/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
package org.apache.deltaspike.core.api.projectstage;
import org.apache.deltaspike.core.util.ServiceUtils;
import javax.enterprise.inject.Typed;
import java.io.Serializable;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.logging.Logger;
/**
* This class is the base of all ProjectStages. A ProjectStage identifies the environment the application currently runs
* in. It provides the same functionality as the JSF2 ProjectStage but has a few additional benefits:
* <ul>
* <li>it works for JSF 1.0, JSF 1.1 and JSF 1.2 applications</li>
* <li>it works in pure backends and unit tests without any JSF API</li>
* <li>it is dynamic. Everyone can add their own ProjectStages!</li>
* </ul>
*
* <p>
* Technically this is kind of a 'dynamic enum'.</p>
*
* <p>
* The following ProjectStages are provided by default:</p>
* <ul>
* <li>UnitTest</li>
* <li>Development</li>
* <li>SystemTest</li>
* <li>IntegrationTest</li>
* <li>Staging</li>
* <li>Production</li>
* </ul>
*
* <p>
* The following resolution mechanism is used to determine the current ProjectStage:</p>
* <ul>
* <li>TODO specify!</li>
* </ul>
*
* <p>
* New ProjectStages can be added via the {@link java.util.ServiceLoader} mechanism. A class deriving from
* {@link ProjectStage} must be provided and used for creating a single static instance of it.</p>
*
* <p>
* Custom ProjectStages can be implemented by writing anonymous ProjectStage members into a registered
* {@link ProjectStageHolder} as shown in the following example:</p>
*
* <pre>
* package org.apache.deltaspike.test.core.api.projectstage;
* public class TestProjectStages implements ProjectStageHolder {
* public static final class MyOwnProjectStage extends ProjectStage {};
* public static final MyOwnProjectStage MyOwnProjectStage = new MyOwnProjectStage();
*
* public static final class MyOtherProjectStage extends ProjectStage {};
* public static final MyOtherProjectStage MyOtherProjectStage = new MyOtherProjectStage();
* }
* </pre>
*
* <p>
* To activate those ProjectStages, you have to register the ProjectStageHolder class to get picked up via the
* ServiceLoader mechanism. Simply create a file
* <pre>
* META-INF/services/org.apache.deltaspike.core.api.projectstage.ProjectStageHolder
* </pre> which contains the fully qualified class name of custom ProjectStageHolder implementation:
* <pre>
* # this class now gets picked up by java.util.ServiceLoader
* org.apache.deltaspike.test.core.api.projectstage.TestProjectStages
* </pre>
* </p>
*
* <p>
* You can use your own ProjectStages exactly the same way as all the ones provided by the system:
* <pre>
* ProjectStage myOwnPs = ProjectStage.valueOf("MyOwnProjectStage");
* if (myOwnPs.equals(MyOwnProjectStage.MyOwnProjectStage)) ...
* </pre>
* </p>
*
* <p>
* <b>Note:</b> DeltaSpike will only find {@link ProjectStageHolder}s which are accessible by this very class. If you
* deploy the deltaspike-core jar to a shared EAR classloader, it will e.g. <i>not</i> be able to register ProjectStages
* defined in a web application's WEB-INF/classes directory!
* </p>
*
*/
@Typed()
public abstract class ProjectStage implements Serializable
{
private static final long serialVersionUID = -1210639662598734888L;
/**
* This map contains a static map with all registered projectStages.
*
* We don't need to use a ConcurrentHashMap because writing to it will
* only be performed in the static initializer block which is guaranteed
* to be atomic by the VM spec.
*/
private static Map<String, ProjectStage> projectStages = new HashMap<String, ProjectStage>();
/**
* All the registered ProjectStage values.
* We don't need to make this volatile because of the classloader guarantees of
* the VM.
*/
private static ProjectStage[] values = null;
/**
* logger for the ProjectStage
*/
private static final Logger LOG = Logger.getLogger(ProjectStage.class.getName());
/**
* The static initializer block will register all custom ProjectStages
* by simply touching their classes due loading it with the.
* {@link java.util.ServiceLoader}.
*/
static
{
List<ProjectStageHolder> projectStageHolders =
ServiceUtils.loadServiceImplementations(ProjectStageHolder.class);
for (ProjectStageHolder projectStageHolder : projectStageHolders)
{
LOG.fine("registering ProjectStages from ProjectStageHolder " + projectStageHolder.getClass().getName());
}
}
/** the name of the ProjectStage*/
private String psName;
/**
* The protected constructor will register the given ProjectStage via its name.
* The name is returned by the {@link #toString()} method of the ProjectStage.
*/
protected ProjectStage()
{
String projectStageClassName = getClass().getSimpleName();
psName = projectStageClassName;
init(projectStageClassName, this);
}
/**
* This function exists to prevent findbugs from complaining about
* setting a static member from a non-static function.
*
* @param projectStageClassName name of the project-stage
* @param projectStage instance of the project-stage
*/
private static void init(String projectStageClassName, ProjectStage projectStage)
{
if (!projectStages.containsKey(projectStageClassName))
{
projectStages.put(projectStageClassName, projectStage);
}
else
{
throw new IllegalArgumentException("ProjectStage with name " + projectStageClassName + " already exists!");
}
// we cannot do this in the static block since it's not really deterministic
// when all ProjectStages got resolved.
values = projectStages.values().toArray(new ProjectStage[ projectStages.size() ]);
}
/**
* @param projectStageClassName the name of the ProjectStage
* @return the ProjectStage which is identified by it's name
*/
public static ProjectStage valueOf(String projectStageClassName)
{
return projectStages.get(projectStageClassName);
}
/**
* Exposes all registered {@link ProjectStage} implementations.
*
* @return provided and custom ProjectStage implementations
*/
public static ProjectStage[] values()
{
ProjectStage[] result = new ProjectStage[values.length];
System.arraycopy(values, 0, result, 0, values.length);
return result;
}
/**
* {@inheritDoc}
*/
@Override
public String toString()
{
return psName;
}
// CHECKSTYLE:OFF
/**
* Project-stage for unit-tests
*/
@Typed()
public static final class UnitTest extends ProjectStage implements TestStage
{
private static final long serialVersionUID = -7910349894182034559L;
}
/**
* Type-safe {@link ProjectStage}
*/
public static final UnitTest UnitTest = new UnitTest();
/**
* Project-stage for development
*/
@Typed()
public static final class Development extends ProjectStage
{
private static final long serialVersionUID = 1977308277341527250L;
}
/**
* Type-safe {@link ProjectStage}
*/
public static final Development Development = new Development();
/**
* Project-stage for system-tests
*/
@Typed()
public static final class SystemTest extends ProjectStage implements TestStage
{
private static final long serialVersionUID = -7444003351466372539L;
}
/**
* Type-safe {@link ProjectStage}
*/
public static final SystemTest SystemTest = new SystemTest();
/**
* Project-stage for integration-tests
*/
@Typed()
public static final class IntegrationTest extends ProjectStage implements TestStage
{
private static final long serialVersionUID = 2034474361615347127L;
}
/**
* Type-safe {@link ProjectStage}
*/
public static final IntegrationTest IntegrationTest = new IntegrationTest();
/**
* Project-stage for staging
*/
@Typed()
public static final class Staging extends ProjectStage
{
private static final long serialVersionUID = -8426149532860809553L;
}
/**
* Type-safe {@link ProjectStage}
*/
public static final Staging Staging = new Staging();
/**
* Default project-stage for production
*/
@Typed()
public static final class Production extends ProjectStage
{
private static final long serialVersionUID = -4030601958667812084L;
}
/**
* Type-safe {@link ProjectStage}
*/
public static final Production Production = new Production();
// CHECKSTYLE:ON
}