org.jooq.Scope Maven / Gradle / Ivy
/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Other licenses:
* -----------------------------------------------------------------------------
* Commercial licenses for this work are available. These replace the above
* Apache-2.0 license and offer limited warranties, support, maintenance, and
* commercial database integrations.
*
* For more information, please visit: http://www.jooq.org/licenses
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package org.jooq;
import java.time.Instant;
import java.util.Map;
import org.jooq.conf.Settings;
import org.jooq.impl.DSL;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
/**
* Scope implementations provide access to a variety of objects that are
* available from a given scope.
*
* The scope of the various objects contained in this type (e.g.
* {@link #configuration()}, {@link #settings()}, etc.) are implementation
* dependent and will be specified by the concrete subtype of
* Scope. Examples of such scope types are:
*
* - {@link Context}: Used for a single traversal of a {@link QueryPart}
* expression tree to produce a SQL string and / or a list of bind
* variables.
* - {@link DSLContext}: The {@link DSL} API that creates {@link Query}
* instances in the context of a {@link Configuration}. It shares the wrapped
* {@link Configuration}'s lifecycle.
* - {@link ExecuteContext}: Used for a single execution of a {@link Query},
* containing JDBC resources and other execution relevant objects. Can be
* accessed by the {@link ExecuteListener} SPI.
* - {@link ParseContext}: Used for a single parse call. Can be accessed by
* the {@link ParseListener} SPI.
* - {@link RecordContext}: Used a single record operation, such as
* {@link UpdatableRecord#store()}. Can be accessed by the
* {@link RecordListener} SPI.
* - {@link TransactionContext}: A scope that covers the execution (or
* nesting) of a single transaction. Can be accessed by the
* {@link TransactionListener} SPI.
* - {@link VisitContext}: A scope that that covers a single traversal of a
* {@link QueryPart} expression tree (just like {@link Context}). Can be
* accessed by the {@link VisitListener} SPI.
*
*
* One of Scope's most interesting features for client code
* implementing any SPI is the {@link #data()} map, which provides access to a
* {@link Map} where client code can register user-defined values for the entire
* lifetime of a scope. For instance, in an {@link ExecuteListener}
* implementation that measures time for fetching data, it is perfectly possible
* to store timestamps in that map:
*
*
* class FetchTimeMeasuringListener extends DefaultExecuteListener {
* @Override
* public void fetchStart(ExecuteContext ctx) {
*
* // Put any arbitrary object in this map:
* ctx.data("org.jooq.example.fetch-start-time", System.nanoTime());
* }
*
* @Override
* public void fetchEnd(ExecuteContext ctx) {
*
* // Retrieve that object again in a later step:
* Long startTime = (Long) ctx.data("org.jooq.example.fetch-start-time");
* System.out.println("Time taken: " + (System.nanoTime() - startTime) / 1000 / 1000.0 + " ms");
* }
* }
*
*
* @author Lukas Eder
*/
public interface Scope {
/**
* The time, according to {@link Configuration#clock()}, when this
* {@link Scope} was created.
*/
@NotNull
Instant creationTime();
/**
* The configuration of the current scope.
*/
@NotNull
Configuration configuration();
/**
* Wrap the {@link #configuration()} in a {@link DSLContext}, providing
* access to the configuration-contextual DSL to construct executable
* queries.
*/
@NotNull
DSLContext dsl();
/**
* The settings wrapped by this context.
*
* This method is a convenient way of accessing
* configuration().settings().
*/
@NotNull
Settings settings();
/**
* The {@link SQLDialect} wrapped by this context.
*
* This method is a convenient way of accessing
* configuration().dialect().
*/
@NotNull
SQLDialect dialect();
/**
* The {@link SQLDialect#family()} wrapped by this context.
*
* This method is a convenient way of accessing
* configuration().family().
*/
@NotNull
SQLDialect family();
/**
* Get all custom data from this Scope.
*
* This is custom data that was previously set to the context using
* {@link #data(Object, Object)}. Use custom data if you want to pass data
* to {@link QueryPart} objects for a given {@link Scope}.
*
* @return The custom data. This is never null
*/
@NotNull
Map data();
/**
* Get some custom data from this Scope.
*
* This is custom data that was previously set to the context using
* {@link #data(Object, Object)}. Use custom data if you want to pass data
* to {@link QueryPart} objects for a given {@link Scope}
*
* @param key A key to identify the custom data
* @return The custom data or null if no such data is contained
* in this Scope
*/
@Nullable
Object data(Object key);
/**
* Set some custom data to this Scope.
*
* This is custom data that was previously set to the context using
* {@link #data(Object, Object)}. Use custom data if you want to pass data
* to {@link QueryPart} objects for a given {@link Scope}.
*
* @param key A key to identify the custom data
* @param value The custom data
* @return The previously set custom data or null if no data
* was previously set for the given key
*/
@Nullable
Object data(Object key, Object value);
}