StringUtils测试

来源：http://blog.sina.com.cn/s/blog_621b6f0e0100tqaj.html

org.springframework.util.StringUtils

我们经常会对字符串进行操作，spring已经实现了常用的处理功能。我们可以使用org.springframework.util.StringUtils 工具类帮我们处理字符串。 工具类整理如下：   StringUtils.hasLength(null) = false   StringUtils.hasLength("") = false   StringUtils.hasLength(" ") = true   StringUtils.hasLength("Hello") = true      StringUtils.hasText(null) = false    StringUtils.hasText("") = false    StringUtils.hasText(" ") = false    StringUtils.hasText("12345") = true    StringUtils.hasText(" 12345 ") = true  //是否包含空白字符  StringUtils.containsWhitespace(null)=false  StringUtils.containsWhitespace("")=false  StringUtils.containsWhitespace("a")=false  StringUtils.containsWhitespace("abc")=false  StringUtils.containsWhitespace("abc")=false  StringUtils.containsWhitespace(" ")=true  StringUtils.containsWhitespace(" a")=true  StringUtils.containsWhitespace("abc ")=true  StringUtils.containsWhitespace("a b")=true  StringUtils.containsWhitespace("a  b")

 StringUtils.trimWhitespace(null)=null;  StringUtils.trimWhitespace("")="";  StringUtils.trimWhitespace(" ")="";  StringUtils.trimWhitespace("\t")="";  StringUtils.trimWhitespace(" a")="a";  StringUtils.trimWhitespace("a ")="a";  StringUtils.trimWhitespace(" a ")="a";  StringUtils.trimWhitespace(" a b ")="a b";

 StringUtils.trimLeadingWhitespace(null)=null;  StringUtils.trimLeadingWhitespace("")="";  StringUtils.trimLeadingWhitespace(" ")="";  StringUtils.trimLeadingWhitespace("\t")="";  StringUtils.trimLeadingWhitespace(" a")="a";  StringUtils.trimLeadingWhitespace("a ")="a ";  StringUtils.trimLeadingWhitespace(" a ")="a ";  StringUtils.trimLeadingWhitespace(" a b ")="a b "  StringUtils.trimLeadingWhitespace(" a b  c ")="a b  c "

 StringUtils.trimTrailingWhitespace(null)=null;  StringUtils.trimTrailingWhitespace(" ")="";  StringUtils.trimTrailingWhitespace("\t")="";  StringUtils.trimTrailingWhitespace("a ")="a";  StringUtils.trimTrailingWhitespace(" a")=" a";  StringUtils.trimTrailingWhitespace(" a ")=" a";  StringUtils.trimTrailingWhitespace(" a b ")=" a b";  StringUtils.trimTrailingWhitespace(" a b  c ")=" a b  c";

 StringUtils.trimAllWhitespace("")="";  StringUtils.trimAllWhitespace(" ")="";  StringUtils.trimAllWhitespace("\t")="";  StringUtils.trimAllWhitespace(" a")="a";  StringUtils.trimAllWhitespace("a ")="a";  StringUtils.trimAllWhitespace(" a ")="a";  StringUtils.trimAllWhitespace(" a b ")="ab";  StringUtils.trimAllWhitespace(" a b  c "="abc";  // 统计一个子字符串在字符串出现的次数  StringUtils.countOccurrencesOf(null, null) == 0;  StringUtils.countOccurrencesOf("s", null) == 0;  StringUtils.countOccurrencesOf(null, "s") == 0;  StringUtils.countOccurrencesOf("erowoiueoiur", "WERWER") == 0;  StringUtils.countOccurrencesOf("erowoiueoiur", "x")=0;  StringUtils.countOccurrencesOf("erowoiueoiur", " ") == 0;  StringUtils.countOccurrencesOf("erowoiueoiur", "") == 0;  StringUtils.countOccurrencesOf("erowoiueoiur", "e") == 2;  StringUtils.countOccurrencesOf("erowoiueoiur", "oi") == 2;  StringUtils.countOccurrencesOf("erowoiueoiur", "oiu") == 2;  StringUtils.countOccurrencesOf("erowoiueoiur", "oiur") == 1;  StringUtils.countOccurrencesOf("erowoiueoiur", "r") == 2;

 //字符串替换  String inString = "a6AazAaa77abaa";  String oldPattern = "aa";  String newPattern = "foo";  // Simple replace  String s = StringUtils.replace(inString, oldPattern, newPattern);  s.equals("a6AazAfoo77abfoo")=true;

 // Non match: no change  s = StringUtils.replace(inString, "qwoeiruqopwieurpoqwieur", newPattern);  s.equals(inString)=true  s = StringUtils.replace(inString, oldPattern, null);  s.equals(inString)=true

 // Null old pattern: should ignore  s = StringUtils.replace(inString, null, newPattern);         s.equals(inString)=true  //删除字符串

 String inString = "The quick brown fox jumped over the lazy dog";  String noThe = StringUtils.delete(inString, "the");  noThe.equals("The quick brown fox jumped over  lazy dog")=true;  String nohe = StringUtils.delete(inString, "he");  nohe.equals("T quick brown fox jumped over t lazy dog")=true;  String nosp = StringUtils.delete(inString, " ");  nosp.equals("Thequickbrownfoxjumpedoverthelazydog")=true;  String killEnd = StringUtils.delete(inString, "dog");  killEnd.equals("The quick brown fox jumped over the lazy ")=true;  String mismatch = StringUtils.delete(inString, "dxxcxcxog");   mismatch.equals(inString)=true;

 //删除任何字符  //源代码如下  //char c = inString.charAt(i);  //如果不存在 c 值，则返回 -1  //if (charsToDelete.indexOf(c) == -1) {  //out.append(c);  //}

 String inString = "Able was I ere I saw Elba";

 String res = StringUtils.deleteAny(inString, "I");         res.equals("Able was  ere  saw Elba")=true;  res = StringUtils.deleteAny(inString, "AeEba!");  res.equals("l ws I r I sw l")=true;  String mismatch = StringUtils.deleteAny(inString, "#@$#$^");  mismatch.equals(inString)=true;

 //源代码如下 return (str != null ? "'" + str + "'" : null);  assertEquals("'myString'", StringUtils.quote("myString"));  assertEquals("''", StringUtils.quote(""));  assertNull(StringUtils.quote(null));  //将第一个字符改大写  StringUtils.capitalize(Str)  //将第一个个字符改小写  StringUtils.uncapitalize(str)

 //mypath/myfile.txt" -> "myfile.txt  //获取字符串文件名和扩展名  StringUtils.getFilename("myfile").equals("myfile")=true;  StringUtils.getFilename("mypath/myfile".equals("myfile")=true;  StringUtils.getFilename("mypath/myfile".equals("myfile")=true;  StringUtils.getFilename("myfile.txt").equals("myfile.txt")=true;  StringUtils.getFilename("mypath/myfile.txt").equals("myfile.txt")=true;  // 获取字符串扩展名,以.分隔  StringUtils.getFilenameExtension("myfile")=null;  StringUtils.getFilenameExtension("myPath/myfile")=null;  StringUtils.getFilenameExtension("myfile.").equals("")=true;  StringUtils.getFilenameExtension("myPath/myfile.").equals("")=true;  StringUtils.StringUtils.getFilenameExtension("myfile.txt").equals("txt")=true;  StringUtils.getFilenameExtension("mypath/myfile.txt").equals("txt")=true;

 //舍去文件名扩展名  StringUtils.stripFilenameExtension(null)=true;  StringUtils.stripFilenameExtension("").equals("")=true;  StringUtils.stripFilenameExtension("myfile").equals("myfile")=true;  StringUtils.stripFilenameExtension("mypath/myfile").equals("mypath/myfile")=true;  StringUtils.stripFilenameExtension("myfile.").equals("myfile")=true;  StringUtils.stripFilenameExtension("mypath/myfile.").equals("mypath/myfile")=true;  StringUtils.stripFilenameExtension("mypath/myfile.").equals("mypath/myfile")=true;  StringUtils.stripFilenameExtension("myfile.txt").equals("myfile")=true;  StringUtils.stripFilenameExtension("mypath/myfile.txt").equals("mypath/myfile")=true

来源：http://blog.sina.com.cn/s/blog_621b6f0e0100tqaj.html