MetadataEntity (CDAP API 6.5.0 API)

java.lang.Object
- io.cdap.cdap.api.metadata.MetadataEntity

All Implemented Interfaces:

Iterable<MetadataEntity.KeyValue>
```
@Beta
public class MetadataEntity
extends Object
implements Iterable<MetadataEntity.KeyValue>
```
Represents either a CDAP entity or a custom entity in metadata APIs. A MetadataEntity is an ordered sequence of key/value pairs constructed using MetadataEntity.Builder. Keys are case insensitive.

Example usage: Creating a MetadataEntity for Dataset
```
   MetadataEntity.builder().append(MetadataEntity.NAMESPACE, "ns")
     .appendAsType(MetadataEntity.DATASET, "myDataset").build();
 
```
Creating a MetadataEntity for a custom entity: a field in a dataset:
```
   MetadataEntity.builder().append(MetadataEntity.NAMESPACE, "ns").append(MetadataEntity.DATASET, "ds")
    .appendAsType("field", "myField").build();
 
```
Every metadata entity has a type. If a type is not specifically specified by calling MetadataEntity.Builder.appendAsType(String, String) the last key in the hierarchy will be the type by default. In some cases, the type is a key in middle and MetadataEntity.Builder.appendAsType(String, String) helps in representing these. An example of this is ApplicationId which ends with "version" although the type is "application".
```
   MetadataEntity.builder().append(MetadataEntity.NAMESPACE, "ns")
     .appendAsType(MetadataEntity.APPLICATION, "myApp").append(MetadataEntity.VERSION, "1").build();
 
```
This class also provide helper methods for creating MetadataEntity for:
- CDAP Namespace: ofNamespace(String)
- CDAP Dataset: ofDataset(String, String) and ofDataset(String). The ofDataset(String) lacks namespace information and does not represent complete information to represent a Dataset. It is provided to conveniently refer to a Dataset in current namespace and should only be used when it is known that the handler can fill in the namespace information.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class MetadataEntity.Builder
Builder for MetadataEntity

static class MetadataEntity.KeyValue
MetadataEntity key-value.

Nested Classes
Modifier and Type	Class and Description
`static class`	`MetadataEntity.Builder` Builder for `MetadataEntity`
`static class`	`MetadataEntity.KeyValue` `MetadataEntity` key-value.

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`APPLICATION`
`static String`	`ARTIFACT`
`static String`	`DATASET`
`static String`	`NAMESPACE`
`static String`	`PLUGIN`
`static String`	`PROGRAM`
`static String`	`PROGRAM_RUN`
`static String`	`SCHEDULE`
`static String`	`TYPE`
`static String`	`VERSION`

Constructor Summary

Constructors
Constructor and Description

MetadataEntity(MetadataEntity metadataEntity)

Constructors
Constructor and Description
`MetadataEntity(MetadataEntity metadataEntity)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static MetadataEntity.Builder`	`builder()`
`static MetadataEntity.Builder`	`builder(MetadataEntity metadataEntity)`
`boolean`	`containsKey(String key)`
`boolean`	`equals(Object o)`
`String`	`getDescription()`
`Iterable<String>`	`getKeys()`
`String`	`getType()`
`String`	`getValue(String key)`
`int`	`hashCode()`
`List<MetadataEntity.KeyValue>`	`head(String splitKey)` Returns a List of `MetadataEntity.KeyValue` till the given splitKey (inclusive)
`Iterator<MetadataEntity.KeyValue>`	`iterator()`
`static MetadataEntity`	`ofDataset(String datasetName)` Creates a `MetadataEntity` representing the given datasetName.
`static MetadataEntity`	`ofDataset(String namespace, String datasetName)` Creates a `MetadataEntity` representing the given datasetName in the specified namespace.
`static MetadataEntity`	`ofNamespace(String namespace)` Creates a `MetadataEntity` representing the given namespace.
`String`	`toString()`

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

Methods inherited from interface java.lang.Iterable
forEach, spliterator

- Field Detail
  - NAMESPACE
```
public static final String NAMESPACE
```
    See Also:
    
    Constant Field Values
  - APPLICATION
```
public static final String APPLICATION
```
    See Also:
    
    Constant Field Values
  - ARTIFACT
```
public static final String ARTIFACT
```
    See Also:
    
    Constant Field Values
  - VERSION
```
public static final String VERSION
```
    See Also:
    
    Constant Field Values
  - DATASET
```
public static final String DATASET
```
    See Also:
    
    Constant Field Values
  - TYPE
```
public static final String TYPE
```
    See Also:
    
    Constant Field Values
  - PROGRAM
```
public static final String PROGRAM
```
    See Also:
    
    Constant Field Values
  - SCHEDULE
```
public static final String SCHEDULE
```
    See Also:
    
    Constant Field Values
  - PROGRAM_RUN
```
public static final String PROGRAM_RUN
```
    See Also:
    
    Constant Field Values
  - PLUGIN
```
public static final String PLUGIN
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - MetadataEntity
```
public MetadataEntity(MetadataEntity metadataEntity)
```
- Method Detail
  - ofNamespace
```
public static MetadataEntity ofNamespace(String namespace)
```
    Creates a MetadataEntity representing the given namespace.
    
    Parameters:
    
    namespace - the name of the namespace
    
    Returns:
    
    MetadataEntity representing the namespace name
    
    Throws:
    
    IllegalArgumentException - if the key is a CDAP entity and the MetadataEntity is not correct to represent the CDAP entity
  - ofDataset
```
public static MetadataEntity ofDataset(String datasetName)
```
    Creates a MetadataEntity representing the given datasetName. To create a MetadataEntity for a dataset in a specified namespace please use ofDataset(String, String).
    
    Parameters:
    
    datasetName - the name of the dataset
    
    Returns:
    
    MetadataEntity representing the dataset name
  - ofDataset
```
public static MetadataEntity ofDataset(String namespace,
                                       String datasetName)
```
    Creates a MetadataEntity representing the given datasetName in the specified namespace.
    
    Parameters:
    
    namespace - the name of the namespace
    
    datasetName - the name of the dataset
    
    Returns:
    
    MetadataEntity representing the dataset name
    
    Throws:
    
    IllegalArgumentException - if the key is a CDAP entity and the MetadataEntity is not correct to represent the CDAP entity
  - head
```
public List<MetadataEntity.KeyValue> head(String splitKey)
```
    Returns a List of MetadataEntity.KeyValue till the given splitKey (inclusive)
    
    Parameters:
    
    splitKey - the splitKey (inclusive)
    
    Returns:
    
    List of MetadataEntity.KeyValue
  - getDescription
```
public String getDescription()
```
    Returns:
    
    a String which describes the MetadataEntity for a user in plain english. If the MetadataEntity represents a known CDAP entity then the description is worded to show relations in the hierarchy.
  - getType
```
public String getType()
```
    Returns:
    
    the type of the MetadataEntity
  - getValue
```
@Nullable
public String getValue(String key)
```
    Returns:
    
    the value for the given key; if the key does not exists returns null;
  - containsKey
```
public boolean containsKey(String key)
```
    Returns:
    
    true if there is an entry for the key in the MetadataEntity else false
  - getKeys
```
public Iterable<String> getKeys()
```
    Returns:
    
    all the keys in the MetadataEntity
  - builder
```
public static MetadataEntity.Builder builder()
```
  - builder
```
public static MetadataEntity.Builder builder(MetadataEntity metadataEntity)
```
  - iterator
```
public Iterator<MetadataEntity.KeyValue> iterator()
```
    Specified by:
    
    iterator in interface Iterable<MetadataEntity.KeyValue>
    
    Returns:
    
    A List of MetadataEntity.KeyValue representing the metadata entity
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - equals
```
public boolean equals(Object o)
```
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object

Class MetadataEntity

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.lang.Iterable

Field Detail

NAMESPACE

APPLICATION

ARTIFACT

VERSION

DATASET

TYPE

PROGRAM

SCHEDULE

PROGRAM_RUN

PLUGIN

Constructor Detail

MetadataEntity

Method Detail

ofNamespace

ofDataset

ofDataset

head

getDescription

getType

getValue

containsKey

getKeys

builder

builder

iterator

toString

equals

hashCode