org.jooq.Scope Maven / Gradle / Ivy
/*
* Copyright (c) 2009-2016, Data Geekery GmbH (http://www.datageekery.com)
* All rights reserved.
*
* 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
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* http://www.apache.org/licenses/LICENSE-2.0
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* 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.
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* limitations under the License.
*
* Other licenses:
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* database integrations.
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* For more information, please visit: http://www.jooq.org/licenses
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package org.jooq;
import java.util.Map;
import org.jooq.conf.Settings;
/**
* 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 ExecuteContext}: A scope that covers a single execution of a
* {@link Query}
* - {@link Context}: A scope that covers a single traversal of a
* {@link QueryPart} expression tree to produce a SQL string and / or a list of
* bind variables.
* - {@link VisitContext}: A scope that that covers a single traversal of a
* {@link QueryPart} expression tree (just like {@link Context}), in the
* presence of at least one {@link VisitListener}.
* - {@link RecordContext}: A scope that covers a single record operation,
* such as {@link UpdatableRecord#store()}.
* - {@link TransactionContext}: A scope that covers the execution (or
* nesting) of a single transaction.
*
*
* 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");
* }
* }
*
* This method is a convenient way of accessing
* configuration().settings().
*/
Settings settings();
/**
* The {@link SQLDialect} wrapped by this context.
*
* This method is a convenient way of accessing
* configuration().dialect().
*/
SQLDialect dialect();
/**
* The {@link SQLDialect#family()} wrapped by this context.
*
* This method is a convenient way of accessing
* configuration().dialect().family().
*/
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
*/
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
*/
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
*/
Object data(Object key, Object value);
}