DefaultEnumMapper (Ignite 2.18.0)

java.lang.Object
- org.apache.ignite.plugin.extensions.communication.mappers.DefaultEnumMapper

```
public final class DefaultEnumMapper
extends Object
```
A default enum mapper that uses enum ordinal values to perform serialization and deserialization.
This mapper encodes an enum constant into a byte by taking its Enum.ordinal(), and decodes a byte value back into the corresponding enum constant using array indexing. The encoding returns -1 for null inputs, and decoding returns null for negative codes. If a provided code is out of range (greater than or equal to the number of enum constants), an IllegalArgumentException is thrown.

This class assumes that:
- Enums have no more than 127 constants (to fit in a positive byte).
- The order of enum constants (i.e., their ordinals) is stable and not subject to change.
Example usage:
```
 public enum Color {
     RED, GREEN, BLUE;
 }

 Color[] values = Color.values();
 byte code = DefaultEnumMapper.INSTANCE.encode(Color.RED); // Returns 0
 Color color = DefaultEnumMapper.INSTANCE.decode(values, code); // Returns Color.RED
 
```
Note: This class is thread-safe and uses a singleton pattern. Use INSTANCE to access the shared instance.
See Also:

Enum.ordinal()

Field Summary

Fields
Modifier and Type Field Description

static DefaultEnumMapper INSTANCE

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`<T extends Enum<T>> T`	`decode(T[] vals, byte enumCode)`	Decodes a `byte` code into the corresponding enum constant.
`<T extends Enum<T>> byte`	`encode(T enumVal)`	Encodes the given enum value into a `byte` using its ordinal.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - INSTANCE
```
public static final DefaultEnumMapper INSTANCE
```
- Method Detail
  - encode
```
public <T extends Enum<T>> byte encode(T enumVal)
```
    Encodes the given enum value into a byte using its ordinal.
    
    Type Parameters:
    
    T - The enum type.
    
    Parameters:
    
    enumVal - The enum value to encode; may be null.
    
    Returns:
    
    The byte representation of the enum value (non-negative) or -1 if the value is null.
  - decode
```
public <T extends Enum<T>> T decode(T[] vals,
                                    byte enumCode)
```
    Decodes a byte code into the corresponding enum constant.
    
    Type Parameters:
    
    T - The enum type.
    
    Parameters:
    
    vals - Array of all possible values of the enum type. Must not be null.
    
    enumCode - The byte representation of the enum value.
    
    Returns:
    
    The corresponding enum constant, or null if enumCode is negative.
    
    Throws:
    
    IllegalArgumentException - if enumCode is out of range (i.e., greater than or equal to the length of vals array).