JavaScript正则表达式到Java正则表达式-替换和lambda

return phoneStr.replace(/[a-zA-Z]/g, function(m) {
    var ix= m[0].toLowerCase().charCodeAt(0)-0x61; // ASCII 'a'
    return '22233344455566677778889999'.charAt(ix);
});

StringBuffer b= new StringBuffer();
Matcher m= Pattern.compile("[A-Za-z]").matcher(phoneStr);
while (m.find()) {
    int ix= (int) (m.group(0).toLowerCase().charAt(0)-'a');
    m.appendReplacement(b, "22233344455566677778889999".substring(ix, ix+1));
}
m.appendTail(b);
return b.toString();

char[] c= phoneStr.toLowerCase().toCharArray();
for (int i= 0; i<c.length; i++)
    if (c[i]>='a' && c[i]<='z')
        c[i]= "22233344455566677778889999".charAt((int) (c[i]-'a'));
return new String(c);

String replaceCharsByNumbers(String stringToChange) {
    return stringToChange
            .replace('a', '2')
            .replace('b', '2')
            .replace('c', '2')
            .replace('d', '3')
            .replace('e', '3')
            .replace('f', '3')
            .replace('g', '4')
            .replace('h', '4')
            .replace('i', '4')
            .replace('j', '5')
            .replace('k', '5')
            .replace('l', '5')
            .replace('m', '6')
            .replace('n', '6')
            .replace('o', '6')
            .replace('p', '7')
            .replace('q', '7')
            .replace('r', '7')
            .replace('s', '7')
            .replace('t', '8')
            .replace('u', '8')
            .replace('v', '8')
            .replace('w', '9')
            .replace('x', '9')
            .replace('y', '9')
            .replace('z', '9');
}