JAVA过滤特殊字符

public class StringFilter {

public static String validaString(String in){

StringBuffer out = new StringBuffer(); // Used to hold the output.
char current; // Used to reference the current character.

if (in == null || ("".equals(in)))
return ""; // vacancy test.
for (int i = 0; i < in.length(); i++) {
current = in.charAt(i); // NOTE: No IndexOutOfBoundsException caught
// here; it should not happen.
if ((current == 0x9) || (current == 0xA)
|| ((current >= 0x20) && (current <= 0xD7FF))
|| ((current >= 0xE000) && (current <= 0xFFFD))
|| ((current >= 0x10000) && (current <= 0x10FFFF)))
out.append(current);
}
return out.toString();
}