org.apache.commons.lang.StringUtils中提供许多有用的字符串操作方法，了解这些方法，我们可以避免许多不必要的重复工作。下面介绍其中比较有用的几个方法：
检查空字符串：
StringUtils.isBlank(String str);StringUtils.isNotBlank(String str); 缩写字符串：
String test = " This is a test of the abbreviation. " System.out.println( StringUtils.abbreviate( test, 10 ) );[Console输出]This is
查找嵌套字符串：
String htmlContent = " <html>/n " + " <head>/n " + " <title>Test Page</title>/n " + " </head>/n " + " <body>/n " + " <p>This is a TEST!</p>/n " + " </body>/n " + " </html> " ; // Extract the title from this XHTML content String title = StringUtils.substringBetween(htmlContent, " <title> " , " </title> " );System.out.println( " Title: " + title );[Console输出]Title: Test Page
验证字符串：
String test1 = " ORANGE " ;String test2 = " ICE9 " ;String test3 = " ICE CREAM " ;String test4 = " 820B Judson Avenue " ; boolean t1val = StringUtils.isAlpha( test1 ); // returns true boolean t2val = StringUtils.isAlphanumeric( test2 ); // returns true boolean t3val = StringUtils.isAlphaSpace( test3 ); // returns true boolean t4val = StringUtils.isAlphanumericSpace( test4 ); // returns true
计算字符串出现频率：
File manuscriptFile = new File( " manuscript.txt " );Reader reader = new FileReader( manuscriptFile );StringWriter stringWriter = new StringWriter( );
while ( reader.ready( ) ) { writer.write( reader.read( ) ); } 
String manuscript = stringWriter.toString( ); // Convert string to lowercase manuscript = StringUtils.lowerCase(manuscript); // count the occurrences of "futility" int numFutility = StringUtils.countMatches( manuscript, " futility " );
比较不同字符串：
int dist = StringUtils.getLevenshteinDistance( " Word " , " World " );String diff = StringUtils.difference( " Word " , " World " ); int index = StringUtils.indexOfDifference( " Word " , " World " );System.out.println( " Edit Distance: " + dist );System.out.println( " Difference: " + diff );System.out.println( " Diff Index: " + index );[Console输出]Edit Distance: 2 Difference: ldDiff Index: 3