Persistent (JDO API 3.1)

```
@Target(value={FIELD,METHOD})
 @Retention(value=RUNTIME)
public @interface Persistent
```
Annotation for defining the persistence of a member. This corresponds to the xml elements "field" and "property".

Since:

2.1

Version:

2.1

Optional Element Summary

Optional Elements
Modifier and Type	Optional Element and Description
`String`	`cacheable` Whether this field/property is cacheable in a Level2 cache.
`String`	`column` Column name where the values are stored for this member.
`Column[]`	`columns` Column definition(s) for this member.
`String`	`customValueStrategy` Custom value strategy to use to generate the value for this field or property (if any).
`String`	`defaultFetchGroup` Whether this member is in the default fetch group.
`String`	`dependent` Whether related object(s) of this member are dependent and so deleted when this object is deleted.
`String`	`dependentElement` Whether the elements of this member are dependent.
`String`	`dependentKey` Whether the keys of this member are dependent.
`String`	`dependentValue` Whether the values of this member are dependent.
`String`	`embedded` Whether this member is embedded.
`String`	`embeddedElement` Whether the elements of this member are embedded.
`String`	`embeddedKey` Whether the keys of this member are embedded.
`String`	`embeddedValue` Whether the values of this member are embedded.
`Extension[]`	`extensions` Vendor extensions for this member.
`String`	`loadFetchGroup` Name of the fetch-group to use when this member is loaded due to being referenced when not already loaded.
`String`	`mappedBy` Name of the related member in the other class where this value is mapped (bidirectional relationship).
`String`	`name` Name of the member when this is embedded in another object.
`String`	`nullIndicatorColumn` Null indicator column for this member.
`NullValue`	`nullValue` Behavior when this member contains a null value.
`PersistenceModifier`	`persistenceModifier` Modifier for this field.
`String`	`primaryKey` Whether this member is part of the primary key for application identity.
`int`	`recursionDepth` Recursion depth for this member.
`String`	`sequence` Name of the sequence to use with particular value strategies.
`String`	`serialized` Whether this member is serialized into a single column.
`String`	`serializedElement` Whether the elements of this member are serialized.
`String`	`serializedKey` Whether the keys of this member are serialized.
`String`	`serializedValue` Whether the values of this member are serialized.
`String`	`table` Table to use for persisting this member.
`Class[]`	`types` Types of the member.
`IdGeneratorStrategy`	`valueStrategy` Value strategy to use to generate the value for this field or property (if any).

- Element Detail
  - persistenceModifier
```
public abstract PersistenceModifier persistenceModifier
```
    Modifier for this field. This is normally not specified, and the defaults are used, or the @Transactional or @NotPersistent annotation is specified directly on the member. One possible use for specifying persistenceModifier is for embedded instances in which a member is not persistent but in the non-embedded instances the member is persistent. Note that it is not portable to specify a member to be not persistent in the non-embedded case and persistent in the embedded usage.
    
    Returns:
    
    the persistence modifier
    
    Default:
    
    javax.jdo.annotations.PersistenceModifier.UNSPECIFIED
- - table
```
public abstract String table
```
    Table to use for persisting this member.
    
    Returns:
    
    the table to use for persisting this member
    
    Default:
    
    ""
- - defaultFetchGroup
```
public abstract String defaultFetchGroup
```
    Whether this member is in the default fetch group.
    
    Returns:
    
    whether this member is in the default fetch group
    
    Default:
    
    ""
- - nullValue
```
public abstract NullValue nullValue
```
    Behavior when this member contains a null value.
    
    Returns:
    
    the behavior when this member contains a null value
    
    Default:
    
    javax.jdo.annotations.NullValue.NONE
- - embedded
```
public abstract String embedded
```
    Whether this member is embedded.
    
    Returns:
    
    whether this member is embedded
    
    Default:
    
    ""
- - embeddedElement
```
public abstract String embeddedElement
```
    Whether the elements of this member are embedded.
    
    Returns:
    
    whether the elements of this member are embedded
    
    Default:
    
    ""
- - embeddedKey
```
public abstract String embeddedKey
```
    Whether the keys of this member are embedded.
    
    Returns:
    
    whether the keys of this member are embedded
    
    Default:
    
    ""
- - embeddedValue
```
public abstract String embeddedValue
```
    Whether the values of this member are embedded.
    
    Returns:
    
    whether the values of this member are embedded
    
    Default:
    
    ""
- - serialized
```
public abstract String serialized
```
    Whether this member is serialized into a single column.
    
    Returns:
    
    whether this member is serialized into a single column
    
    Default:
    
    ""
- - serializedElement
```
public abstract String serializedElement
```
    Whether the elements of this member are serialized.
    
    Returns:
    
    whether the elements of this member are serialized
    
    Default:
    
    ""
- - serializedKey
```
public abstract String serializedKey
```
    Whether the keys of this member are serialized.
    
    Returns:
    
    whether the keys of this member are serialized
    
    Default:
    
    ""
- - serializedValue
```
public abstract String serializedValue
```
    Whether the values of this member are serialized.
    
    Returns:
    
    whether the values of this member are serialized
    
    Default:
    
    ""
- - dependent
```
public abstract String dependent
```
    Whether related object(s) of this member are dependent and so deleted when this object is deleted.
    
    Returns:
    
    whether the related object(s) of this member are dependent
    
    Default:
    
    ""
- - dependentElement
```
public abstract String dependentElement
```
    Whether the elements of this member are dependent.
    
    Returns:
    
    whether the elements of this member are dependent
    
    Default:
    
    ""
- - dependentKey
```
public abstract String dependentKey
```
    Whether the keys of this member are dependent.
    
    Returns:
    
    whether the keys of this member are dependent
    
    Default:
    
    ""
- - dependentValue
```
public abstract String dependentValue
```
    Whether the values of this member are dependent.
    
    Returns:
    
    whether the values of this member are dependent
    
    Default:
    
    ""
- - primaryKey
```
public abstract String primaryKey
```
    Whether this member is part of the primary key for application identity. This is equivalent to specifying @PrimaryKey as a separate annotation on the member.
    
    Returns:
    
    whether this member is part of the primary key
    
    Default:
    
    ""
- - valueStrategy
```
public abstract IdGeneratorStrategy valueStrategy
```
    Value strategy to use to generate the value for this field or property (if any).
    
    Returns:
    
    the generated value strategy
    
    Default:
    
    javax.jdo.annotations.IdGeneratorStrategy.UNSPECIFIED
- - customValueStrategy
```
public abstract String customValueStrategy
```
    Custom value strategy to use to generate the value for this field or property (if any). If customValueStrategy is non-empty, then valueStrategy must be UNSPECIFIED.
    
    Returns:
    
    the custom value strategy
    
    Default:
    
    ""
- - sequence
```
public abstract String sequence
```
    Name of the sequence to use with particular value strategies.
    
    Returns:
    
    the name of the sequence
    
    Default:
    
    ""
- - loadFetchGroup
```
public abstract String loadFetchGroup
```
    Name of the fetch-group to use when this member is loaded due to being referenced when not already loaded.
    
    Returns:
    
    the name of the load fetch group
    
    Default:
    
    ""
- - types
```
public abstract Class[] types
```
    Types of the member. Used when the declared member type is a supertype of the actual type that is stored in the member. For example, the declared member type might be an interface type that must contain an object of a concrete type when used for persistence.
    
    Returns:
    
    the types
    
    Default:
    
    {}
- - mappedBy
```
public abstract String mappedBy
```
    Name of the related member in the other class where this value is mapped (bidirectional relationship).
    
    Returns:
    
    the related member in the other class
    
    Default:
    
    ""
- - columns
```
public abstract Column[] columns
```
    Column definition(s) for this member. Used for mapping multiple columns to the same member, for example relationships with multiple column foreign keys.
    
    Returns:
    
    the columns for this member
    
    Default:
    
    {}
- - column
```
public abstract String column
```
    Column name where the values are stored for this member.
    
    Returns:
    
    the name of the column
    
    Default:
    
    ""
- - nullIndicatorColumn
```
public abstract String nullIndicatorColumn
```
    Null indicator column for this member. Used for nested embedded fields or properties to indicate whether the embedded instance should have a null value.
    
    Returns:
    
    the null indicator column
    
    Default:
    
    ""
- - name
```
public abstract String name
```
    Name of the member when this is embedded in another object. The fully-qualified member name is used. For example, "line.point1.x" refers to the member x in class Point that is embedded as member point1 in class Line that is embedded in a member called line.
    
    Returns:
    
    the name of the member
    
    Default:
    
    ""
- - recursionDepth
```
public abstract int recursionDepth
```
    Recursion depth for this member. Used only when the annotation is used within the definition of a FetchGroup.
    
    Returns:
    
    the recursion depth
    
    Default:
    
    1
- - cacheable
```
public abstract String cacheable
```
    Whether this field/property is cacheable in a Level2 cache.
    
    Since:
    
    2.2
    
    Default:
    
    "true"
- - extensions
```
public abstract Extension[] extensions
```
    Vendor extensions for this member.
    
    Returns:
    
    the vendor extensions
    
    Default:
    
    {}

Annotation Type Persistent

Optional Element Summary

Element Detail

persistenceModifier

table

defaultFetchGroup

nullValue

embedded

embeddedElement

embeddedKey

embeddedValue

serialized

serializedElement

serializedKey

serializedValue

dependent

dependentElement

dependentKey

dependentValue

primaryKey

valueStrategy

customValueStrategy

sequence

loadFetchGroup

types

mappedBy

columns

column

nullIndicatorColumn

name

recursionDepth

cacheable

extensions