com.redhat.lightblue.crud.mongo

Class Translator

java.lang.Object

com.redhat.lightblue.crud.mongo.Translator

public class Translator
extends Object

Translations between BSON and JSON. This class is thread-safe, and can be shared between threads

Field Summary

Fields

Modifier and Type	Field and Description
static String	ERR_INVALID_COMPARISON
static String	ERR_INVALID_FIELD
static String	ERR_INVALID_OBJECTTYPE
static String	ERR_NO_OBJECT_TYPE
static com.redhat.lightblue.util.Path	ID_PATH
static com.redhat.lightblue.util.Path	OBJECT_TYPE
static String	OBJECT_TYPE_STR

Constructor Summary

Constructors

Constructor and Description
Translator(com.redhat.lightblue.crud.MetadataResolver mdResolver, com.fasterxml.jackson.databind.node.JsonNodeFactory factory) Constructs a translator using the given metadata resolver and factory

Method Summary

Methods

Modifier and Type	Method and Description
void	addInvisibleFields(com.mongodb.DBObject oldDBObject, com.mongodb.DBObject newObject, com.redhat.lightblue.metadata.EntityMetadata md) Add any fields in the old object that are not in the metadata of the new object
static Object	createIdFrom(Object source) Creates appropriate identifier object given source data.
static Object	getDBObject(com.mongodb.DBObject start, com.redhat.lightblue.util.Path p)
static Set<com.redhat.lightblue.util.Path>	getRequiredFields(com.redhat.lightblue.metadata.EntityMetadata md, com.redhat.lightblue.query.Projection p, com.redhat.lightblue.query.QueryExpression q, com.redhat.lightblue.query.Sort s) Returns all the fields required to evaluate the given projection, query, and sort
com.mongodb.DBObject	toBson(com.redhat.lightblue.util.JsonDoc doc) Translates a JSON document to DBObject.
com.mongodb.DBObject[]	toBson(List<? extends com.redhat.lightblue.util.JsonDoc> docs) Translates a list of JSON documents to DBObjects.
com.redhat.lightblue.util.JsonDoc	toJson(com.mongodb.DBObject object) Traslates a DBObject document to Json document
List<com.redhat.lightblue.util.JsonDoc>	toJson(List<com.mongodb.DBObject> objects) Translates DBObjects into Json documents
com.mongodb.DBObject	translate(com.redhat.lightblue.metadata.EntityMetadata md, com.redhat.lightblue.query.QueryExpression query) Translates a query to Mongo query
com.mongodb.DBObject	translate(com.redhat.lightblue.metadata.EntityMetadata md, com.redhat.lightblue.query.UpdateExpression expr) Tranlates an update expression to Mongo query
com.mongodb.DBObject	translate(com.redhat.lightblue.query.Sort sort) Translates a sort expression to Mongo sort expression
static String	translateJsPath(com.redhat.lightblue.util.Path p) Translate a path to a javascript path Path cannot have *.
static String	translatePath(com.redhat.lightblue.util.Path p) Translate a path to a mongo path Any * in the path is removed.
com.mongodb.DBObject	translateProjection(com.redhat.lightblue.metadata.EntityMetadata md, com.redhat.lightblue.query.Projection p, com.redhat.lightblue.query.QueryExpression q, com.redhat.lightblue.query.Sort s) Writes a MongoDB projection containing fields to evaluate the projection, sort, and query

Methods inherited from class java.lang.Object

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

Field Detail

OBJECT_TYPE_STR

public static final String OBJECT_TYPE_STR

See Also:

Constant Field Values

OBJECT_TYPE

public static final com.redhat.lightblue.util.Path OBJECT_TYPE

ID_PATH

public static final com.redhat.lightblue.util.Path ID_PATH

ERR_NO_OBJECT_TYPE

public static final String ERR_NO_OBJECT_TYPE

See Also:

Constant Field Values

ERR_INVALID_OBJECTTYPE

public static final String ERR_INVALID_OBJECTTYPE

See Also:

Constant Field Values

ERR_INVALID_FIELD

public static final String ERR_INVALID_FIELD

See Also:

Constant Field Values

ERR_INVALID_COMPARISON

public static final String ERR_INVALID_COMPARISON

See Also:

Constant Field Values

Constructor Detail

Translator

public Translator(com.redhat.lightblue.crud.MetadataResolver mdResolver,
          com.fasterxml.jackson.databind.node.JsonNodeFactory factory)

Constructs a translator using the given metadata resolver and factory

Method Detail

translatePath

public static String translatePath(com.redhat.lightblue.util.Path p)

Translate a path to a mongo path Any * in the path is removed. Array indexes remain intact.

translateJsPath

public static String translateJsPath(com.redhat.lightblue.util.Path p)

Translate a path to a javascript path Path cannot have *. Indexes are put into brackets

toBson

public com.mongodb.DBObject[] toBson(List<? extends com.redhat.lightblue.util.JsonDoc> docs)

Translates a list of JSON documents to DBObjects. Translation is metadata driven.

toBson

public com.mongodb.DBObject toBson(com.redhat.lightblue.util.JsonDoc doc)

Translates a JSON document to DBObject. Translation is metadata driven.

toJson

public com.redhat.lightblue.util.JsonDoc toJson(com.mongodb.DBObject object)

Traslates a DBObject document to Json document

toJson

public List<com.redhat.lightblue.util.JsonDoc> toJson(List<com.mongodb.DBObject> objects)

Translates DBObjects into Json documents

addInvisibleFields

public void addInvisibleFields(com.mongodb.DBObject oldDBObject,
                      com.mongodb.DBObject newObject,
                      com.redhat.lightblue.metadata.EntityMetadata md)

Add any fields in the old object that are not in the metadata of the new object

getDBObject

public static Object getDBObject(com.mongodb.DBObject start,
                 com.redhat.lightblue.util.Path p)

translate

public com.mongodb.DBObject translate(com.redhat.lightblue.query.Sort sort)

Translates a sort expression to Mongo sort expression

translate

public com.mongodb.DBObject translate(com.redhat.lightblue.metadata.EntityMetadata md,
                             com.redhat.lightblue.query.QueryExpression query)

Translates a query to Mongo query

Parameters:

md - Entity metadata

query - The query expression

translate

public com.mongodb.DBObject translate(com.redhat.lightblue.metadata.EntityMetadata md,
                             com.redhat.lightblue.query.UpdateExpression expr)
                               throws CannotTranslateException

Tranlates an update expression to Mongo query

Parameters:

md - Entity metedata

expr - Update expression If the update expresssion is something that can be translated into a mongo update expression, translation is performed. Otherwise, CannotTranslateException is thrown, and the update operation must be performed using the Updaters.

Throws:

CannotTranslateException

getRequiredFields

public static Set<com.redhat.lightblue.util.Path> getRequiredFields(com.redhat.lightblue.metadata.EntityMetadata md,
                                                    com.redhat.lightblue.query.Projection p,
                                                    com.redhat.lightblue.query.QueryExpression q,
                                                    com.redhat.lightblue.query.Sort s)

Returns all the fields required to evaluate the given projection, query, and sort

Parameters:

md - Entity metadata

p - Projection

q - Query

s - Sort All arguments are optional. The returned set contains the fields required to evaluate all the non-null expressions

translateProjection

public com.mongodb.DBObject translateProjection(com.redhat.lightblue.metadata.EntityMetadata md,
                                       com.redhat.lightblue.query.Projection p,
                                       com.redhat.lightblue.query.QueryExpression q,
                                       com.redhat.lightblue.query.Sort s)

Writes a MongoDB projection containing fields to evaluate the projection, sort, and query

createIdFrom

public static Object createIdFrom(Object source)

Creates appropriate identifier object given source data. If the source can be converted to an ObjectId it is, else it is returned as a String.

Parameters:

source - input data

Returns:

ObjectId if possible else String