public class StringUtils
extends java.lang.Object
| 限定符和类型 | 字段和说明 |
|---|---|
static java.lang.String |
EMPTY
The empty String
"". |
static java.lang.String[] |
EMPTY_STRING_ARRAY
一个空字符串数组.
|
| 构造器和说明 |
|---|
StringUtils() |
| 限定符和类型 | 方法和说明 |
|---|---|
static int |
asciiSizeInBytes(long v)
计算一个Long类型的数字的文本长度.
|
static java.lang.String |
build(java.lang.String delimiter,
java.lang.String prefix,
java.lang.String suffix,
java.lang.String... strings)
拼接字符串.
|
static byte[] |
bytes(java.lang.CharSequence str)
编码字符串
使用系统默认编码 |
static byte[] |
bytes(java.lang.CharSequence str,
java.nio.charset.Charset charset)
编码字符串
|
static boolean |
isEmpty(java.lang.String text)
检测字符串是否为 null或"".
|
static boolean |
isNotEmpty(java.lang.String text)
检测字符串是否不为 null且不为"".
|
static java.lang.String |
join(java.lang.String... strings)
拼接字符串.
|
static int |
length(java.lang.String text)
检测一个字符串长度.
|
static java.lang.String |
lowerWord(java.lang.CharSequence cs,
char c)
将一个字符串由驼峰式命名变成分割符分隔单词
lowerWord("helloWorld", '_') => "hello_world"
|
static java.lang.String[] |
split(java.lang.String str,
java.lang.String separatorChars)
Splits the provided text into an array, separators specified.
|
static byte[] |
utf8Bytes(java.lang.CharSequence str)
编码字符串,编码为UTF-8
|
public static final java.lang.String EMPTY
"".public static final java.lang.String[] EMPTY_STRING_ARRAY
public static boolean isEmpty(java.lang.String text)
检测字符串是否为 null或"".
StringUtils.isEmpty(null) = true
StringUtils.isEmpty("") = true
StringUtils.isEmpty(" ") = false
StringUtils.isEmpty("test") = false
StringUtils.isEmpty(" test ") = false
text - 被检测字符串public static boolean isNotEmpty(java.lang.String text)
检测字符串是否不为 null且不为"".
StringUtils.isNotEmpty(null) = false
StringUtils.isNotEmpty("") = false
StringUtils.isNotEmpty(" ") = true
StringUtils.isNotEmpty("test") = true
StringUtils.isNotEmpty(" test ") = true
text - 被检测字符串public static int length(java.lang.String text)
字符串有可能包含中文等其他文字,中文应该算2个长度.
text - 被检测字符串public static java.lang.String[] split(java.lang.String str,
java.lang.String separatorChars)
Splits the provided text into an array, separators specified. This is an alternative to using StringTokenizer.
The separator is not included in the returned String array. Adjacent separators are treated as one separator. For more control over the split use the StrTokenizer class.
A null input String returns null. A null
separatorChars splits on whitespace.
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"]
str - the String to parse, may be nullseparatorChars - the characters used as the delimiters, null
splits on whitespacenull if null String inputpublic static java.lang.String lowerWord(java.lang.CharSequence cs,
char c)
lowerWord("helloWorld", '_') => "hello_world"
cs - 字符串c - 分隔符public static int asciiSizeInBytes(long v)
包含负数计算
v - Long类型的数字public static java.lang.String join(java.lang.String... strings)
strings - 需要拼接的字串public static java.lang.String build(java.lang.String delimiter,
java.lang.String prefix,
java.lang.String suffix,
java.lang.String... strings)
在比较长或多的情况计算长度比StringJoiner性能好.
StringJoiner result = new StringJoiner(delimiter, prefix, suffix);
for (String str : strings) {
result.add(str);
}
return result.toString();
Stream.of(strings).collect(Collectors.joining(delimiter, prefix, suffix))
delimiter - 分隔符prefix - 前缀suffix - 后缀strings - 需要拼接的字串public static byte[] utf8Bytes(java.lang.CharSequence str)
str - 字符串public static byte[] bytes(java.lang.CharSequence str)
str - 字符串public static byte[] bytes(java.lang.CharSequence str,
java.nio.charset.Charset charset)
str - 字符串charset - 字符集,如果此字段为空,则编码的结果取决于平台