Package com.blazebit.query

Interface QueryContext

All Superinterfaces:

AutoCloseable

public interface QueryContext
extends AutoCloseable

Context object for creating query sessions. When the application has finished using the QueryContext, and/or at application shutdown, the application should close the QueryContext. Once a QueryContext has been closed, all its QuerySession objects are considered to be in the closed state. The object is thread-safe and should be reused instead of rebuilt, since it is heavyweight.

Since:

1.0.0

Method Summary

Modifier and Type	Method	Description
void	close()	Closes the QueryContext and all associated QuerySession to free up resources.
default QuerySession	createSession()	Creates a new QuerySession with default configuration.
QuerySession	createSession(Map<String,Object> properties)	Creates a new QuerySession.
Metamodel	getMetamodel()	Returns the metamodel of this QueryContext.
boolean	isOpen()	Returns whether the QueryContext is open.
<T> T	unwrap(Class<T> cls)	Return an object of the specified type to allow access to the provider-specific API.

Method Details

createSession

default QuerySession createSession()

Creates a new QuerySession with default configuration.

Returns:

a new QuerySession

Throws:

IllegalStateException - if the QueryContext has already been closed

createSession

QuerySession createSession(Map<String,Object> properties)

Creates a new QuerySession. The given configuration properties will override the default configuration if possible.

Parameters:

properties - Additional configuration that overrides the default configuration if possible

Returns:

a new QuerySession

Throws:

IllegalStateException - if the QueryContext has already been closed

getMetamodel

Metamodel getMetamodel()

Returns the metamodel of this QueryContext.

Returns:

The metamodel of this QueryContext

unwrap

<T> T unwrap(Class<T> cls)

Return an object of the specified type to allow access to the provider-specific API. If the implementation does not support the specified class, the IllegalArgumentException is thrown.

Type Parameters:

T - The return type

Parameters:

cls - the class of the object to be returned

Returns:

The unwrapped object

Throws:

IllegalArgumentException - if the type is not supported

isOpen

boolean isOpen()

Returns whether the QueryContext is open.

Returns:

Whether the QueryContext is open

close

void close()

Closes the QueryContext and all associated QuerySession to free up resources.

Specified by:

close in interface AutoCloseable

Throws:

IllegalStateException - if the QueryContext has already been closed