com.netflix.hystrix.contrib.javanica.command

Class GenericCommand

java.lang.Object

com.netflix.hystrix.HystrixCommand<T>

com.netflix.hystrix.contrib.javanica.command.AbstractHystrixCommand<java.lang.Object>

com.netflix.hystrix.contrib.javanica.command.GenericCommand

All Implemented Interfaces:

com.netflix.hystrix.HystrixExecutable<java.lang.Object>, com.netflix.hystrix.HystrixInvokable<java.lang.Object>, com.netflix.hystrix.HystrixInvokableInfo<java.lang.Object>, com.netflix.hystrix.HystrixObservable<java.lang.Object>

@ThreadSafe
public class GenericCommand
extends AbstractHystrixCommand<java.lang.Object>

Implementation of AbstractHystrixCommand which returns an Object as result.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	com.netflix.hystrix.AbstractCommand.CommandState
protected static class	com.netflix.hystrix.AbstractCommand.ThreadState
protected static class	com.netflix.hystrix.AbstractCommand.TimedOutStatus

Nested classes/interfaces inherited from class com.netflix.hystrix.HystrixCommand

com.netflix.hystrix.HystrixCommand.Setter

Field Summary

Fields

Modifier and Type	Field and Description
protected com.netflix.hystrix.HystrixCircuitBreaker	circuitBreaker
protected static java.util.concurrent.ConcurrentHashMap<com.netflix.hystrix.HystrixCommandKey,java.lang.Boolean>	commandContainsFallback
protected com.netflix.hystrix.HystrixCommandGroupKey	commandGroup
protected com.netflix.hystrix.HystrixCommandKey	commandKey
protected long	commandStartTimestamp
protected java.util.concurrent.atomic.AtomicReference<com.netflix.hystrix.AbstractCommand.CommandState>	commandState
protected com.netflix.hystrix.strategy.concurrency.HystrixConcurrencyStrategy	concurrencyStrategy
protected com.netflix.hystrix.HystrixRequestLog	currentRequestLog
protected rx.functions.Action0	endCurrentThreadExecutingCommand
protected com.netflix.hystrix.strategy.eventnotifier.HystrixEventNotifier	eventNotifier
protected com.netflix.hystrix.strategy.executionhook.HystrixCommandExecutionHook	executionHook
protected com.netflix.hystrix.ExecutionResult	executionResult
protected com.netflix.hystrix.ExecutionResult	executionResultAtTimeOfCancellation
protected com.netflix.hystrix.AbstractCommand.TryableSemaphore	executionSemaphoreOverride
protected static java.util.concurrent.ConcurrentHashMap<java.lang.String,com.netflix.hystrix.AbstractCommand.TryableSemaphore>	executionSemaphorePerCircuit
protected com.netflix.hystrix.AbstractCommand.TryableSemaphore	fallbackSemaphoreOverride
protected static java.util.concurrent.ConcurrentHashMap<java.lang.String,com.netflix.hystrix.AbstractCommand.TryableSemaphore>	fallbackSemaphorePerCircuit
protected java.util.concurrent.atomic.AtomicReference<com.netflix.hystrix.AbstractCommand.TimedOutStatus>	isCommandTimedOut
protected boolean	isResponseFromCache
protected com.netflix.hystrix.HystrixCommandMetrics	metrics
protected com.netflix.hystrix.HystrixCommandProperties	properties
protected com.netflix.hystrix.HystrixRequestCache	requestCache
protected com.netflix.hystrix.HystrixThreadPool	threadPool
protected com.netflix.hystrix.HystrixThreadPoolKey	threadPoolKey
protected java.util.concurrent.atomic.AtomicReference<com.netflix.hystrix.AbstractCommand.ThreadState>	threadState
protected java.util.concurrent.atomic.AtomicReference<java.lang.ref.Reference<com.netflix.hystrix.util.HystrixTimer.TimerListener>>	timeoutTimer

Constructor Summary

Constructors

Constructor and Description
GenericCommand(HystrixCommandBuilder builder)

Method Summary

Modifier and Type	Method and Description
protected java.lang.Throwable	decomposeException(java.lang.Exception arg0)
protected java.lang.Exception	getExceptionFromThrowable(java.lang.Throwable arg0)
protected com.netflix.hystrix.AbstractCommand.TryableSemaphore	getExecutionSemaphore()
protected java.lang.Object	getFallback() The fallback is performed whenever a command execution fails.
protected com.netflix.hystrix.AbstractCommand.TryableSemaphore	getFallbackSemaphore()
protected java.lang.String	getLogMessagePrefix()
protected void	handleThreadEnd(com.netflix.hystrix.AbstractCommand<R> arg0)
protected boolean	isRequestCachingEnabled()
protected java.lang.Object	run() .
protected boolean	shouldNotBeWrapped(java.lang.Throwable arg0)
protected boolean	shouldOutputOnNextEvents()

Methods inherited from class com.netflix.hystrix.contrib.javanica.command.AbstractHystrixCommand

flushCache, getCacheKey, getCollapsedRequests, getCommandAction, getExecutionType, getFallbackAction, getIgnoreExceptions

Methods inherited from class com.netflix.hystrix.HystrixCommand

commandIsScalar, execute, getExecutionObservable, getFallbackMethodName, getFallbackObservable, isFallbackUserDefined, queue

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

circuitBreaker

protected final com.netflix.hystrix.HystrixCircuitBreaker circuitBreaker

threadPool

protected final com.netflix.hystrix.HystrixThreadPool threadPool

threadPoolKey

protected final com.netflix.hystrix.HystrixThreadPoolKey threadPoolKey

properties

protected final com.netflix.hystrix.HystrixCommandProperties properties

metrics

protected final com.netflix.hystrix.HystrixCommandMetrics metrics

commandKey

protected final com.netflix.hystrix.HystrixCommandKey commandKey

commandGroup

protected final com.netflix.hystrix.HystrixCommandGroupKey commandGroup

eventNotifier

protected final com.netflix.hystrix.strategy.eventnotifier.HystrixEventNotifier eventNotifier

concurrencyStrategy

protected final com.netflix.hystrix.strategy.concurrency.HystrixConcurrencyStrategy concurrencyStrategy

executionHook

protected final com.netflix.hystrix.strategy.executionhook.HystrixCommandExecutionHook executionHook

fallbackSemaphoreOverride

protected final com.netflix.hystrix.AbstractCommand.TryableSemaphore fallbackSemaphoreOverride

fallbackSemaphorePerCircuit

protected static final java.util.concurrent.ConcurrentHashMap<java.lang.String,com.netflix.hystrix.AbstractCommand.TryableSemaphore> fallbackSemaphorePerCircuit

executionSemaphoreOverride

protected final com.netflix.hystrix.AbstractCommand.TryableSemaphore executionSemaphoreOverride

executionSemaphorePerCircuit

protected static final java.util.concurrent.ConcurrentHashMap<java.lang.String,com.netflix.hystrix.AbstractCommand.TryableSemaphore> executionSemaphorePerCircuit

timeoutTimer

protected final java.util.concurrent.atomic.AtomicReference<java.lang.ref.Reference<com.netflix.hystrix.util.HystrixTimer.TimerListener>> timeoutTimer

commandState

protected java.util.concurrent.atomic.AtomicReference<com.netflix.hystrix.AbstractCommand.CommandState> commandState

threadState

protected java.util.concurrent.atomic.AtomicReference<com.netflix.hystrix.AbstractCommand.ThreadState> threadState

executionResult

protected volatile com.netflix.hystrix.ExecutionResult executionResult

isResponseFromCache

protected volatile boolean isResponseFromCache

executionResultAtTimeOfCancellation

protected volatile com.netflix.hystrix.ExecutionResult executionResultAtTimeOfCancellation

commandStartTimestamp

protected volatile long commandStartTimestamp

isCommandTimedOut

protected final java.util.concurrent.atomic.AtomicReference<com.netflix.hystrix.AbstractCommand.TimedOutStatus> isCommandTimedOut

endCurrentThreadExecutingCommand

protected volatile rx.functions.Action0 endCurrentThreadExecutingCommand

requestCache

protected final com.netflix.hystrix.HystrixRequestCache requestCache

currentRequestLog

protected final com.netflix.hystrix.HystrixRequestLog currentRequestLog

commandContainsFallback

protected static java.util.concurrent.ConcurrentHashMap<com.netflix.hystrix.HystrixCommandKey,java.lang.Boolean> commandContainsFallback

Constructor Detail

GenericCommand

public GenericCommand(HystrixCommandBuilder builder)

Method Detail

run

protected java.lang.Object run()
                        throws java.lang.Exception

.

Specified by:

run in class AbstractHystrixCommand<java.lang.Object>

Throws:

java.lang.Exception

getFallback

protected java.lang.Object getFallback()

The fallback is performed whenever a command execution fails. Also a fallback method will be invoked within separate command in the case if fallback method was annotated with HystrixCommand annotation, otherwise current implementation throws RuntimeException and leaves the caller to deal with it (see super#getFallback()). The getFallback() is always processed synchronously. Since getFallback() can throw only runtime exceptions thus any exceptions are thrown within getFallback() method are wrapped in FallbackInvocationException. A caller gets HystrixRuntimeException and should call getCause to get original exception that was thrown in getFallback().

Overrides:

getFallback in class AbstractHystrixCommand<java.lang.Object>

Returns:

result of invocation of fallback method or RuntimeException

shouldNotBeWrapped

protected boolean shouldNotBeWrapped(java.lang.Throwable arg0)

handleThreadEnd

protected void handleThreadEnd(com.netflix.hystrix.AbstractCommand<R> arg0)

shouldOutputOnNextEvents

protected boolean shouldOutputOnNextEvents()

getFallbackSemaphore

protected com.netflix.hystrix.AbstractCommand.TryableSemaphore getFallbackSemaphore()

getExecutionSemaphore

protected com.netflix.hystrix.AbstractCommand.TryableSemaphore getExecutionSemaphore()

decomposeException

protected java.lang.Throwable decomposeException(java.lang.Exception arg0)

isRequestCachingEnabled

protected boolean isRequestCachingEnabled()

getLogMessagePrefix

protected java.lang.String getLogMessagePrefix()

getExceptionFromThrowable

protected java.lang.Exception getExceptionFromThrowable(java.lang.Throwable arg0)