AtomicCounterExtension (AWS Java SDK :: DynamoDB :: Enhanced Client 2.23.0 API)

java.lang.Object
- software.amazon.awssdk.enhanced.dynamodb.extensions.AtomicCounterExtension

All Implemented Interfaces:

DynamoDbEnhancedClientExtension
```
public final class AtomicCounterExtension
extends Object
implements DynamoDbEnhancedClientExtension
```
This extension enables atomic counter attributes to be changed in DynamoDb by creating instructions for modifying an existing value or setting a start value. The extension is loaded by default when you instantiate a DynamoDbEnhancedClient and only needs to be added to the client if you are adding custom extensions to the client.
To utilize atomic counters, first create a field in your model that will be used to store the counter. This class field should of type Long and you need to tag it as an atomic counter:
- If you are using the BeanTableSchema, you should annotate with DynamoDbAtomicCounter
- If you are using the StaticTableSchema, use the StaticAttributeTags.atomicCounter() static attribute tag.
Every time a new update of the record is successfully written to the database, the counter will be updated automatically. By default, the counter starts at 0 and increments by 1 for each update. The tags provide the capability of adjusting the counter start and increment/decrement values such as described in DynamoDbAtomicCounter.
Example 1: Using a bean based table schema
```
 {@code
```

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class AtomicCounterExtension.Builder

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`WriteModification`	`beforeWrite(DynamoDbExtensionContext.BeforeWrite context)`	This hook is called just before an operation is going to write data to the database.
`static AtomicCounterExtension.Builder`	`builder()`

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

Methods inherited from interface software.amazon.awssdk.enhanced.dynamodb.DynamoDbEnhancedClientExtension
afterRead

- Method Detail
  - builder
```
public static AtomicCounterExtension.Builder builder()
```
  - beforeWrite
```
public WriteModification beforeWrite(DynamoDbExtensionContext.BeforeWrite context)
```
    Description copied from interface: DynamoDbEnhancedClientExtension
    
    This hook is called just before an operation is going to write data to the database. The extension that implements this method can choose to transform the item itself, or add a condition to the write operation or both.
    
    Specified by:
    
    beforeWrite in interface DynamoDbEnhancedClientExtension
    
    Parameters:
    
    context - The DynamoDbExtensionContext.BeforeWrite context containing the state of the execution.
    
    Returns:
    
    WriteModification contains an update expression representing the counters.