org.apache.oodt.cas.pge.metadata

Class PgeMetadata

java.lang.Object

org.apache.oodt.cas.pge.metadata.PgeMetadata

public class PgeMetadata
extends Object

A wrapper class to act as a facade interface to all the different Metadata sources given to a PGE. NOTE: 2 ways to update DYNAMIC metadata: 1) Create a key link to a DYNAMIC metadata key, then change the value of the key link or 2) add metadata then mark the key as dynamic and commit it.

Author:

bfoster (Brian Foster), mattmann (Chris Mattmann)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PgeMetadata.Type

Field Summary

Fields

Modifier and Type	Field and Description
static List<PgeMetadata.Type>	DEFAULT_COMBINE_ORDER
static List<PgeMetadata.Type>	DEFAULT_QUERY_ORDER

Constructor Summary

Constructors

Constructor and Description
PgeMetadata()
PgeMetadata(Metadata staticMetadata, Metadata dynamicMetadata)
PgeMetadata(PgeMetadata pgeMetadata)

Method Summary

Modifier and Type	Method and Description
Metadata	asMetadata(PgeMetadata.Type... types) Combines STATIC, DYNAMIC, and LOCAL metadata into one metadata object.
void	commitMarkedDynamicMetadataKeys(String... keys) Use to commit marked LOCAL keys to DYNAMIC keys.
List<String>	getAllMetadata(PgeTaskMetKeys key, PgeMetadata.Type... types)
List<String>	getAllMetadata(String key, PgeMetadata.Type... types) Get metadata values for given key.
protected Set<String>	getMarkedAsDynamicMetadataKeys()
String	getMetadata(PgeTaskMetKeys key, PgeMetadata.Type... types)
String	getMetadata(String key, PgeMetadata.Type... types) Returns the first value returned by getAllMetadata(String, Type...), if it returns null then this method will also return null.
List<String>	getReferenceKeyPath(String key) Determines the path by which the given key (if it is a key link) links to the key whose value it will return.
boolean	isLink(String key) Check if the given key name is a key link.
void	linkKey(String keyLink, String key) Create a key which is a link to another key, such that if you get the metadata values for the created link it will return the current metadata values of the key it was linked to.
void	markAsDynamicMetadataKey(String... keys) Use to mark LOCAL keys which should be moved into DYNAMIC metadata when commitMarkedDynamicMetadataKeys(String...) is invoked.
void	replaceMetadata(Metadata metadata) Replace all key values with the given key values in the provided Metadata.
void	replaceMetadata(PgeMetadata pgeMetadata) Replaces or creates this PgeMetadata's metadata with given PgeMetadata's metadata.
void	replaceMetadata(PgeMetadata pgeMetadata, String group) Replaces or creates this PgeMetadata's metadata with given PgeMetadata's metadata.
void	replaceMetadata(PgeTaskMetKeys key, List<String> values)
void	replaceMetadata(PgeTaskMetKeys key, String value)
void	replaceMetadata(String key, List<String> values) Replace the given key's values with the given values.
void	replaceMetadata(String key, String value) Replace the given key's value with the given value.
String	resolveKey(String key) Find the actual key whose value will be returned for the given key.
void	unlinkKey(String keyLink) Removes a key link reference.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_COMBINE_ORDER

public static final List<PgeMetadata.Type> DEFAULT_COMBINE_ORDER

DEFAULT_QUERY_ORDER

public static final List<PgeMetadata.Type> DEFAULT_QUERY_ORDER

Constructor Detail

PgeMetadata

public PgeMetadata()

PgeMetadata

public PgeMetadata(PgeMetadata pgeMetadata)

PgeMetadata

public PgeMetadata(Metadata staticMetadata,
                   Metadata dynamicMetadata)

Method Detail

replaceMetadata

public void replaceMetadata(PgeMetadata pgeMetadata)

Replaces or creates this PgeMetadata's metadata with given PgeMetadata's metadata. Also adds in the list of given PgeMetadata's LOCAL metadata marked for promotion DYNAMIC metadata and list of key links.

Parameters:

pgeMetadata - A PgeMetadata whose metadata and key links will be added to this PgeMetadata's metadata and key links.

replaceMetadata

public void replaceMetadata(PgeMetadata pgeMetadata,
                            String group)

Replaces or creates this PgeMetadata's metadata with given PgeMetadata's metadata. The provided "group" will be used to namespace the given PgeMetadata's LOCAL metadata when add to this PgeMetadata's LOCAL metadata. It will also namespace given PgeMetadata's key links before adding then to this PgeMetadata's key links. Also add in the list of given PgeMetadata's LOCAL metadata marked for promotion DYNAMIC metadata.

Parameters:

pgeMetadata - A PgeMetadata whose metadata and key links will be added to this PgeMetadata's metadata and key links.

group - The namespace which will be used to namespace given PgeMetadata's LOCAL metadata and key links before being added to this PgeMetadata's LOCAL metadata and key links.

markAsDynamicMetadataKey

public void markAsDynamicMetadataKey(String... keys)

Use to mark LOCAL keys which should be moved into DYNAMIC metadata when commitMarkedDynamicMetadataKeys(String...) is invoked. If no args are specified then all LOCAL metadata is marked for move to DYNAMIC metadata.

Parameters:

keys - Keys to mark as to be made DYNAMIC, otherwise if no keys then all LOCAL metadata keys are mark for move to DYNAMIC.

commitMarkedDynamicMetadataKeys

public void commitMarkedDynamicMetadataKeys(String... keys)

Use to commit marked LOCAL keys to DYNAMIC keys. Specify a list of keys only if you want to limit the keys which get committed, otherwise all marked keys will be moved into DYNAMIC metadata.

Parameters:

keys - The list of marked LOCAL metadata keys which should be moved into DYNAMIC metadata. If no keys are specified then all marked keys are moved.

getMarkedAsDynamicMetadataKeys

protected Set<String> getMarkedAsDynamicMetadataKeys()

linkKey

public void linkKey(String keyLink,
                    String key)

Create a key which is a link to another key, such that if you get the metadata values for the created link it will return the current metadata values of the key it was linked to. NOTE: if the key's metadata values change, then the metadata values for the link key will also be the changed values. If you want to create a key which holds the current value of a key, then create a new metadata key.

Parameters:

keyLink - The name of the link key you wish to create.

key - The key you which to link to (may also be a key link)

unlinkKey

public void unlinkKey(String keyLink)

Removes a key link reference. The key which the key link was linked to remains unchanged.

Parameters:

keyLink - The key link which you wish to destroy.

isLink

public boolean isLink(String key)

Check if the given key name is a key link.

Parameters:

key - The key name in question.

Returns:

True is the given key name is a key link, false if key name is an actual key.

resolveKey

public String resolveKey(String key)

Find the actual key whose value will be returned for the given key. If the given key is a key (not a key link) then the given key will just be returned, otherwise it will trace through key link mapping to find the key which the given key link points to.

Parameters:

key - The name of a key or key link.

Returns:

The key whose value will be returned for the given key or key link.

getReferenceKeyPath

public List<String> getReferenceKeyPath(String key)

Determines the path by which the given key (if it is a key link) links to the key whose value it will return. If the given key is a key link and points to a key then the returning List will be of size 1 and will contain just that key. However, if the given key is a key link which points to another key link then the returning List will be greater than 1 (will depend on how many key links are connected before they actual point to a key. If the given key is a key, then the returning List will be empty.

Parameters:

key - The path to the key whose value will be returned for the give key.

Returns:

A key path List.

replaceMetadata

public void replaceMetadata(PgeTaskMetKeys key,
                            String value)

replaceMetadata

public void replaceMetadata(String key,
                            String value)

Replace the given key's value with the given value. If the given key is a key link, then it will update the value of the key it is linked to if that key is DYNAMIC or LOCAL. If given key is a key link and it links to a STATIC key, then a new LOCAL key will be create.

Parameters:

key - The key or key link for whose value should be replaced.

value - The value to give the given key. Will replace any existing value or will be the value of a newly created LOCAL key.

replaceMetadata

public void replaceMetadata(Metadata metadata)

Replace all key values with the given key values in the provided Metadata. If the key does not exist it will be created.

Parameters:

metadata - Metadata to replace or create.

replaceMetadata

public void replaceMetadata(PgeTaskMetKeys key,
                            List<String> values)

replaceMetadata

public void replaceMetadata(String key,
                            List<String> values)

Replace the given key's values with the given values. If the given key is a key link, then it will update the values of the key it is linked to if that key is DYNAMIC or LOCAL. If given key is a key link and it links to a STATIC key, then a new LOCAL key will be create.

Parameters:

key - The key or key link for whose values should be replaced.

values - The values to give the given key. Will replace any existing values or will be the values of a newly created LOCAL key.

asMetadata

public Metadata asMetadata(PgeMetadata.Type... types)

Combines STATIC, DYNAMIC, and LOCAL metadata into one metadata object. You can restrict which metadata you want combined and change the order in which combining takes place by specifying Type arguments in the order you which precedence to be observed. For example, if you perform the following: pgeMetadata.asMetadata(LOCAL, STATIC) then only LOCAL and STATIC metadata will be combined and LOCAL metadata will trump STATIC metadata if they both contain the same key. If no arguments are specified then DEFAULT_COMBINE_ORDER is used.

Parameters:

types - The Type hierarchy you which to use when metadata is combined, if no args then DEFAULT_COMBINE_ORDER is used.

Returns:

Combined metadata.

getAllMetadata

public List<String> getAllMetadata(PgeTaskMetKeys key,
                                   PgeMetadata.Type... types)

getAllMetadata

public List<String> getAllMetadata(String key,
                                   PgeMetadata.Type... types)

Get metadata values for given key. If Types are specified then it provides the precedence order in which to search for the key. If no Type args are specified then DEFAULT_QUERY_ORDER will be used. For example if you pass in Type args: STATIC, LOCAL then STATIC metadata will first be checked for the key and if it contains it, then it will return the found value, otherwise it will then check LOCAL metadata for the key and if it finds the value it will return it, otherwise null.

Parameters:

key - The key for whose metadata values should be returned.

types - The type hierarchy which should be used, if no Types specified DEFAULT_QUERY_ORDER will be used.

Returns:

Metadata values for given key.

getMetadata

public String getMetadata(PgeTaskMetKeys key,
                          PgeMetadata.Type... types)

getMetadata

public String getMetadata(String key,
                          PgeMetadata.Type... types)

Returns the first value returned by getAllMetadata(String, Type...), if it returns null then this method will also return null.