TreeTemplate.java 文件源码

private ParserRuleContext parseQuery (String q) {
    // TODO replace AqlLexer with lexer for your Antlr4 grammar!
    Lexer qlLexer = new AqlLexer((CharStream) null);
    ParserRuleContext tree = null;
    // Like p. 111
    try {
        // Tokenize input data
        ANTLRInputStream input = new ANTLRInputStream(q);
        qlLexer.setInputStream(input);
        CommonTokenStream tokens = new CommonTokenStream(qlLexer);
        // TODO replace AqlParser with parser for your Antlr4
        // grammar!
        parser = new AqlParser(tokens);

        // Don't throw out erroneous stuff
        parser.setErrorHandler(new BailErrorStrategy());
        parser.removeErrorListeners();

        // Get starting rule from parser
        // TODO replace AqlParser with parser for your Antlr4
        // grammar!
        Method startRule = AqlParser.class.getMethod("start");
        tree = (ParserRuleContext) startRule
                .invoke(parser, (Object[]) null);
    }

    // Some things went wrong ...
    catch (Exception e) {
        System.err.println(e.getMessage());
    }

    // Return the generated tree
    return tree;
}