java中驼峰与下划线写法互转的教程

packageday0704;

importjava.util.regex.Matcher;

importjava.util.regex.Pattern;

/**

* 驼峰法-下划线互转

* @author cshaper

* @since 2015.07.04

* @version 1.0.0

*/

publicclassUnderline2Camel {

/**

* 下划线转驼峰法

* @param line 源字符串

* @param smallCamel 大小驼峰,是否为小驼峰

* @return 转换后的字符串

*/

publicstaticString underline2Camel(String line,booleansmallCamel){

if(line==null||"".equals(line)){

return"";

}

StringBuffer sb=newStringBuffer();

Pattern pattern=Pattern.compile("([A-Za-z\d]+)(_)?");

Matcher matcher=pattern.matcher(line);

while(matcher.find()){

String word=matcher.group();

sb.append(smallCamel&&matcher.start()==0?Character.toLowerCase(word.charAt(0)):Character.toUpperCase(word.charAt(0)));

intindex=word.lastIndexOf('_');

if(index>0){

sb.append(word.substring(1, index).toLowerCase());

}else{

sb.append(word.substring(1).toLowerCase());

}

}

returnsb.toString();

}

/**

* 驼峰法转下划线

* @param line 源字符串

* @return 转换后的字符串

*/

publicstaticString camel2Underline(String line){

if(line==null||"".equals(line)){

return"";

}

line=String.valueOf(line.charAt(0)).toUpperCase().concat(line.substring(1));

StringBuffer sb=newStringBuffer();

Pattern pattern=Pattern.compile("[A-Z]([a-z\d]+)?");

Matcher matcher=pattern.matcher(line);

while(matcher.find()){

String word=matcher.group();

sb.append(word.toUpperCase());

sb.append(matcher.end()==line.length()?"":"_");

}

returnsb.toString();

}

publicstaticvoidmain(String[] args) {

String line="I_HAVE_AN_IPANG3_PIG";

String camel=underline2Camel(line,true);

System.out.println(camel);

System.out.println(camel2Underline(camel));

}

}