com.amazonaws.services.dynamodbv2.datamodeling

Annotation Type DynamoDBDelimited

@Retention(value=RUNTIME)
 @Target(value={TYPE,FIELD,METHOD,ANNOTATION_TYPE})
public @interface DynamoDBDelimited

Annotation to convert an object into a single delimited String attribute.

 @DynamoDBDelimited(
     attributeNames={"areaCode","exchange","subscriber"},
     delimiter='-'
 )
 public PhoneNumber getPhoneNumber()
 

Where,

 public class PhoneNumber {
     private String areaCode;
     private String exchange;
     private String subscriber;

     public String getAreaCode() { return areaCode; }
     public void setAreaCode(String areaCode) { this.areaCode = areaCode; }

     public String getExchange() { return exchange; }
     public void setExchange(String exchange) { this.exchange = exchange; }

     public String getSubscriber() { return subscriber; }
     public void setSubscriber(String subscriber) { this.subscriber = subscriber; }
 }
 

Would write,

• PhoneNumber("206","266","1000") = "206-266-1000"
• PhoneNumber("206",null,"1000") = "206--1000"
• PhoneNumber("206",null,null) = "206--"
• PhoneNumber(null,"266","1000") = "-266-1000"
• PhoneNumber(null,"266",null) = "-266-"
• PhoneNumber(null,null,"1000") = "--1000"
• PhoneNumber(null,null,null) = null
• null = null

Conversely, reading not fully formatted values from DynamoDB given,

• "" = empty string not allowed by DDB but would produce empty object
• "--" = PhoneNumber(null,null,null)
• "-----" = PhoneNumber(null,null,null)
• "206" = PhoneNumber("206",null,null)
• "206-266" = PhoneNumber("206","266",null)
• "206-266-1000-1234-5678" = PhoneNumber("206","266","1000")

The converter does not protect against values which may also contain the delimiter. If more advanced conversion is required, consider implementing, a custom DynamoDBTypeConverter.

New delimited values may always be appended to the string, however, there are some risks in distributed systems where, if one system has updated delimiting instructions and begins to persist new values, other systems, which also persist that same data, would effectively truncate it back to the original format.

Auto-generated annotations are not supported on field/property.

TYpe-converted annotations, annotated by DynamoDBTypeConverted, where the output type is String are supported.

May be used as a meta-annotation.

Required Element Summary

Required Elements

Modifier and Type	Required Element and Description
String[]	attributeNames The ordered list of attribute/field names.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
char	delimiter The delimiter for separating attribute values; default is |.

Element Detail

attributeNames

public abstract String[] attributeNames

The ordered list of attribute/field names.

delimiter

public abstract char delimiter

The delimiter for separating attribute values; default is |.

Default:

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