Examples with UnionStatement org.apache.jackrabbit.oak.query.xpath.Statement.UnionStatement used on opensource projects

Example 1 with UnionStatement

use of org.apache.jackrabbit.oak.query.xpath.Statement.UnionStatement in project jackrabbit-oak by apache.

the class XPathToSQL2Converter method convertToUnion.

private Statement convertToUnion(String query, Statement statement, int startParseIndex) throws ParseException {
    int start = query.indexOf("(", startParseIndex);
    String begin = query.substring(0, start);
    XPathToSQL2Converter converter = new XPathToSQL2Converter();
    String partList = query.substring(start);
    converter.initialize(partList);
    converter.read();
    int lastParseIndex = converter.parseIndex;
    int lastOrIndex = lastParseIndex;
    converter.read("(");
    int level = 0;
    ArrayList<String> parts = new ArrayList<String>();
    int parseIndex;
    while (true) {
        parseIndex = converter.parseIndex;
        if (converter.readIf("(")) {
            level++;
        } else if (converter.readIf(")")) {
            if (level-- <= 0) {
                break;
            }
        } else if (converter.readIf("|") && level == 0) {
            String or = partList.substring(lastOrIndex, parseIndex - 1);
            parts.add(or);
            lastOrIndex = parseIndex;
        } else if (converter.currentTokenType == END) {
            throw getSyntaxError("empty query or missing ')'");
        } else {
            converter.read();
        }
    }
    String or = partList.substring(lastOrIndex, parseIndex - 1);
    parts.add(or);
    String end = partList.substring(parseIndex);
    Statement result = null;
    ArrayList<Order> orderList = null;
    QueryOptions queryOptions = null;
    for (String p : parts) {
        String q = begin + p + end;
        converter = new XPathToSQL2Converter();
        Statement stat = converter.convertToStatement(q);
        orderList = stat.orderList;
        queryOptions = stat.queryOptions;
        // reset fields that are used in the union,
        // but no longer in the individual statements
        // (can not use clear, because it is shared)
        stat.orderList = new ArrayList<Order>();
        stat.queryOptions = null;
        if (result == null) {
            result = stat;
        } else {
            UnionStatement union = new UnionStatement(result, stat);
            result = union;
        }
    }
    result.orderList = orderList;
    result.queryOptions = queryOptions;
    result.setExplain(statement.explain);
    result.setMeasure(statement.measure);
    return result;
}