org.apache.nifi.attribute.expression.language

Class Query

java.lang.Object

org.apache.nifi.attribute.expression.language.Query

public class Query
extends Object

Class used for creating and evaluating NiFi Expression Language. Once a Query has been created, it may be evaluated using the evaluate methods exactly once.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Query.Range

Field Summary

Fields

Modifier and Type	Field and Description
private EvaluatorState	context
private AtomicBoolean	evaluated
private Evaluator<?>	evaluator
private String	query
private org.antlr.runtime.tree.Tree	tree

Constructor Summary

Constructors

Modifier	Constructor and Description
private	Query(String query, org.antlr.runtime.tree.Tree tree, Evaluator<?> evaluator)

Method Summary

Modifier and Type	Method and Description
private static void	addLiteralsAndParameters(ParameterParser parser, String input, List<Expression> expressions)
static Query	compile(String query)
(package private) QueryResult<?>	evaluate(EvaluationContext evaluationContext)
(package private) static String	evaluateExpression(org.antlr.runtime.tree.Tree tree, Evaluator<?> rootEvaluator, String queryText, EvaluationContext evaluationContext, AttributeValueDecorator decorator)
(package private) static String	evaluateExpressions(String rawValue, Map<String,String> expressionMap, AttributeValueDecorator decorator, Map<String,String> stateVariables, ParameterLookup parameterLookup)
(package private) static String	evaluateExpressions(String rawValue, Map<String,String> valueLookup, AttributeValueDecorator decorator, ParameterLookup parameterLookup)
(package private) static String	evaluateExpressions(String rawValue, Map<String,String> valueLookup, ParameterLookup parameterLookup)
static List<Query.Range>	extractEscapedRanges(String value)
static List<Query.Range>	extractExpressionRanges(String value)
private static List<Query.Range>	extractExpressionRanges(String value, boolean extractEscapeSequences)
static List<String>	extractExpressions(String value)
static List<AttributeExpression.ResultType>	extractResultTypes(String value)
(package private) static int	findEndQuoteChar(String value, int quoteStart)
static Query	fromTree(org.antlr.runtime.tree.Tree tree, String text)
AttributeExpression.ResultType	getResultType()
static AttributeExpression.ResultType	getResultType(String value)
(package private) org.antlr.runtime.tree.Tree	getTree()
static boolean	isValidExpression(String value)
static PreparedQuery	prepare(String query)
private static PreparedQuery	prepare(String rawQuery, boolean escapeParameterReferences)
static PreparedQuery	prepareWithParametersPreEvaluated(String query)
String	toString()
static String	unescape(String value) Un-escapes ${...} patterns that were escaped
private static String	unescapeLeadingDollarSigns(String value)
private static String	unescapeTrailingDollarSigns(String value, boolean escapeIfAllDollars)
static void	validateExpression(String value, boolean allowSurroundingCharacters)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

query

private final String query

tree

private final org.antlr.runtime.tree.Tree tree

evaluator

private final Evaluator<?> evaluator

evaluated

private final AtomicBoolean evaluated

context

private final EvaluatorState context

Constructor Detail

Query

private Query(String query,
              org.antlr.runtime.tree.Tree tree,
              Evaluator<?> evaluator)

Method Detail

isValidExpression

public static boolean isValidExpression(String value)

getResultType

public static AttributeExpression.ResultType getResultType(String value)
                                                    throws AttributeExpressionLanguageParsingException

Throws:

AttributeExpressionLanguageParsingException

extractResultTypes

public static List<AttributeExpression.ResultType> extractResultTypes(String value)
                                                               throws AttributeExpressionLanguageParsingException

Throws:

AttributeExpressionLanguageParsingException

extractExpressions

public static List<String> extractExpressions(String value)
                                       throws AttributeExpressionLanguageParsingException

Throws:

AttributeExpressionLanguageParsingException

extractExpressionRanges

public static List<Query.Range> extractExpressionRanges(String value)
                                                 throws AttributeExpressionLanguageParsingException

Throws:

AttributeExpressionLanguageParsingException

extractEscapedRanges

public static List<Query.Range> extractEscapedRanges(String value)
                                              throws AttributeExpressionLanguageParsingException

Throws:

AttributeExpressionLanguageParsingException

extractExpressionRanges

private static List<Query.Range> extractExpressionRanges(String value,
                                                         boolean extractEscapeSequences)
                                                  throws AttributeExpressionLanguageParsingException

Throws:

AttributeExpressionLanguageParsingException

validateExpression

public static void validateExpression(String value,
                                      boolean allowSurroundingCharacters)
                               throws AttributeExpressionLanguageParsingException

Parameters:

value - expression to validate

allowSurroundingCharacters - whether to allow surrounding chars

Throws:

AttributeExpressionLanguageParsingException - if problems parsing given expression

findEndQuoteChar

static int findEndQuoteChar(String value,
                            int quoteStart)

evaluateExpression

static String evaluateExpression(org.antlr.runtime.tree.Tree tree,
                                 Evaluator<?> rootEvaluator,
                                 String queryText,
                                 EvaluationContext evaluationContext,
                                 AttributeValueDecorator decorator)
                          throws ProcessException

Throws:

ProcessException

evaluateExpressions

static String evaluateExpressions(String rawValue,
                                  Map<String,String> expressionMap,
                                  AttributeValueDecorator decorator,
                                  Map<String,String> stateVariables,
                                  ParameterLookup parameterLookup)
                           throws ProcessException

Throws:

ProcessException

evaluateExpressions

static String evaluateExpressions(String rawValue,
                                  Map<String,String> valueLookup,
                                  ParameterLookup parameterLookup)
                           throws ProcessException

Throws:

ProcessException

evaluateExpressions

static String evaluateExpressions(String rawValue,
                                  Map<String,String> valueLookup,
                                  AttributeValueDecorator decorator,
                                  ParameterLookup parameterLookup)
                           throws ProcessException

Throws:

ProcessException

unescape

public static String unescape(String value)

Un-escapes ${...} patterns that were escaped

Parameters:

value - to un-escape

Returns:

un-escaped value

fromTree

public static Query fromTree(org.antlr.runtime.tree.Tree tree,
                             String text)

unescapeLeadingDollarSigns

private static String unescapeLeadingDollarSigns(String value)

unescapeTrailingDollarSigns

private static String unescapeTrailingDollarSigns(String value,
                                                  boolean escapeIfAllDollars)

prepareWithParametersPreEvaluated

public static PreparedQuery prepareWithParametersPreEvaluated(String query)
                                                       throws AttributeExpressionLanguageParsingException

Throws:

AttributeExpressionLanguageParsingException

prepare

public static PreparedQuery prepare(String query)
                             throws AttributeExpressionLanguageParsingException

Throws:

AttributeExpressionLanguageParsingException

prepare

private static PreparedQuery prepare(String rawQuery,
                                     boolean escapeParameterReferences)
                              throws AttributeExpressionLanguageParsingException

Throws:

AttributeExpressionLanguageParsingException

addLiteralsAndParameters

private static void addLiteralsAndParameters(ParameterParser parser,
                                             String input,
                                             List<Expression> expressions)

compile

public static Query compile(String query)
                     throws AttributeExpressionLanguageParsingException

Throws:

AttributeExpressionLanguageParsingException

getResultType

public AttributeExpression.ResultType getResultType()

evaluate

QueryResult<?> evaluate(EvaluationContext evaluationContext)

getTree

org.antlr.runtime.tree.Tree getTree()

toString

public String toString()

Overrides:

toString in class Object