OperationStepHandler 实现

如 ResourceDefinition 实现 中 Subsystem 树状结构图中所示，本部分说明实线连接的 root 节点和二级 type 节点对应的 处理器 的实现, 共有三类处理器：

  1. 节点添加处理器和移除处理器 - SubsystemAddHandler, SubsystemRemoveHandler, TypeAddHandler, TypeRemoveHandler

  2. 属性读处理器和写处理器 - TrackerShowCoolReadHandler, TrackerShowCoolWriteHandler, TypeTickReadHandler, TypeTickWriteHandler

  3. 节点操作处理器 - TrackerDisableAllHandler, TrackerListAllHandler, TrackerListCoolHandler, TypeDisableHandler, TypeEnableHandler

其中以 Subsystem 或 Tracker 开头的处理器与 root 节点相关，以 Type 开头的则与二级 type 节点，其 UML 类图如下:

Wildfly Extending Acme

节点添加处理器和移除处理器实现

SubsystemAddHandler

root 节点(Subsystem)的 添加处理器 实现类 SubsystemAddHandler 继承了抽象类 AbstractBoottimeAddStepHandler，它主要功能是在 WildFly 启动添加 Tracker Subsystem 时注册一个 deployer hook，创建一个新的 TrackerDeploymentService:

@Override
protected void performBoottime(OperationContext context, ModelNode operation, ModelNode model)throws OperationFailedException {

    log.info("Add a deployer hook, add a new service: " + TrackerDeploymentService.NAME);

    // Add a hook into deployers, which subsystem will be noticed once a deployment be deploy
    context.addStep(new AbstractDeploymentChainStep() {
        public void execute(DeploymentProcessorTarget processorTarget) {
            processorTarget.addDeploymentProcessor(SUBSYSTEM_NAME, SubsystemDeploymentProcessor.PHASE, SubsystemDeploymentProcessor.PRIORITY, new SubsystemDeploymentProcessor());
            }
    }, OperationContext.Stage.RUNTIME);

    // Add TrackerRuntimeService
    context.getServiceTarget()
           .addService(TrackerDeploymentService.NAME, new TrackerDeploymentService())
           .setInitialMode(Mode.ACTIVE)
           .install();
}

完整实现代码参照 SubsystemAddHandler.java

SubsystemDeploymentProcessor 实现参照 添加 deployers hook

SubsystemRemoveHandler

root 节点(Subsystem)的 移除处理器 实现类 SubsystemRemoveHandler 继承了抽象类 AbstractRemoveStepHandler，它的主要功能是在 Tracker Subsystem 移除时移除 TrackerDeploymentService:

@Override
protected void performRuntime(OperationContext context,ModelNode operation, ModelNode model)throws OperationFailedException {

    log.info("Remove Service: " + TrackerDeploymentService.NAME);

    context.removeService(TrackerDeploymentService.NAME);
}

完整实现代码参照 SubsystemRemoveHandler.java

TypeAddHandler

二级 type 节点的 添加处理器 实现类 TypeAddHandler 继承抽象类 AbstractAddStepHandler，它的主要功能是初始化添加一个 TrackerService:

@Override
protected void performRuntime(OperationContext context, ModelNode operation, ModelNode model) throws OperationFailedException {

    String suffix = PathAddress.pathAddress(operation.get(ModelDescriptionConstants.ADDRESS)).getLastElement().getValue();
    long tick = TICK.resolveModelAttribute(context,model).asLong();
    TrackerService service = new TrackerService(suffix, tick);
    ServiceName name = TrackerService.createServiceName(suffix);

    log.info("Add a new service: " + name);

    context.getServiceTarget()
           .addService(name, service)
	   .addDependency(TrackerDeploymentService.NAME, TrackerDeploymentService.class, service.getDeploymentService())
           .setInitialMode(Mode.ACTIVE)
           .install();
}

完整实现代码参照 TypeAddHandler.java

TypeRemoveHandler

二级 type 节点的 移除处理器 实现类 TypeAddHandler 继承了抽象类 AbstractRemoveStepHandler，它的主要功能是在移除节点时移除对应的TrackerService:

@Override
protected void performRuntime(OperationContext context, ModelNode operation, ModelNode model) throws OperationFailedException {
    String suffix = PathAddress.pathAddress(operation.get(ModelDescriptionConstants.ADDRESS)).getLastElement().getValue();
    ServiceName name = TrackerService.createServiceName(suffix);
    log.info("Remove Service: " + name);
    context.removeService(name);
}

完整实现代码参照 TypeRemoveHandler.java

属性读处理器和写处理器实现

root 节点(Subsystem)有一个属性 show-cool-deployments，通过管理命令行可以进行读写操作

/subsystem=tracker:read-attribute(name=show-cool-deployments)
/subsystem=tracker:write-attribute(name=show-cool-deployments,value=false)

读写操作是通过属性的 TrackerShowCoolReadHandler 和 TrackerShowCoolWriteHandler 实现的, TrackerShowCoolReadHandler 实现了接口 OperationStepHandler，它主要功能是从 TrackerDeploymentService 中读取 ShowCool 变量的值并设定给返回结果:

@Override
public void execute(OperationContext context, ModelNode operation) throws OperationFailedException {

    ServiceController<?> controller = context.getServiceRegistry(true).getService(TrackerDeploymentService.NAME);
    if(controller != null) {
        TrackerDeploymentService service = (TrackerDeploymentService) controller.getValue();
        context.getResult().set(service.isShowCool());
    } else {
        context.getResult().set(TrackerSubsystemDefinition.SHOW_COOL_DEPLOYMENTS.getDefaultValue());
    }
}

完整实现代码参照 TrackerShowCoolReadHandler.java

TrackerShowCoolWriteHandler 继承了抽象类 AbstractWriteAttributeHandler，它主要功能是从属性 DMR 模型中读取输入值，设定读取值给TrackerDeploymentService:

if (attributeName.equals(TrackerSubsystemDefinition.SHOW_COOL)){
    TrackerDeploymentService service = (TrackerDeploymentService) context.getServiceRegistry(true).getRequiredService(TrackerDeploymentService.NAME).getValue();
    service.setShowCool(resolvedValue.asBoolean());
    context.getResult().set(true);
    context.completeStep(RollbackHandler.NOOP_ROLLBACK_HANDLER);
}

完整实现代码参照 TrackerShowCoolReadHandler.java

二级 type 节点有一个属性 tick，它代表 Tracker 的时间间隔，通过管理命令行可以进行读写操作

/subsystem=tracker/type=war:read-attribute(name=tick)
/subsystem=tracker/type=war:write-attribute(name=tick,value=20000)

读写操作是通过属性的 TypeTickReadHandler 和 TypeTickWriteHandler 实现的, TypeTickReadHandler 实现了接口 OperationStepHandler，它主要功能是从 TrackerService 中读取 tick 变量的值并设定给返回结果:

final String suffix = PathAddress.pathAddress(operation.get(ModelDescriptionConstants.ADDRESS)).getLastElement().getValue();
ServiceName serviceName = TrackerService.createServiceName(suffix);
ServiceController<?> controller = context.getServiceRegistry(true).getService(serviceName);
if(controller != null) {
    TrackerService service = (TrackerService)controller.getValue();
    context.getResult().set(service.getTick());
}

完整实现代码参照 TypeTickReadHandler.java

TypeTickWriteHandler 继承了抽象类 AbstractWriteAttributeHandler，它主要功能是从属性 DMR 模型中读取输入值，设定读取值给TrackerService:

final String suffix = PathAddress.pathAddress(operation.get(ModelDescriptionConstants.ADDRESS)).getLastElement().getValue();
TrackerService service = (TrackerService) context.getServiceRegistry(true).getRequiredService(TrackerService.createServiceName(suffix)).getValue();
service.setTick(resolvedValue.asLong());

完整实现代码参照 TypeTickWriteHandler.java

节点操作处理器实现

root 节点(Subsystem) 定义了一个 disable-all-tracker 操作，二级 type 节点定义了两个操作: disable-tracker 和 enable-tracker，通过管理命令行可以执行操作

/subsystem=tracker:disable-all-tracker()
/subsystem=tracker:list-deployments()
/subsystem=tracker:list-cool-deployments()
/subsystem=tracker/type=war:disable-tracker()
/subsystem=tracker/type=war:enable-tracker()

这些操作的执行分别通过操作处理器 TrackerDisableAllHandler, TrackerListAllHandler, TrackerListCoolHandler, TypeDisableHandler, TypeEnableHandler 来完成的。

TrackerDisableAllHandler

TrackerDisableAllHandler 实现了接口 OperationStepHandler，它主要功能是将 TrackerDeploymentService 的 showcool 变量设置为 false:

TrackerDeploymentService service = (TrackerDeploymentService) context.getServiceRegistry(true).getRequiredService(TrackerDeploymentService.NAME).getValue();
service.setShowCool(false);

完整实现代码参照 TrackerDisableAllHandler.java

TrackerListAllHandler

TrackerListAllHandler 实现了接口 OperationStepHandler，它主要功能是列出所有部署文件:

TrackerDeploymentService service = (TrackerDeploymentService) context.getServiceRegistry(true).getRequiredService(TrackerDeploymentService.NAME).getValue();
        Set<String> deployments = service.getDeployments();
        final ModelNode result = new ModelNode();
        if(deployments.isEmpty()){
            result.setEmptyList();
        } else {
            for(String deployment : deployments) {
                result.add(deployment);
            }
        }
        context.getResult().set(result);

完整实现代码参照 TrackerListAllHandler.java

TrackerListCoolHandler

TrackerListCoolHandler 实现了接口 OperationStepHandler，它主要功能是列出所有部署文件:

TrackerDeploymentService service = (TrackerDeploymentService) context.getServiceRegistry(true).getRequiredService(TrackerDeploymentService.NAME).getValue();
        Set<String> deployments = service.getCoolDeployments();
        final ModelNode result = new ModelNode();
        if(deployments.isEmpty()){
            result.setEmptyList();
        } else {
            for(String deployment : deployments) {
                result.add(deployment);
            }
        }
        context.getResult().set(result);

完整实现代码参照 TrackerListCoolHandler.java

TypeDisableHandler

TypeDisableHandler 实现了接口 OperationStepHandler，它主要功能是将 TrackerService 的 showcool 变量设置为 false:

final String suffix = PathAddress.pathAddress(operation.get(ModelDescriptionConstants.ADDRESS)).getLastElement().getValue();
TrackerService service = (TrackerService) context.getServiceRegistry(true).getRequiredService(TrackerService.createServiceName(suffix)).getValue();
service.setShowCool(false);

完整实现代码参照 TypeDisableHandler.java

TypeEnableHandler

TypeEnableHandler 实现了接口 OperationStepHandler，它主要功能是将 TrackerService 的 showcool 变量设置为 true:

final String suffix = PathAddress.pathAddress(operation.get(ModelDescriptionConstants.ADDRESS)).getLastElement().getValue();
TrackerService service = (TrackerService) context.getServiceRegistry(true).getRequiredService(TrackerService.createServiceName(suffix)).getValue();
service.setShowCool(true);

完整实现代码参照 TypeEnableHandler.java