Meta-characters predefined to match specific characters. : Introduction « Regular Expressions « Java Tutorial

\\A single backslash
\0nAn octal value describing a character, where n is a number such that 0 <= n <= 7
\0mnnThe character with octal value 0mnn (0 <= m <= 3, 0 <= n <= 7)
\0nnThe character with octal value 0nn (0 <= n <= 7)
\0xhhThe character with hexadecimal value hh (where 0 <= h <= F)
\uhhhhThe character with hexadecimal value hhhh (where 0 <= h <= F)
\tA tab (character '\u0009')
\nA newline (linefeed) ('\u000A')
\rA carriage-return ('\u000D')
\fA form-feed ('\u000C')
\aA bell/beep character ('\u0007')
\eAn escape character ('\u001B')
\cxThe control character corresponding to x, such as \cc is control-c
.Any single character

8.1.1.Meta-characters predefined to match specific characters.
8.1.2.Meta-characters to match against certain string boundaries.
8.1.3.Regular expression languages also have character classes.
8.1.4.POSIX character classes and Java character classes
8.1.5.Java Character Class
8.1.6.Match a particular character a specified number of times.
8.1.7.Read regular expression from console
8.1.8.Regex Test Harness
8.1.9.Match Java source file and file and class name
8.1.10.Finding all words that start with an 'a'
8.1.11.Simple validation using the Pattern and Matcher objects
8.1.12.A possessive qualifier
8.1.13.Find the starting point of the second 'Bond'
8.1.14.A negative look ahead
8.1.15.A negative behind ahead
8.1.16.A positive look ahead
8.1.17.Pattern helper
8.1.18.Escapes characters that have special meaning to regular expressions