io.innerloop.neo4j.client

Interface Connection

All Known Implementing Classes:

RestConnectionImpl

public interface Connection

A Connection represents an interaction with the database. All Neo4J Cypher Queries must run within a Connection, even reads. Thus all reads are always READ COMMITTED.

Connections can support the execution of multiple statements. Statements are executed in order of insertion.

Method Summary

Modifier and Type	Method and Description
void	add(Statement statement) Adds the given statement to execute within this Connection.
void	commit() Commits this Connection to Neo4J.
void	flush() Flushes the Statements currently held by this Connection to Neo4J.
java.time.OffsetDateTime	getExpiry() Retrieves when this Connection will expire.
java.util.List<Statement>	getStatements() Retrieves any Statements that have not been executed in the cache.
void	resetExpiry() Extends the life of this Connection.
void	rollback() Rolls back any changes made by this Connection.

Method Detail

add

void add(Statement statement)

Adds the given statement to execute within this Connection. This method can be called multiple times with different statements before calling flush(), commit() or rollback().

Parameters:

statement - A statement that should be added to this Connection.

getStatements

java.util.List<Statement> getStatements()

Retrieves any Statements that have not been executed in the cache.

This will be empty if flush or commit is called before accessing this.

Returns:

A list of statements scheduled to be executed.

getExpiry

java.time.OffsetDateTime getExpiry()

Retrieves when this Connection will expire.

Returns:

A date time specifying when this Connection will expire..

resetExpiry

void resetExpiry()

Extends the life of this Connection. Can be used in conjunction with getExpiry() in a daemon thread to monitor expiry. TODO: NOT CURRENTLY THREADSAFE

flush

void flush()

Flushes the Statements currently held by this Connection to Neo4J. Once this method is called any statements issued before a call to this method will have their results available. Note that any reads in this Connection will still only be READ COMMITTED. Writes in this Connection will be UNCOMMITTED until commit() is called. That is this Connection will be fully isolated until commit() is called. Calling Rollback will not roll back statements to this point (like a savepoint) rather it will rollback the entire Connection including any flush()s called previously.

Throws:

Neo4jServerException - If an error occurs in flushing to the database. It is generally expected that a client will not be able to recover from this error.

Neo4jServerMultiException - If the Neo4J Server responds with with multiple errors (this probably doesn't happen but there is no way to know for sure).

commit

void commit()

Commits this Connection to Neo4J.

Throws:

Neo4jClientException - If an error occurs in committing this Connection to the database. Clients may then choose to catch and rollback this Connection if desired.

rollback

void rollback()

Rolls back any changes made by this Connection.

Throws:

Neo4jServerException - If an error occurs trying to rollback the Connection.

Neo4jServerMultiException - If the Neo4J Server responds with with multiple errors (this probably doesn't happen but there is no way to know for sure).