Examples with RootPath org.apache.nifi.record.path.paths.RootPath used on opensource projects

Example 1 with RootPath

use of org.apache.nifi.record.path.paths.RootPath in project nifi by apache.

the class RecordPath method compile.

/**
 * Compiles a RecordPath from the given text
 *
 * @param path the textual representation of the RecordPath
 * @return the compiled RecordPath
 * @throws RecordPathException if the given text is not a valid RecordPath
 */
public static RecordPath compile(final String path) throws RecordPathException {
    try {
        final CharStream input = new ANTLRStringStream(path);
        final RecordPathLexer lexer = new RecordPathLexer(input);
        final CommonTokenStream lexerTokenStream = new CommonTokenStream(lexer);
        final RecordPathParser parser = new RecordPathParser(lexerTokenStream);
        final Tree tree = (Tree) parser.pathExpression().getTree();
        // We look at the first child, because 'tree' is a PATH_EXPRESSION and we really
        // want the underlying PATH token.
        final Tree firstChild = tree.getChild(0);
        final int childType = firstChild.getType();
        final boolean absolute;
        final RecordPathSegment rootPath;
        if (childType == PATH || childType == CHILD_REFERENCE) {
            rootPath = new RootPath();
            absolute = true;
        } else {
            rootPath = null;
            absolute = false;
        }
        return RecordPathCompiler.compile(firstChild, rootPath, absolute);
    } catch (final RecordPathException e) {
        throw e;
    } catch (final Exception e) {
        throw new RecordPathException(e);
    }
}