public static int toIntValue(char ch, int defaultValue) {
        if (isAsciiNumeric(ch) == false) {
            return defaultValue;
        }
        return ch - 48;
    }
<p>Converts the character to the Integer it represents, throwing an
exception if the character is not numeric.</p>

<p>This method coverts the char '1' to the int 1 and so on.</p>

<pre>
  CharUtils.toIntValue('3', -1)  = 3
  CharUtils.toIntValue('A', -1)  = -1
</pre>

@param ch  the character to convert
@param defaultValue  the default value to use if the character is not numeric
@return the int value of the character
android/android_framework/base/src/main/java/lang3/CharUtils.java