org.lacibus.storeaccess

Class Executor

java.lang.Object

org.lacibus.storeaccess.Executor

All Implemented Interfaces:

java.io.Serializable

public class Executor
extends java.lang.Object
implements java.io.Serializable

An instance of this class executes on a triple store a set of commands contained in a JSON array.

The following commands can be supplied for execution. A string, a handle, an item, or an access level is supplied as a text string in quotes. A non-item can be a boolean (true or false), an integer, a decimal number, or a text string in quotes. A b64 is a base64-encoded binary value. A source is supplied as an integer. A json object is supplied as the textual representation of a JSON object ({ . . . }). The text string describing an item or an access level can be a handle set in a previous command, the textual representation of an item identifier (sourcenr:itemnr) or a numeric source identifier and the name of a named item in that source, separated by a colon (sourcenr:name). It MUST NOT be a textual source name and the name of a named item in that source.

The result returned from the execution is a map of the values assigned to handles.

Get or create a named item.

    "command"="named item";
    "source"=source;
    "name"=string;
    "handle"=handle
 

Get the unique subject with a given verb and item object.

    "command"="get unique subject with item object";
    "verb"=item;
    "object"=item;
    "handle"=handle (optional)
 

Get the unique subject with a given verb and item object, creating it in the given source and with the given access levels if it does not exist.

    "command"="unique subject with item object";
    "source"=source;
    "read"=access level;
    "write"=access level;
    "verb"=item;
    "object"=item;
    "handle"=handle (optional)
 

Get the unique subject with a given verb and boolean, integral, real or string object.

    "command"="get unique subject with non-item object";
    "verb"=item;
    "object"=non-item;
    "handle"=handle (optional)
 

Get the unique subject with a given verb and boolean, integral, real or string object, creating it in the given source and with the given access levels if it does not exist.

    "command"="unique subject with non-item object";
    "source"=source;
    "read"=access level;
    "write"=access level;
    "verb"=item;
    "object"=non-item;
    "handle"=handle (optional)
 

Get the unique subject with a given verb and binary object.

    "command"="get unique subject with binary object";
    "verb"=item;
    "object"=b64;
    "handle"=handle (optional)
 

Get the unique subject with a given verb and binary object, creating it in the given source and with the given access levels if it does not exist.

    "command"="unique subject with binary object";
    "source"=source;
    "read"=access level;
    "write"=access level;
    "verb"=item;
    "object"=b64;
    "handle"=handle (optional)
 

Get the item that is the unique object with a given subject and verb, creating it in the given source and with the given access levels, and also creating the appropriate triple, if it does not exist.

    "command"="unique item object";
    "source"=source;
    "subject"=item;
    "verb"=item;
    "read"=access level;
    "write"=access level;
    "handle"=handle (optional)
 

Create an item.

    "command"="create item";
    "source"=source;
    "read"=access level;
    "write"=access level;
    "handle"=handle
 

Ensure that there is a unique triple with a given subject, verb and object, where the object is an item.

    "command"="put triple with item object";
    "subject"=item;
    "verb"=item;
    "object"=item
 

Ensure that there is a unique triple with a given subject, verb and object, where the object is a boolean, integer, real, or string.

    "command"="put triple with non-item object";
    "subject"=item;
    "verb"=item;
    "object"=non-item
 

Ensure that there is a unique triple with a given subject, verb and object, where the object is a binary.

    "command"="put triple with non-item object";
    "subject"=item;
    "verb"=item;
    "object"=b64
 

Ensure that there is a unique triple with a given subject and verb, and that it has the given object, which is an item.

    "command"="set unique item object";
    "subject"=item;
    "verb"=item;
    "object"=item
 

Ensure that there is a unique triple with a given subject and verb, and that it has the given object, which is a boolean, integer, real or string.

    "command"="set unique non-item object";
    "subject"=item;
    "verb"=item;
    "object"=non-item
 

Ensure that there is a unique triple with a given subject and verb, and that it has the given object, which is a binary.

    "command"="set unique non-item object";
    "subject"=item;
    "verb"=item;
    "object"=b64
 

Ensure that there is a unique triple with a given subject and verb, and that it has the given object, which is the textual representation of a JSON object.

    "command"="set unique json object";
    "subject"=item;
    "verb"=item;
    "object"=json object
 

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
Executor(TripleStore store) Create an executor

Method Summary

Modifier and Type	Method and Description
java.util.Map<java.lang.String,Datum>	execute(org.json.simple.JSONArray script, java.util.Map<java.lang.String,Datum> binaries, StoreSession session) Execute the commands in a JSON array
void	executeJsonCommand(org.json.simple.JSONObject jo, java.util.Map<java.lang.String,Datum> handles, java.util.Map<java.lang.String,Datum> binaries, StoreSession session) Execute a command
AccessLevel	getAccessLevelFromJson(java.lang.String name, org.json.simple.JSONObject jo, java.util.Map<java.lang.String,Datum> assignments, StoreSession session) Get an access level specified in a JSON object
Datum	getBinaryFromJson(java.lang.String name, java.util.Map<java.lang.String,Datum> binaries, org.json.simple.JSONObject jo) Get a binary value from a JSON object and a map of binary values
Datum	getBoolIntRealOrStringFromJson(java.lang.String name, org.json.simple.JSONObject jo, StoreSession session) Get a boolean, integer, real, or string from a JSON object
Item	getItemFromJson(java.lang.String name, org.json.simple.JSONObject jo, java.util.Map<java.lang.String,Datum> assignments, StoreSession session) Get an item specified in a JSON object
org.json.simple.JSONObject	getJsonCommand(java.lang.Object obj) Get a command from an object
java.lang.Long	getLongFromJson(java.lang.String name, org.json.simple.JSONObject jo) Get a Long value from a JSON object
Item	getNamedItem(java.lang.String spec, StoreSession session) Get a named item from its specification
java.lang.String	getStringFromJson(java.lang.String name, org.json.simple.JSONObject jo) Get a String value from a JSON object

Methods inherited from class java.lang.Object

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

Constructor Detail

Executor

public Executor(TripleStore store)

Create an executor

Parameters:

store - the triple store on which the commands are executed

Method Detail

execute

public java.util.Map<java.lang.String,Datum> execute(org.json.simple.JSONArray script,
                                                     java.util.Map<java.lang.String,Datum> binaries,
                                                     StoreSession session)
                                              throws java.lang.Exception

Execute the commands in a JSON array

Parameters:

script - a JSON array containing commands to be executed

session - the requesting store session

Throws:

java.lang.Exception

getJsonCommand

public org.json.simple.JSONObject getJsonCommand(java.lang.Object obj)
                                          throws InputException

Get a command from an object

Parameters:

obj - an object

Returns:

the object cast as a JSON object if it can be so cast

Throws:

InputException

executeJsonCommand

public void executeJsonCommand(org.json.simple.JSONObject jo,
                               java.util.Map<java.lang.String,Datum> handles,
                               java.util.Map<java.lang.String,Datum> binaries,
                               StoreSession session)
                        throws java.lang.Exception

Execute a command

Parameters:

jo - a JSON object containing the command to be executed

handles - the handles for items created by previous commands, and to which a new handle can be added if an item is created by this command.

session - the requesting store session

Throws:

InputException

java.lang.Exception

getLongFromJson

public java.lang.Long getLongFromJson(java.lang.String name,
                                      org.json.simple.JSONObject jo)

Get a Long value from a JSON object

Parameters:

name - the name in a name-value pair in the JSON object

jo - a JSON object

Returns:

the value of the name-value pair if it can be cast as Long

getStringFromJson

public java.lang.String getStringFromJson(java.lang.String name,
                                          org.json.simple.JSONObject jo)

Get a String value from a JSON object

Parameters:

name - the name in a name-value pair in the JSON object

jo - a JSON object

Returns:

the value of the name-value pair if it can be cast as String

getBoolIntRealOrStringFromJson

public Datum getBoolIntRealOrStringFromJson(java.lang.String name,
                                            org.json.simple.JSONObject jo,
                                            StoreSession session)

Get a boolean, integer, real, or string from a JSON object

Parameters:

name - the name in a name-value pair in the JSON object

jo - a JSON object

session - the requesting store session

Returns:

the Boolean, Long, Double or String that is the value of the name-value pair if this can be so cast.

getBinaryFromJson

public Datum getBinaryFromJson(java.lang.String name,
                               java.util.Map<java.lang.String,Datum> binaries,
                               org.json.simple.JSONObject jo)
                        throws AccessException

Get a binary value from a JSON object and a map of binary values

Parameters:

name - the name in a name-value pair in the JSON object

binaries - a map giving the binary values referred to in the JSON object

jo - a JSON object

Returns:

the byte array that is the base64-decoded value of the name-value pair if this can be cast to a string.

Throws:

AccessException

getAccessLevelFromJson

public AccessLevel getAccessLevelFromJson(java.lang.String name,
                                          org.json.simple.JSONObject jo,
                                          java.util.Map<java.lang.String,Datum> assignments,
                                          StoreSession session)
                                   throws java.lang.Exception

Get an access level specified in a JSON object

Parameters:

name - the name in a name-value pair in the JSON object

jo - a JSON object

assignments - the assignments created by previous commands

session - the requesting store session

Returns:

the access level specified by the value of the name-value pair if this can be cast as String

Throws:

java.lang.Exception

getItemFromJson

public Item getItemFromJson(java.lang.String name,
                            org.json.simple.JSONObject jo,
                            java.util.Map<java.lang.String,Datum> assignments,
                            StoreSession session)
                     throws java.lang.Exception

Get an item specified in a JSON object

Parameters:

name - the name in a name-value pair in the JSON object

jo - a JSON object

assignments - the assignments created by previous commands

session - the requesting store session

Returns:

the item specified by the value of the name-value pair if this can be cast as String

Throws:

java.lang.Exception

getNamedItem

public Item getNamedItem(java.lang.String spec,
                         StoreSession session)
                  throws TripleStoreNonFatalException,
                         SourceConnectorException,
                         TripleStoreFatalException,
                         NotInOperationException

Get a named item from its specification

Parameters:

spec - a specification of a named item

session - the requesting store session

Returns:

the specified named item, or null if it cannot be found

Throws:

TripleStoreNonFatalException

SourceConnectorException

TripleStoreFatalException

NotInOperationException