举例：String fName =” G:\Java_Source\navigation_tigra_menu\demo1\img\lev1_arrow.gif ”
方法一：
1 File tempFile =new File( fName.trim());
2 String fileName = tempFile.getName();
方法二：
String fName = fName.trim();
String fileName = fName.subString(fName.lastIndexOf("/")+1);
方法三：
1 String fName = fName.trim();
2
3 String temp[] = fName.split("\\\\"); /**split里面必须是正则表达式，"\\"的作用是对字符串转义*/
4
5 String fileName = temp[temp.length-1];
方法四：
1 String regEx ="[^\\\\:]+?\\..*$";
2 String s = "G:lev1_arrow.gif";
3 Pattern pat = Pattern.compile(regEx);
4 Matcher mat = pat.matcher(s);
5 boolean rs = mat.find();
6 System.out.println(rs);
7 for(int i=0; i <= mat.groupCount(); i++){
8 System.out.println(mat.group(i));
9 }