Android Utililty Methods String Char Get

return str.charAt(index >= 0 ? index : str.length() + index);

StringBuffer sb = new StringBuffer();
int counter = 0;
for (int i = 0; i < str.length(); i++) {
    char c = str.charAt(i);
    sb.append(c);
    if (c < 255) {
        counter++;
    } else {
...

int counter = 0;
for (int i = 0; i < str.length(); i++) {
    char c = str.charAt(i);
    if (c < 255) {
        counter++;
    } else {
        counter = counter + 2;
return counter;

int num = 0;
for (int i = 0; i < str.length(); ++i) {
    if (str.charAt(i) - ch == 0) {
        num++;
return num;

if (!isChinese(ch)) {
    char[] charArray = ch.toCharArray();
    if (charArray.length > 0) {
        return charArray[0];
    } else {
        return 0;
byte[] bytes = new byte[2];
try {
    bytes = ch.getBytes("GB2312");
} catch (UnsupportedEncodingException e) {
    e.printStackTrace();
char result = '-';
int secPosValue = 0;
int i;
for (i = 0; i < bytes.length; i++) {
    bytes[i] -= GB_SP_DIFF;
secPosValue = bytes[0] * 100 + bytes[1];
for (i = 0; i < 23; i++) {
    if (secPosValue >= secPosValueList[i]
            && secPosValue < secPosValueList[i + 1]) {
        result = firstLetter[i];
        break;
return result;

String strPattern = "^[0-9a-zA-Z]*$";
Pattern p = Pattern.compile(strPattern);
Matcher m = p.matcher(strInput);
return m.matches();

int length = str.length();
if (length == 0) {
    return false;
for (int i = 0; i < length; i++) {
    if (!Character.isDigit(str.charAt(i))) {
        return false;
return true;

for (int i = 0; i < str.length(); i++) {
    if (!Character.isWhitespace(str.charAt(i))) {
        return false;
return true;