Examples with ExpressionCompiler org.apache.nifi.attribute.expression.language.compile.ExpressionCompiler used on opensource projects

Example 1 with ExpressionCompiler

use of org.apache.nifi.attribute.expression.language.compile.ExpressionCompiler in project nifi by apache.

the class Query method prepare.

public static PreparedQuery prepare(final String query) throws AttributeExpressionLanguageParsingException {
    if (query == null) {
        return new EmptyPreparedQuery(null);
    }
    final List<Range> ranges = extractExpressionRanges(query);
    if (ranges.isEmpty()) {
        return new EmptyPreparedQuery(query.replace("$$", "$"));
    }
    final ExpressionCompiler compiler = new ExpressionCompiler();
    try {
        final List<Expression> expressions = new ArrayList<>();
        int lastIndex = 0;
        for (final Range range : ranges) {
            if (range.getStart() > lastIndex) {
                final String substring = query.substring(lastIndex, range.getStart()).replace("$$", "$");
                expressions.add(new StringLiteralExpression(substring));
                lastIndex = range.getEnd() + 1;
            }
            final String treeText = query.substring(range.getStart(), range.getEnd() + 1).replace("$$", "$");
            final CompiledExpression compiledExpression = compiler.compile(treeText);
            expressions.add(compiledExpression);
            lastIndex = range.getEnd() + 1;
        }
        final Range lastRange = ranges.get(ranges.size() - 1);
        if (lastRange.getEnd() + 1 < query.length()) {
            final String treeText = query.substring(lastRange.getEnd() + 1).replace("$$", "$");
            expressions.add(new StringLiteralExpression(treeText));
        }
        return new StandardPreparedQuery(expressions);
    } catch (final AttributeExpressionLanguageParsingException e) {
        return new InvalidPreparedQuery(query, e.getMessage());
    }
}

Example 2 with ExpressionCompiler

use of org.apache.nifi.attribute.expression.language.compile.ExpressionCompiler in project nifi by apache.

the class Query method compile.

public static Query compile(final String query) throws AttributeExpressionLanguageParsingException {
    try {
        final ExpressionCompiler compiler = new ExpressionCompiler();
        final CompiledExpression compiledExpression = compiler.compile(query);
        return new Query(compiledExpression.getExpression(), compiledExpression.getTree(), compiledExpression.getRootEvaluator());
    } catch (final AttributeExpressionLanguageParsingException e) {
        throw e;
    } catch (final Exception e) {
        throw new AttributeExpressionLanguageParsingException(e);
    }
}