java正则表达式ReplaceAll不起作用

Question

我从另一个StackOverflow帖子上复制了这个代码。然而，我有一些问题。应替换与指定模式匹配的项目，但不替换

代码是：

protected String FixHexValuesInString(String str){
    Log.v(TAG, "before fix: "+ str);
    Matcher matcher = Pattern.compile("\\\\x([0-9a-f]{2})").matcher(str);
    while (matcher.find()) {
        int codepoint = Integer.valueOf(matcher.group(1), 16);
        Log.v(TAG, "matcher group 0: " + matcher.group(0));
        Log.v(TAG, "matcher group 1: " + matcher.group(1));
        str = str.replaceAll(matcher.group(0), String.valueOf((char) codepoint));
    }
    Log.v(TAG, " after fix: "+ str);
    return str;
}

下面是我写给LogCat的一个例子：

before fix: 'id': 1268, 'name': 'Reserva de Usos M\xfaltiples de la Cuenca del Lago de Atitl\xe1n-RUMCLA (Atitl\xe1n Watershed Multiple Use Reserve)'
matcher group 0: \xfa
matcher group 1: fa
matcher group 0: \xe1
matcher group 1: e1
matcher group 0: \xe1
matcher group 1: e1
 after fix: 'id': 1268, 'name': 'Reserva de Usos M\xfaltiples de la Cuenca del Lago de Atitl\xe1n-RUMCLA (Atitl\xe1n Watershed Multiple Use Reserve)'

有人知道为什么这样不行吗