Here you can find the source of unicodeEscape(StringBuilder result, int in, int index)
private static int unicodeEscape(StringBuilder result, int in, int index)
//package com.java2s;
//License from project: Open Source License
public class Main {
static final char[] HEX_DIGITS = new char[] { '0', '1', '2', '3', '4',
'5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
/**/* w w w. jav a 2s . c o m*/
* Given a char, and its location in a StringBuilder,
* replace it with an escaped unicode if necessary
* @return The new index into StringBuilder
*/
private static int unicodeEscape(StringBuilder result, int in, int index) {
// utf8 within [32, 127] are fine
if (in >= 32 && in <= 127) {
return index;
}
if (in > '\uffff') {
final char[] surrogatePair = Character.toChars(in);
final String first = hex(surrogatePair[0]);
final String second = hex(surrogatePair[1]);
// ensure we have capacity to replace 2 chars
// (IE a surrogate pair) with \\u + first + \\u + second
result.ensureCapacity(result.capacity() + 2 + first.length()
+ second.length());
result.delete(index, index + 2);
result.insert(index++, '\\');
result.insert(index++, 'u');
result.insert(index, first);
index += first.length();
result.insert(index++, '\\');
result.insert(index++, 'u');
result.insert(index, second);
index += second.length() - 1;
} else {
// ensure we have capacity to replace 1 char with 6
result.ensureCapacity(result.capacity() + 5);
result.deleteCharAt(index);
result.insert(index++, '\\');
result.insert(index++, 'u');
result.insert(index++, HEX_DIGITS[in >> 12 & 15]);
result.insert(index++, HEX_DIGITS[in >> 8 & 15]);
result.insert(index++, HEX_DIGITS[in >> 4 & 15]);
result.insert(index, HEX_DIGITS[in & 15]);
}
return index;
}
private static String hex(int codepoint) {
return Integer.toHexString(codepoint).toUpperCase();
}
}