在Java中，实用程序类是一个定义一组执行常用功能的方法的类。这篇文章展示了最常用的Java实用程序类及其最常用的方法。类列表及其方法列表都按流行度排序。该数据基于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获得已经提供和流行的一些想法，这样您就不需要自己编程了。这些方法的名称通常表明它们的作用。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他们的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 ( )EMPTYtrimToNull ( )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 ( )EMPTYreplace ( )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_ARRAYsubarray ( )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_ARRAYEMPTY_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 ( )