public static boolean isAsciiControl(char ch) {
        return ch < 32 || ch == 127;
    }
<p>Checks whether the character is ASCII 7 bit control.</p>

<pre>
  CharUtils.isAsciiControl('a')  = false
  CharUtils.isAsciiControl('A')  = false
  CharUtils.isAsciiControl('3')  = false
  CharUtils.isAsciiControl('-')  = false
  CharUtils.isAsciiControl('\n') = true
  CharUtils.isAsciiControl('&copy;') = false
</pre>

@param ch  the character to check
@return true if less than 32 or equals 127
android/android_framework/base/src/main/java/lang3/CharUtils.java