutils.indexof(*, null)          = -1

stringutils.indexof("", "")           = 0

stringutils.indexof("", *)            = -1 (except when * = "")

stringutils.indexof("aabaabaa", "a")  = 0

stringutils.indexof("aabaabaa", "b")  = 2

stringutils.indexof("aabaabaa", "ab") = 1

stringutils.indexof("aabaabaa", "")   = 0

indexofignorecase(charsequence seq, charsequence searchseq) 检查指定字符在字符串中出现的位置（不区分大小写），返回一个int值

isallblank(charsequence... css) 检查数组所有字符是否为null、empty、或全是空格字符，返回一个boolean

stringutils.isallblank(null)             = true

stringutils.isallblank(null, "foo")      = false

stringutils.isallblank(null, null)       = true

stringutils.isallblank("", "bar")        = false

stringutils.isallblank("bob", "")        = false

stringutils.isallblank("  bob  ", null)  = false

stringutils.isallblank(" ", "bar")       = false

stringutils.isallblank("foo", "bar")     = false

stringutils.isallblank(new string[] {})  = true

isallempty(charsequence... css) 检查数组所有字符是否为null、empty，返回一个boolean

stringutils.isallempty(null)             = true

stringutils.isallempty(null, "")         = true

stringutils.isallempty(new string[] {})  = true

stringutils.isallempty(null, "foo")      = false

stringutils.isallempty("", "bar")        = false

stringutils.isallempty("bob", "")        = false

stringutils.isallempty("  bob  ", null)  = false

stringutils.isallempty(" ", "bar")       = false

stringutils.isallempty("foo", "bar")     = false

isalllowercase(charsequence cs) 检查字符串中所有字符是否是小写，返回一个boolean

isalluppercase(charsequence cs) 检查字符串中所有字符是否是大写，返回一个boolean

isanyblank(charsequence... css) 检查数组中字符串是否有一个为null、empty或全是空格字符，返回一个boolean

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(new string[] {})  = false

stringutils.isanyblank(new string[]{""}) = true

stringutils.isanyblank("foo", "bar")     = false

isanyempty(charsequence... css) 检查数组中字符串是否有一个为null、empty，返回一个boolean

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

stringutils.isanyempty(new string[]{})   = false

stringutils.isanyempty(new string[]{""}) = true

isblank(charsequence cs) 检查字符串是否为null、empty或空格字符，返回一个boolean

stringutils.isblank(null)      = true

stringutils.isblank("")        = true

stringutils.isblank(" ")       = true

stringutils.isblank("bob")     = false

stringutils.isblank("  bob  ") = false

isempty(charsequence cs) 检查字符串是否为null、empty，返回一个boolean

stringutils.isempty(null)      = true

stringutils.isempty("")        = true

stringutils.isempty(" ")       = false

stringutils.isempty("bob")     = false

stringutils.isempty("  bob  ") = false

isnotblank(charsequence cs) 检查字符串是否不为null、empty或空格字符，返回一个boolean

isnotempty(charsequence cs) 检查字符串是否不为null、empty，返回一个boolean

isnumeric(charsequence cs) 检查字符串是否是数字，返回一个boolean

stringutils.isnumeric(null)   = false

stringutils.isnumeric("")     = false

stringutils.isnumeric("  ")   = false

stringutils.isnumeric("123")  = true

stringutils.isnumeric("१२३")  = true

stringutils.isnumeric("12 3") = false

stringutils.isnumeric("ab2c") = false

stringutils.isnumeric("12-3") = false

stringutils.isnumeric("12.3") = false

stringutils.isnumeric("-123") = false

stringutils.isnumeric("+123") = false

iswhitespace(charsequence cs) 检查字符串是否是空格字符，返回一个boolean

stringutils.iswhitespace(null)   = false

stringutils.iswhitespace("")     = true

stringutils.iswhitespace("  ")   = true

stringutils.iswhitespace("abc")  = false

stringutils.iswhitespace("ab2c") = false

stringutils.iswhitespace("ab-c") = false

join(byte[] array, char separator) 将字节数组转换成string，以指定字符分隔

stringutils.join(null, *)               = null

stringutils.join([], *)                 = ""

stringutils.join([null], *)             = ""

stringutils.join([1, 2, 3], ';')  = "1;2;3"

stringutils.join([1, 2, 3], null) = "123"

char、double、float、int、long、short、object、t同理

joinwith(string separator, object... objects) 将多个元素已指定字符分隔拼接成string

stringutils.joinwith(",", {"a", "b"})        = "a,b"

stringutils.joinwith(",", {"a", "b",""})     = "a,b,"

stringutils.joinwith(",", {"a", null, "b"})  = "a,,b"

stringutils.joinwith(null, {"a", "b"})       = "ab"

lastindexof(charsequence seq, charsequence searchseq) 获取指定字符在字符串中的最后一个索引位置

stringutils.lastindexof(null, *)          = -1

stringutils.lastindexof(*, null)          = -1

stringutils.lastindexof("", "")           = 0

stringutils.lastindexof("aabaabaa", "a")  = 7

stringutils.lastindexof("aabaabaa", "b")  = 5

stringutils.lastindexof("aabaabaa", "ab") = 4

stringutils.lastindexof("aabaabaa", "")   = 8

left(string str, int len) 返回从左边开始指定大小的字符串

stringutils.left(null, *)    = null

stringutils.left(*, -ve)     = ""

stringutils.left("", *)      = ""

stringutils.left("abc", 0)   = ""

stringutils.left("abc", 2)   = "ab"

stringutils.left("abc", 4)   = "abc"

right(string str, int len) 同上相反

length(charsequence cs) 获取字符串大小，返回一个int

lowercase(string str) 将字符串转换为小写，返回一个string

stringutils.lowercase(null)  = null

stringutils.lowercase("")    = ""

stringutils.lowercase("abc") = "abc"

uppercase(string str) 同上相反

mid(string str, int pos, int len) 获取字符串指定位置区间的字符，返回一个string

stringutils.mid(null, *, *)    = null

stringutils.mid(*, *, -ve)     = ""

stringutils.mid("", 0, *)      = ""

stringutils.mid("abc", 0, 2)   = "ab"

stringutils.mid("abc", 0, 4)   = "abc"

stringutils.mid("abc", 2, 4)   = "c"

stringutils.mid("abc", 4, 2)   = ""

stringutils.mid("abc", -2, 2)  = "ab"

overlay(string str, string overlay, int start, int end) 在字符串位置区间插入指定字符，返回一个string

stringutils.overlay(null, *, *, *)            = null

stringutils.overlay("", "abc", 0, 0)          = "abc"

stringutils.overlay("abcdef", null, 2, 4)     = "abef"

stringutils.overlay("abcdef", "", 2, 4)       = "abef"

stringutils.overlay("abcdef", "", 4, 2)       = "abef"

stringutils.overlay("abcdef", "zzzz", 2, 4)   = "abzzzzef"

stringutils.overlay("abcdef", "zzzz", 4, 2)   = "abzzzzef"

stringutils.overlay("abcdef", "zzzz", -1, 4)  = "zzzzef"

stringutils.overlay("abcdef", "zzzz", 2, 8)   = "abzzzz"

stringutils.overlay("abcdef", "zzzz", -2, -3) = "zzzzabcdef"

stringutils.overlay("abcdef", "zzzz", 8, 10)  = "abcdefzzzz"

prependifmissing(string str, charsequence prefix, charsequence... prefixes) 在字符串最左边插入指定字符，如果已存在，将不插入，返回一个string

stringutils.prependifmissing(null, null) = null

stringutils.prependifmissing("abc", null) = "abc"

stringutils.prependifmissing("", "xyz") = "xyz"

stringutils.prependifmissing("abc", "xyz") = "xyzabc"

stringutils.prependifmissing("xyzabc", "xyz") = "xyzabc"

stringutils.prependifmissing("xyzabc", "xyz") = "xyzxyzabc"

prependifmissingignorecase(string str, charsequence prefix, charsequence... prefixes) 同上，只是不区分大小写

remove(string str, char remove) 删除字符串中指定字符，返回一个string

stringutils.remove(null, *)       = null

stringutils.remove("", *)         = ""

stringutils.remove("queued", 'u') = "qeed"

stringutils.remove("queued", 'z') = "queued"

removeignorecase(string str, string remove) 同上，只是不区分大小写

removeall(string text, string regex) 根据匹配规则删除所有字符，返回一个string

stringutils.removeall(null, *)      = null

stringutils.removeall("any", null)  = "any"

stringutils.removeall("any", "")    = "any"

stringutils.removeall("any", ".*")  = ""

stringutils.removeall("any", ".+")  = ""

stringutils.removeall("abc", ".?")  = ""

stringutils.removeall("a<__>\n<__>b", "<.*>")      = "a\nb"

stringutils.removeall("a<__>\n<__>b", "(?s)<.*>")  = "ab"

stringutils.removeall("abcabc123abc", "[a-z]")     = "abc123"

removeend(string str, string remove) 删除字符串结尾指定字符，返回一个string

stringutils.removeend(null, *)      = null

stringutils.removeend("", *)        = ""

stringutils.removeend(*, null)      = *

stringutils.removeend("www.domain.com", ".com.")  = "www.domain.com"

stringutils.removeend("www.domain.com", ".com")   = "www.domain"

stringutils.removeend("www.domain.com", "domain") = "www.domain.com"

stringutils.removeend("abc", "")    = "abc"

removestart(string str, string remove) 同上相反

removeendignorecase(string str, string remove) 同上，只是不区分大小写

removefirst(string text, string regex) 根据匹配规则删除第一次出现的字符，返回一个string

stringutils.removefirst(null, *)      = null

stringutils.removefirst("any", null)  = "any"

stringutils.removefirst("any", "")    = "any"

stringutils.removefirst("any", ".*")  = ""

stringutils.removefirst("any", ".+")  = ""

stringutils.removefirst("abc", ".?")  = "bc"

stringutils.removefirst("a<__>\n<__>b", "<.*>")      = "a\n<__>b"

stringutils.removefirst("a<__>\n<__>b", "(?s)<.*>")  = "ab"

stringutils.removefirst("abcabc123", "[a-z]")          = "abcbc123"

stringutils.removefirst("abcabc123abc", "[a-z]+")      = "abc123abc"

repeat(string str, int repeat) 将字符重复指定次数拼接成新的字符串，返回一个string

stringutils.repeat(null, 2) = null

stringutils.repeat("", 0)   = ""

stringutils.repeat("", 2)   = ""

stringutils.repeat("a", 3)  = "aaa"

stringutils.repeat("ab", 2) = "abab"

stringutils.repeat("a", -2) = ""

replace(string text, string searchstring, string replacement) 用replacement替换字符串中的所有searchstring，返回一个string

stringutils.replace(null, *, *)        = null

stringutils.replace("", *, *)          = ""

stringutils.replace("any", null, *)    = "any"

stringutils.replace("any", *, null)    = "any"

stringutils.replace("any", "", *)      = "any"

stringutils.replace("aba", "a", null)  = "aba"

stringutils.replace("aba", "a", "")    = "b"

stringutils.replace("aba", "a", "z")   = "zbz"

reverse(string str) 将字符串反转，返回一个string

stringutils.reverse(null)  = null

stringutils.reverse("")    = ""

stringutils.reverse("bat") = "tab"

reversedelimited(string str, char separatorchar) 将字符串指定分隔符出的字符反转

stringutils.reversedelimited(null, *)      = null

  stringutils.reversedelimited("", *)        = ""

  stringutils.reversedelimited("a.b.c", 'x') = "a.b.c"

  stringutils.reversedelimited("a.b.c", ".") = "c.b.a"

split(string str, string separatorchars) 将字符串以指定字符分隔，返回数组

stringutils.split(null, *)         = null

stringutils.split("", *)           = []

stringutils.split("abc def", null) = ["abc", "def"]

stringutils.split("abc def", " ")  = ["abc", "def"]

stringutils.split("abc  def", " ") = ["abc", "def"]

stringutils.split("ab:cd:ef", ":") = ["ab", "cd", "ef"]

substring(string str, int start) 将字符串从指定位置区间截取，返回string

swapcase(string str) 将字符串大小写互转，返回一个string

stringutils.swapcase(null)                 = null

stringutils.swapcase("")                   = ""

stringutils.swapcase("the dog has a bone") = "the dog has a bone"

toencodedstring(byte[] bytes, charset charset) 将字符串转为指定编码格式，返回一个string

trim(string str) 去除字符串空格

trimtoempty(string str) 去除字符串空格，null转为empty，返回一个string

stringutils.trimtoempty(null)          = ""

stringutils.trimtoempty("")            = ""

stringutils.trimtoempty("     ")       = ""

stringutils.trimtoempty("abc")         = "abc"

stringutils.trimtoempty("    abc    ") = "abc"

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来源：csdn

原文：