$re = '/ERROR ([^:]+): (.*)/';
$str = 'ERROR java.lang.NullPointerException: Sample Java Logback Exception
at Sample.errorLevel3(Sample.java:35)
at Sample.errorLevel4(Sample.java:34)
at Sample.errorLevel5(Sample.java:30)
at Sample.errorLevel6(Sample.java:3)';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php