import jdk.nashorn.internal.runtime.regexp.joni.Syntax; //导入依赖的package包/类
/**
 * Construct a Regular expression from the given {@code pattern} and {@code flags} strings.
 *
 * @param pattern RegExp pattern string
 * @param flags RegExp flag string
 * @throws ParserException if flags is invalid or pattern string has syntax error.
 */
public JoniRegExp(final String pattern, final String flags) throws ParserException {
    super(pattern, flags);

    int option = Option.SINGLELINE;

    if (this.isIgnoreCase()) {
        option |= Option.IGNORECASE;
    }
    if (this.isMultiline()) {
        option &= ~Option.SINGLELINE;
        option |= Option.NEGATE_SINGLELINE;
    }

    try {
        RegExpScanner parsed;

        try {
            parsed = RegExpScanner.scan(pattern);
        } catch (final PatternSyntaxException e) {
            // refine the exception with a better syntax error, if this
            // passes, just rethrow what we have
            Pattern.compile(pattern, 0);
            throw e;
        }

        if (parsed != null) {
            final char[] javaPattern = parsed.getJavaPattern().toCharArray();
            this.regex = new Regex(javaPattern, 0, javaPattern.length, option, Syntax.JAVASCRIPT);
            this.groupsInNegativeLookahead = parsed.getGroupsInNegativeLookahead();
        }
    } catch (final PatternSyntaxException | JOniException e2) {
        throwParserException("syntax", e2.getMessage());
    }
}
 

import jdk.nashorn.internal.runtime.regexp.joni.Syntax; //导入依赖的package包/类
/**
 * Construct a Regular expression from the given {@code pattern} and {@code flags} strings.
 *
 * @param pattern RegExp pattern string
 * @param flags RegExp flag string
 * @throws ParserException if flags is invalid or pattern string has syntax error.
 */
public JoniRegExp(final String pattern, final String flags) throws ParserException {
    super(pattern, flags);

    int option = Option.SINGLELINE;

    if (this.isIgnoreCase()) {
        option |= Option.IGNORECASE;
    }
    if (this.isMultiline()) {
        option &= ~Option.SINGLELINE;
        option |= Option.NEGATE_SINGLELINE;
    }

    try {
        RegExpScanner parsed;

        try {
            parsed = RegExpScanner.scan(pattern);
        } catch (final PatternSyntaxException e) {
            // refine the exception with a better syntax error, if this
            // passes, just rethrow what we have
            Pattern.compile(pattern, 0);
            throw e;
        }

        if (parsed != null) {
            char[] javaPattern = parsed.getJavaPattern().toCharArray();
            this.regex = new Regex(javaPattern, 0, javaPattern.length, option, Syntax.JAVASCRIPT);
            this.groupsInNegativeLookahead = parsed.getGroupsInNegativeLookahead();
        }
    } catch (final PatternSyntaxException | JOniException e2) {
        throwParserException("syntax", e2.getMessage());
    }
}