Implementation:Apache Shardingsphere PreciseHintShadowValue DTO

Knowledge Sources	Apache_Shardingsphere
Domains	Shadow_Testing, SPI
Last Updated	2026-02-10 00:00 GMT

Overview

Immutable value object carrying hint shadow context for hint-based shadow algorithm evaluation.

Description

PreciseHintShadowValue<T> is a generic final class that bundles the context needed by HintShadowAlgorithm implementations: the logical table name, the shadow operation type, and the hint value extracted from SQL annotations. Uses Lombok @RequiredArgsConstructor and @Getter.

Usage

This DTO is constructed by the shadow routing engine and passed to HintShadowAlgorithm.isShadow() during hint-based shadow routing evaluation.

Code Reference

Source Location

• Repository: Apache_Shardingsphere
• File: features/shadow/api/src/main/java/org/apache/shardingsphere/shadow/spi/hint/PreciseHintShadowValue.java
• Lines: 1-39

Signature

@RequiredArgsConstructor
@Getter
public final class PreciseHintShadowValue<T> implements ShadowValue {

    private final String tableName;

    private final ShadowOperationType shadowOperationType;

    private final T value;
}

Import

import org.apache.shardingsphere.shadow.spi.hint.PreciseHintShadowValue;

I/O Contract

Inputs

Name	Type	Required	Description
tableName	String	Yes	Logical table name
shadowOperationType	ShadowOperationType	Yes	SQL operation type
value	T	Yes	Hint value from SQL annotation

Outputs

Name	Type	Description
getTableName()	String	Logical table name
getShadowOperationType()	ShadowOperationType	SQL operation type
getValue()	T	Hint value

Usage Examples

import org.apache.shardingsphere.shadow.spi.hint.PreciseHintShadowValue;
import org.apache.shardingsphere.shadow.spi.ShadowOperationType;

// Construct a hint shadow value
PreciseHintShadowValue<String> hintValue = new PreciseHintShadowValue<>(
    "t_order", ShadowOperationType.HINT_MATCH, "true");

// Access fields
String table = hintValue.getTableName();                      // "t_order"
ShadowOperationType opType = hintValue.getShadowOperationType(); // HINT_MATCH
String hint = hintValue.getValue();                           // "true"

Related Pages

• Principle:Apache_Shardingsphere_Hint_Based_Routing