// substitute "a\b" for XYZ or ABC in input
String rep = "a\\\\b";
String input = "> XYZ <=> ABC <";
Pattern pattern = Pattern.compile ("ABC|XYZ");
Matcher matcher = pattern.matcher (input);
System.out.println (matcher.replaceFirst (rep));
System.out.println (matcher.replaceAll (rep));
// change all newlines in input to escaped, DOS-like CR/LF
rep = "\\\\r\\\\n";
input = "line 1\nline 2\nline 3\n";
pattern = Pattern.compile ("\\n");
matcher = pattern.matcher (input);
System.out.println ("");
System.out.println ("Before:");
System.out.println (input);
System.out.println ("After (dos-ified, escaped):");
System.out.println (matcher.replaceAll (rep));
