Package io.confluent.kafka.schemaregistry.rules.cel

Class CelUtils

java.lang.Object

io.confluent.kafka.schemaregistry.rules.cel.CelUtils

public final class CelUtils
extends Object

Shared CEL helpers used by both the transform-path executor (CelExecutor) and the validation-path executor (CelValidator). All methods are stateless.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	CelUtils.CompiledRule	Compiled rule output: the runnable CelRuntime.Program plus the compile-time result-type CelKind.
static enum	CelUtils.RegexEngine	Regex engine used by the CEL matches / matches_string overloads.
static enum	CelUtils.ScriptType

Method Summary

Modifier and Type	Method	Description
static CelUtils.CompiledRule	buildCompiledRule(CelUtils.ScriptType type, String expr, Object schemaHint, List<dev.cel.common.CelVarDecl> varDecls, CelUtils.RegexEngine regexEngine)	Like buildProgram(io.confluent.kafka.schemaregistry.rules.cel.CelUtils.ScriptType, java.lang.String, java.lang.Object, java.util.List<dev.cel.common.CelVarDecl>) but exposes the compiled AST's result-type CelKind alongside the runnable program.
static dev.cel.runtime.CelRuntime.Program	buildProgram(CelUtils.ScriptType type, String expr, Object schemaHint, List<dev.cel.common.CelVarDecl> varDecls)	Build a CEL CelRuntime.Program for (type, expr, schemaHint, varDecls).
static dev.cel.runtime.CelRuntime.Program	buildProgram(CelUtils.ScriptType type, String expr, Object schemaHint, List<dev.cel.common.CelVarDecl> varDecls, CelUtils.RegexEngine regexEngine)
static dev.cel.common.types.CelType	findCelType(Object arg)	Infer the CelType for a runtime value.
static dev.cel.common.types.CelType	findCelTypeForAvroSchema(org.apache.avro.Schema schema)	Map an Avro Schema to a CelType.
static dev.cel.common.types.CelType	findCelTypeForClass(Class<?> type)	Map a Java Class to a CelType.
static Object	toCelValue(Object value)	Convert a native value to a CEL-compatible shape: IndexedRecord (covers both GenericRecord and SpecificRecord) → JDK Map (Google cel-java's runtime selects fields on Maps natively) Utf8 / GenericEnumSymbol → String Narrow numeric types (Integer, Short, Byte, Float) widened to CEL's natural widths (long / double) byte[] / ByteString → CelByteString (CEL bytes literals only compare equal to other CelByteStrings) Lists/maps recursively converted Other values (proto Messages, BigDecimal, primitives at correct width, etc.) pass through unchanged.
static Object	toCelValueForJson(Object value, com.fasterxml.jackson.databind.ObjectMapper mapper)	JSON-flavored variant of toCelValue(Object): additionally converts Jackson JsonNode and arbitrary POJOs to maps via the supplied ObjectMapper.
static Map<String,dev.cel.common.types.CelType>	toDeclTypes(Map<String,Object> args)	Build a name→CelType map by inferring each value's type.
static List<dev.cel.common.CelVarDecl>	toVarDecls(Map<String,dev.cel.common.types.CelType> args)	Convenience wrapper to construct CelVarDecl list from a name→type map, preserving insertion order.

Methods inherited from class java.lang.Object

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

Method Details

buildProgram

public static dev.cel.runtime.CelRuntime.Program buildProgram(CelUtils.ScriptType type,
 String expr,
 Object schemaHint,
 List<dev.cel.common.CelVarDecl> varDecls)
                                                       throws dev.cel.common.CelValidationException,
dev.cel.runtime.CelEvaluationException

Build a CEL CelRuntime.Program for (type, expr, schemaHint, varDecls). The compiler is configured with the standard library, our BuiltinLibrary, and any format-specific type registration; the runtime mirrors the compile-side configuration so resolved overload IDs find their bindings.

For AVRO and JSON values, callers should pre-convert native values (GenericRecord, Jackson JsonNode, etc.) to CEL-native shapes (Map / List / scalar) via toCelValue(Object) before binding. Field access (this.field, this["field"]) then works through CEL's built-in map semantics — no custom type provider is required.

Throws:

dev.cel.common.CelValidationException

dev.cel.runtime.CelEvaluationException

buildProgram

public static dev.cel.runtime.CelRuntime.Program buildProgram(CelUtils.ScriptType type,
 String expr,
 Object schemaHint,
 List<dev.cel.common.CelVarDecl> varDecls,
 CelUtils.RegexEngine regexEngine)
                                                       throws dev.cel.common.CelValidationException,
dev.cel.runtime.CelEvaluationException

Throws:

dev.cel.common.CelValidationException

dev.cel.runtime.CelEvaluationException

buildCompiledRule

public static CelUtils.CompiledRule buildCompiledRule(CelUtils.ScriptType type,
 String expr,
 Object schemaHint,
 List<dev.cel.common.CelVarDecl> varDecls,
 CelUtils.RegexEngine regexEngine)
                                               throws dev.cel.common.CelValidationException,
dev.cel.runtime.CelEvaluationException

Like buildProgram(io.confluent.kafka.schemaregistry.rules.cel.CelUtils.ScriptType, java.lang.String, java.lang.Object, java.util.List<dev.cel.common.CelVarDecl>) but exposes the compiled AST's result-type CelKind alongside the runnable program. Lets callers (notably CelValidator) reject rules whose result type doesn't fit their contract, at compile time rather than first eval.

Throws:

dev.cel.common.CelValidationException

dev.cel.runtime.CelEvaluationException

toVarDecls

public static List<dev.cel.common.CelVarDecl> toVarDecls(Map<String,dev.cel.common.types.CelType> args)

Convenience wrapper to construct CelVarDecl list from a name→type map, preserving insertion order.

toDeclTypes

public static Map<String,dev.cel.common.types.CelType> toDeclTypes(Map<String,Object> args)

Build a name→CelType map by inferring each value's type. Insertion order is preserved (uses LinkedHashMap) so generated declarations match argument binding order.

findCelType

public static dev.cel.common.types.CelType findCelType(Object arg)

Infer the CelType for a runtime value. Used to declare this (and other variables) in the compiler so the type-checker can validate field access.

findCelTypeForAvroSchema

public static dev.cel.common.types.CelType findCelTypeForAvroSchema(org.apache.avro.Schema schema)

Map an Avro Schema to a CelType.

• Primitives map to their natural CEL counterpart (BOOLEAN→BOOL, INT/LONG→INT, FLOAT/DOUBLE→DOUBLE, STRING/ENUM→STRING, BYTES/FIXED→BYTES, NULL→NULL_TYPE).
• RECORD → StructTypeReference so the AvroCelTypeProvider registered by buildProgram(io.confluent.kafka.schemaregistry.rules.cel.CelUtils.ScriptType, java.lang.String, java.lang.Object, java.util.List<dev.cel.common.CelVarDecl>) resolves field types at type-check time. Runtime values still flow through as JDK maps (via toCelValue(java.lang.Object)); the struct declaration is purely for compile-side field validation. If the provider can't represent the record cleanly, buildProgram(io.confluent.kafka.schemaregistry.rules.cel.CelUtils.ScriptType, java.lang.String, java.lang.Object, java.util.List<dev.cel.common.CelVarDecl>) retries with this downgraded to map<string, dyn>.
• ARRAY → list<dyn>; MAP → map<string, dyn>.
• UNION: nullable [null, X] unwraps to X; multi-branch unions (and any unrecognized type) fall back to dyn.

findCelTypeForClass

public static dev.cel.common.types.CelType findCelTypeForClass(Class<?> type)

Map a Java Class to a CelType. Used when the value isn't a GenericContainer or proto Message (i.e., a JSON-derived primitive value or a primitive Avro/Proto field bound to this).

toCelValue

public static Object toCelValue(Object value)

Convert a native value to a CEL-compatible shape:

• IndexedRecord (covers both GenericRecord and SpecificRecord) → JDK Map (Google cel-java's runtime selects fields on Maps natively)
• Utf8 / GenericEnumSymbol → String
• Narrow numeric types (Integer, Short, Byte, Float) widened to CEL's natural widths (long / double)
• byte[] / ByteString → CelByteString (CEL bytes literals only compare equal to other CelByteStrings)
• Lists/maps recursively converted

Other values (proto Messages, BigDecimal, primitives at correct width, etc.) pass through unchanged.

toCelValueForJson

public static Object toCelValueForJson(Object value,
 com.fasterxml.jackson.databind.ObjectMapper mapper)

JSON-flavored variant of toCelValue(Object): additionally converts Jackson JsonNode and arbitrary POJOs to maps via the supplied ObjectMapper. Used on the JSON validation/transform path where the value passed in might be a bean — we materialize beans as maps so the CEL runtime's native map field-access path applies.

Primitives, strings, byte buffers, proto Messages, Avro GenericRecord and Utf8 delegate to toCelValue(Object).