这篇文章展示了最常用的Java实用工具类及其最常用的方法。类列表及其方法列表均按受欢迎程度排序。数据基于从GitHub随机选择的50,000个开源Java项目。
希望您可以通过浏览列表来了解已经提供和流行的功能的一些想法，以使您知道不需要自己实现。这些方法的名称通常指示它们的作用。如果方法名称不够直观，您还可以查看其他开发人员如何在其开源项目中使用它们。
1.org.apache.commons.io.IOUtils
closeQuietly()
toString()
copy()
toByteArray()
write()
toInputStream()
readLines()
copyLarge()
lineIterator()
readFully()
2.org.apache.commons.io.FileUtils
deleteDirectory()
readFileToString()
deleteQuietly()
copyFile()
writeStringToFile()
forceMkdir()
write()
listFiles()
copyDirectory()
forceDelete()
3.org.apache.commons.lang.StringUtils
isBlank()
isNotBlank()
isEmpty()
isNotEmpty()
equals()
join()
split()
EMPTY
trimToNull()
replace()
4.org.apache.http.util.EntityUtils
toString()
consume()
toByteArray()
consumeQuietly()
getContentCharSet()
5.org.apache.commons.lang3.StringUtils
isBlank()
isNotBlank()
isEmpty()
isNotEmpty()
join()
equals()
split()
EMPTY
replace()
capitalize()
6.org.apache.commons.io.FilenameUtils
getExtension()
getBaseName()
getName()
concat()
removeExtension()
normalize()
wildcardMatch()
separatorsToUnix()
getFullPath()
isExtension()
7.org.springframework.util.StringUtils
hasText()
hasLength()
isEmpty()
commaDelimitedListToStringArray()
collectionToDelimitedString()
replace()
delimitedListToStringArray()
uncapitalize()
collectionToCommaDelimitedString()
tokenizeToStringArray()
8.org.apache.commons.lang.ArrayUtils
contains()
addAll()
clone()
isEmpty()
add()
EMPTY_BYTE_ARRAY
subarray()
indexOf()
isEquals()
toObject()
9.org.apache.commons.lang.StringEscapeUtils
escapeHtml()
unescapeHtml()
escapeXml()
escapeSql()
unescapeJava()
escapeJava()
escapeJavaScript()
unescapeXml()
unescapeJavaScript()
10.org.apache.http.client.utils.URLEncodedUtils
format()
parse()
11.org.apache.commons.codec.digest.DigestUtils
md5Hex()
shaHex()
sha256Hex()
sha1Hex()
sha()
md5()
sha512Hex()
sha1()
12.org.apache.commons.collections.CollectionUtils
isEmpty()
isNotEmpty()
select()
transform()
filter()
find()
collect()
forAllDo()
addAll()
isEqualCollection()
13.org.apache.commons.lang3.ArrayUtils
contains()
isEmpty()
isNotEmpty()
add()
clone()
addAll()
subarray()
indexOf()
EMPTY_OBJECT_ARRAY
EMPTY_STRING_ARRAY
14.org.apache.commons.beanutils.PropertyUtils
getProperty()
setProperty()
getPropertyDescriptors()
isReadable()
copyProperties()
getPropertyDescriptor()
getSimpleProperty()
isWriteable()
setSimpleProperty()
getPropertyType()
15.org.apache.commons.lang3.StringEscapeUtils
unescapeHtml4()
escapeHtml4()
escapeXml()
unescapeXml()
escapeJava()
escapeEcmaScript()
unescapeJava()
escapeJson()
escapeXml10()
16.org.apache.commons.beanutils.BeanUtils
copyProperties()
getProperty()
setProperty()
describe()
populate()
copyProperty()
cloneBean()
来源：https://www.programcreek.com/
