CommonLang 3におけるStringUtilsの最も完全な解析
19455 ワード
public static boolean isEmpty(CharSequence cs)
, "" null
StringUtils.isEmpty(null) = true StringUtils.isEmpty("") = true StringUtils.isEmpty(" ") = false StringUtils.isEmpty("bob") = false StringUtils.isEmpty(" bob ") = false
public static boolean isNotEmpty(CharSequence cs)
最も一般的な関数の1つで、上記の方法と比較します.StringUtils.isNotEmpty(null) = false StringUtils.isNotEmpty("") = false StringUtils.isNotEmpty(" ") = true StringUtils.isNotEmpty("bob") = true StringUtils.isNotEmpty(" bob ") = true
のいずれかのパラメータが空の場合、trueを返します.public static boolean isAnyEmpty(CharSequence... css)
これらのパラメータが空でない場合はfalseを返します.
いくつかの判断条件を書くとき、この方法はまだ実用的です.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
任意のパラメータが空でfalseを返しますpublic static boolean isNoneEmpty(CharSequence... css)
すべてのパラメータが空ではなく、trueを返します.
これらの方法の使い方に注意してください.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
文字オブジェクトが空の文字列かどうかを判断し、isEmptyとの違いに注意するpublic static boolean isBlank(CharSequence cs)
StringUtils.isBlank(null) = true StringUtils.isBlank("") = true StringUtils.isBlank(" ") = true StringUtils.isBlank("bob") = false StringUtils.isBlank(" bob ") = false
public static boolean isNotBlank(CharSequence cs)
StringUtils.isNotBlank(null) = false StringUtils.isNotBlank("") = false StringUtils.isNotBlank(" ") = false StringUtils.isNotBlank("bob") = true StringUtils.isNotBlank(" bob ") = true
原理は同じである.public static boolean isAnyBlank(CharSequence... css)
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
public static boolean isNoneBlank(CharSequence... css)
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
文字列の両端にある空の文字列、タブを削除public static String trim(String str)
char<=32如:t
空の場合は、空に戻ります
「」の場合StringUtils.trim(null) = null StringUtils.trim("") = "" StringUtils.trim(" ") = "" StringUtils.trim("abc") = "abc" StringUtils.trim(" abc ") = "abc"
バリエーションありpublic static String trimToNull(String str)
public static String trimToEmpty(String str)
よく使われないtrim()メソッドと似ていますpublic static String strip(String str)
str:処理された文字列、NULL可能public static String strip(String str, String stripChars)
stripChars:削除された文字列、StringUtils.strip(null, *) = null StringUtils.strip("", *) = "" StringUtils.strip("abc", null) = "abc" StringUtils.strip(" abc", null) = "abc" StringUtils.strip("abc ", null) = "abc" StringUtils.strip(" abc ", null) = "abc" StringUtils.strip(" abcyx", "xyz") = " abc"
public static boolean equals(CharSequence cs1, CharSequence cs2)
, , , 。
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
public static boolean equalsIgnoreCase(CharSequence str1, CharSequence str2)
( ), …… , 。
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
public static int indexOf(CharSequence seq, int searchChar)
indexOf , , ,
StringUtils.indexOf(null, *) = -1 StringUtils.indexOf("", *) = -1 StringUtils.indexOf("aabaabaa", 'a') = 0 StringUtils.indexOf("aabaabaa", 'b') = 2
public static int ordinalIndexOf(CharSequence str, CharSequence searchStr, int ordinal)
, Ordinal
StringUtils.ordinalIndexOf(null, *, *) = -1 StringUtils.ordinalIndexOf(*, null, *) = -1 StringUtils.ordinalIndexOf("", "", *) = 0 StringUtils.ordinalIndexOf("aabaabaa", "a", 1) = 0 StringUtils.ordinalIndexOf("aabaabaa", "a", 2) = 1 StringUtils.ordinalIndexOf("aabaabaa", "b", 1) = 2 StringUtils.ordinalIndexOf("aabaabaa", "b", 2) = 5 StringUtils.ordinalIndexOf("aabaabaa", "ab", 1) = 1 StringUtils.ordinalIndexOf("aabaabaa", "ab", 2) = 4 StringUtils.ordinalIndexOf("aabaabaa", "", 1) = 0 StringUtils.ordinalIndexOf("aabaabaa", "", 2) = 0
public static int lastIndexOf(CharSequence seq, int searchChar)
StringUtils.lastIndexOf(null, *) = -1 StringUtils.lastIndexOf("", *) = -1 StringUtils.lastIndexOf("aabaabaa", 'a') = 7 StringUtils.lastIndexOf("aabaabaa", 'b') = 5
public static int lastOrdinalIndexOf(CharSequence str, CharSequence searchStr, int ordinal)
searchStr str ordinal
StringUtils.lastOrdinalIndexOf(null, *, *) = -1 StringUtils.lastOrdinalIndexOf(*, null, *) = -1 StringUtils.lastOrdinalIndexOf("", "", *) = 0 StringUtils.lastOrdinalIndexOf("aabaabaa", "a", 1) = 7 StringUtils.lastOrdinalIndexOf("aabaabaa", "a", 2) = 6 StringUtils.lastOrdinalIndexOf("aabaabaa", "b", 1) = 5 StringUtils.lastOrdinalIndexOf("aabaabaa", "b", 2) = 2 StringUtils.lastOrdinalIndexOf("aabaabaa", "ab", 1) = 4 StringUtils.lastOrdinalIndexOf("aabaabaa", "ab", 2) = 1 StringUtils.lastOrdinalIndexOf("aabaabaa", "", 1) = 8 StringUtils.lastOrdinalIndexOf("aabaabaa", "", 2) = 8
文字列seqにsearchCharが含まれているかどうかpublic static boolean contains(CharSequence seq, int searchChar)
StringUtils.contains(null, *) = false StringUtils.contains("", *) = false StringUtils.contains("abc", 'a') = true StringUtils.contains("abc", 'z') = false
は、後の配列の任意のオブジェクトを含み、trueを返します.public static boolean containsAny(CharSequence cs, char... searchChars)
StringUtils.containsAny(null, *) = false StringUtils.containsAny("", *) = false StringUtils.containsAny(*, null) = false StringUtils.containsAny(*, []) = false StringUtils.containsAny("zzabyycdxx",['z','a']) = true StringUtils.containsAny("zzabyycdxx",['b','y']) = true StringUtils.containsAny("aba", ['z']) = false
public static String substring(String str, int start)
StringUtils.substring(null, *) = null StringUtils.substring("", *) = "" StringUtils.substring("abc", 0) = "abc" StringUtils.substring("abc", 2) = "c" StringUtils.substring("abc", 4) = "" StringUtils.substring("abc", -2) = "bc" StringUtils.substring("abc", -4) = "abc"
public static String left(String str, int len)
public static String right(String str, int len)
の3つの方法は、文字列の切り取りに似ています.public static String mid(String str, int pos, int len)
public static String[] split(String str, String separatorChars)
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"]
public static
String join(T... elements)
StringUtils.join(null) = null StringUtils.join([]) = "" StringUtils.join([null]) = "" StringUtils.join(["a", "b", "c"]) = "abc" StringUtils.join([null, "", "a"]) = "a"
public static String join(Object[] array, char separator)
, ,
StringUtils.join(null, *) = null StringUtils.join([], *) = "" StringUtils.join([null], *) = "" StringUtils.join(["a", "b", "c"], ';') = "a;b;c" StringUtils.join(["a", "b", "c"], null) = "abc" StringUtils.join([null, "", "a"], ';') = ";;a"
public static String deleteWhitespace(String str)
StringUtils.deleteWhitespace(null) = null StringUtils.deleteWhitespace("") = "" StringUtils.deleteWhitespace("abc") = "abc" StringUtils.deleteWhitespace(" ab c ") = "abc"
public static String removeStart(String str, String remove)
, , 。
StringUtils.removeStart(null, *) = null StringUtils.removeStart("", *) = "" StringUtils.removeStart(*, null) = * StringUtils.removeStart("www.domain.com", "www.") = "domain.com" StringUtils.removeStart("domain.com", "www.") = "domain.com" StringUtils.removeStart("www.domain.com", "domain") = "www.domain.com" StringUtils.removeStart("abc", "") = "abc"
public static String rightPad(String str, int size, char padChar)
, 。 。
StringUtils.rightPad(null, *, *) = null StringUtils.rightPad("", 3, 'z') = "zzz" StringUtils.rightPad("bat", 3, 'z') = "bat" StringUtils.rightPad("bat", 5, 'z') = "batzz" StringUtils.rightPad("bat", 1, 'z') = "bat" StringUtils.rightPad("bat", -1, 'z') = "bat"
public static String leftPad(String str, int size, char padChar)
StringUtils.leftPad(null, *, *) = null StringUtils.leftPad("", 3, 'z') = "zzz" StringUtils.leftPad("bat", 3, 'z') = "bat" StringUtils.leftPad("bat", 5, 'z') = "zzbat" StringUtils.leftPad("bat", 1, 'z') = "bat" StringUtils.leftPad("bat", -1, 'z') = "bat"
public static String center(String str, int size)
,
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 "
public static String capitalize(String str)
StringUtils.capitalize(null) = null StringUtils.capitalize("") = "" StringUtils.capitalize("cat") = "Cat" StringUtils.capitalize("cAt") = "CAt"
public static String swapCase(String str)
StringUtils.swapCase(null) = null StringUtils.swapCase("") = "" StringUtils.swapCase("The dog has a BONE") = "tHE DOG HAS A bone"
public static boolean isAlpha(CharSequence cs)
StringUtils.isAlpha(null) = false StringUtils.isAlpha("") = false StringUtils.isAlpha(" ") = false StringUtils.isAlpha("abc") = true StringUtils.isAlpha("ab2c") = false StringUtils.isAlpha("ab-c") = false
public static String defaultString(String str, String defaultStr)
, , ,
StringUtils.defaultString(null, "NULL") = "NULL" StringUtils.defaultString("", "NULL") = "" StringUtils.defaultString("bat", "NULL") = "bat"
public static String reverse(String str)
StringUtils.reverse(null) = null StringUtils.reverse("") = "" StringUtils.reverse("bat") = "tab"
public static String abbreviate(String str, int maxWidth)
,
。maxWith 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
public static String abbreviate(String str, int offset, int maxWidth)
StringUtils.abbreviate(null, *, *) = null StringUtils.abbreviate("", 0, 4) = "" StringUtils.abbreviate("abcdefghijklmno", -1, 10) = "abcdefg..." StringUtils.abbreviate("abcdefghijklmno", 0, 10) = "abcdefg..." StringUtils.abbreviate("abcdefghijklmno", 1, 10) = "abcdefg..." StringUtils.abbreviate("abcdefghijklmno", 4, 10) = "abcdefg..." StringUtils.abbreviate("abcdefghijklmno", 5, 10) = "...fghi..." StringUtils.abbreviate("abcdefghijklmno", 6, 10) = "...ghij..." StringUtils.abbreviate("abcdefghijklmno", 8, 10) = "...ijklmno" StringUtils.abbreviate("abcdefghijklmno", 10, 10) = "...ijklmno" StringUtils.abbreviate("abcdefghijklmno", 12, 10) = "...ijklmno" StringUtils.abbreviate("abcdefghij", 0, 3) = IllegalArgumentException StringUtils.abbreviate("abcdefghij", 5, 6) = IllegalArgumentException
public static String wrap(String str, char wrapWith)
,
StringUtils.wrap(null, *) = null StringUtils.wrap("", *) = "" StringUtils.wrap("ab", '\0') = "ab" StringUtils.wrap("ab", 'x') = "xabx" StringUtils.wrap("ab", '\'') = "'ab'" StringUtils.wrap("\"ab\"", '\"') = "\"\"ab\"\""