org.apache.hadoop.tools.distcp2.util

类 RetriableCommand

java.lang.Object

org.apache.hadoop.tools.distcp2.util.RetriableCommand

直接已知子类:

RetriableDirectoryCreateCommand, RetriableFileCopyCommand

public abstract class RetriableCommand
extends Object

This class represents commands that be retried on failure, in a configurable manner.

字段概要

字段

限定符和类型	字段和说明
protected String	description

构造器概要

构造器

构造器和说明
RetriableCommand(String description) Constructor.
RetriableCommand(String description, RetryPolicy retryPolicy) Constructor.

方法概要

方法

限定符和类型	方法和说明
protected abstract Object	doExecute(Object... arguments) Implement this interface-method define the command-logic that will be retried on failure (i.e. with Exception).
Object	execute(Object... arguments) The execute() method invokes doExecute() until either: 1. doExecute() succeeds, or 2. the command may no longer be retried (e.g. runs out of retry-attempts).
RetriableCommand	setRetryPolicy(RetryPolicy retryHandler) Fluent-interface to change the RetryHandler.

从类继承的方法 java.lang.Object

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

字段详细资料

description

protected String description

构造器详细资料

RetriableCommand

public RetriableCommand(String description)

Constructor.

参数:

description - The human-readable description of the command.

RetriableCommand

public RetriableCommand(String description,
                RetryPolicy retryPolicy)

Constructor.

参数:

description - The human-readable description of the command.

retryPolicy - The RetryHandler to be used to compute retries.

方法详细资料

doExecute

protected abstract Object doExecute(Object... arguments)
                             throws Exception

Implement this interface-method define the command-logic that will be retried on failure (i.e. with Exception).

参数:

arguments - Argument-list to the command.

返回:

Generic "Object".

抛出:

Exception - Throws Exception on complete failure.

execute

public Object execute(Object... arguments)
               throws Exception

The execute() method invokes doExecute() until either: 1. doExecute() succeeds, or 2. the command may no longer be retried (e.g. runs out of retry-attempts).

参数:

arguments - The list of arguments for the command.

返回:

Generic "Object" from doExecute(), on success.

抛出:

IOException, - IOException, on complete failure.

Exception

setRetryPolicy

public RetriableCommand setRetryPolicy(RetryPolicy retryHandler)

Fluent-interface to change the RetryHandler.

参数:

retryHandler - The new RetryHandler instance to be used.

返回:

Self.