private String findPackage() {
        Matcher matcher = PATTERN_FIND_PACKAGE.matcher(content);
        if (matcher.find()) {
            return matcher.group();
        }
        return null;
    }
private String findPackage() {
        Matcher matcher = PATTERN_FIND_PACKAGE.matcher(content);
        if (matcher.find()) {
            return matcher.group();
        }
        return null;
    }
private String findPackage ( ) { Matcher matcher = PATTERN_FIND_PACKAGE . matcher ( content ) ; if ( matcher . find ( ) ) { return matcher . group ( ) ; } return null ; }
---------------------------------------- 包定义和导入包 ----------------------------------------
---------------------------------------- 包定义和导入包 ----------------------------------------