ExponentialBackOffPolicy

java.lang.Object
- org.springframework.retry.backoff.ExponentialBackOffPolicy

All Implemented Interfaces:

BackOffPolicy, SleepingBackOffPolicy<ExponentialBackOffPolicy>

Direct Known Subclasses:

ExponentialRandomBackOffPolicy
```
public class ExponentialBackOffPolicy
extends java.lang.Object
implements SleepingBackOffPolicy<ExponentialBackOffPolicy>
```
Implementation of BackOffPolicy that increases the back off period for each retry attempt in a given set using the exponential function.
This implementation is thread-safe and suitable for concurrent access. Modifications to the configuration do not affect any retry sets that are already in progress.
The setInitialInterval(long) property controls the initial value passed to Math.exp(double) and the setMultiplier(double) property controls by how much this value is increased for each subsequent attempt.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

(package private) static class ExponentialBackOffPolicy.ExponentialBackOffContext

Nested Classes
Modifier and Type	Class and Description
`(package private) static class`	`ExponentialBackOffPolicy.ExponentialBackOffContext`

Field Summary

Fields
Modifier and Type	Field and Description
`static long`	`DEFAULT_INITIAL_INTERVAL` The default 'initialInterval' value - 100 millisecs.
`static long`	`DEFAULT_MAX_INTERVAL` The default maximum backoff time (30 seconds).
`static double`	`DEFAULT_MULTIPLIER` The default 'multiplier' value - value 2 (100% increase per backoff).
`private long`	`initialInterval` The initial sleep interval.
`protected org.apache.commons.logging.Log`	`logger`
`private long`	`maxInterval` The maximum value of the backoff period in milliseconds.
`private double`	`multiplier` The value to increment the exp seed with for each retry attempt.
`private Sleeper`	`sleeper`

Constructor Summary

Constructors
Constructor and Description

ExponentialBackOffPolicy()

Constructors
Constructor and Description
`ExponentialBackOffPolicy()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`backOff(BackOffContext backOffContext)` Pause for a length of time equal to ' `exp(backOffContext.expSeed)`'.
`protected void`	`cloneValues(ExponentialBackOffPolicy target)`
`long`	`getInitialInterval()` The initial period to sleep on the first backoff.
`long`	`getMaxInterval()` The maximum interval to sleep for.
`double`	`getMultiplier()` The multiplier to use to generate the next backoff interval from the last.
`protected ExponentialBackOffPolicy`	`newInstance()`
`void`	`setInitialInterval(long initialInterval)` Set the initial sleep interval value.
`void`	`setMaxInterval(long maxInterval)` Setter for maximum back off period.
`void`	`setMultiplier(double multiplier)` Set the multiplier value.
`void`	`setSleeper(Sleeper sleeper)` Public setter for the `Sleeper` strategy.
`BackOffContext`	`start(RetryContext context)` Returns a new instance of `BackOffContext` configured with the 'expSeed' and 'increment' values.
`java.lang.String`	`toString()`
`ExponentialBackOffPolicy`	`withSleeper(Sleeper sleeper)` Clone the policy and return a new policy which uses the passed sleeper.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - logger
```
protected final org.apache.commons.logging.Log logger
```
  - DEFAULT_INITIAL_INTERVAL
```
public static final long DEFAULT_INITIAL_INTERVAL
```
    The default 'initialInterval' value - 100 millisecs. Coupled with the default 'multiplier' value this gives a useful initial spread of pauses for 1-5 retries.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_MAX_INTERVAL
```
public static final long DEFAULT_MAX_INTERVAL
```
    The default maximum backoff time (30 seconds).
    
    See Also:
    
    Constant Field Values
  - DEFAULT_MULTIPLIER
```
public static final double DEFAULT_MULTIPLIER
```
    The default 'multiplier' value - value 2 (100% increase per backoff).
    
    See Also:
    
    Constant Field Values
  - initialInterval
```
private volatile long initialInterval
```
    The initial sleep interval.
  - maxInterval
```
private volatile long maxInterval
```
    The maximum value of the backoff period in milliseconds.
  - multiplier
```
private volatile double multiplier
```
    The value to increment the exp seed with for each retry attempt.
  - sleeper
```
private Sleeper sleeper
```
- Constructor Detail
  - ExponentialBackOffPolicy
```
public ExponentialBackOffPolicy()
```
- Method Detail
  - setSleeper
```
public void setSleeper(Sleeper sleeper)
```
    Public setter for the Sleeper strategy.
    
    Parameters:
    
    sleeper - the sleeper to set defaults to ThreadWaitSleeper.
  - withSleeper
```
public ExponentialBackOffPolicy withSleeper(Sleeper sleeper)
```
    Description copied from interface: SleepingBackOffPolicy
    
    Clone the policy and return a new policy which uses the passed sleeper.
    
    Specified by:
    
    withSleeper in interface SleepingBackOffPolicy<ExponentialBackOffPolicy>
    
    Parameters:
    
    sleeper - Target to be invoked any time the backoff policy sleeps
    
    Returns:
    
    a clone of this policy which will have all of its backoff sleeps routed into the passed sleeper
  - newInstance
```
protected ExponentialBackOffPolicy newInstance()
```
  - cloneValues
```
protected void cloneValues(ExponentialBackOffPolicy target)
```
  - setInitialInterval
```
public void setInitialInterval(long initialInterval)
```
    Set the initial sleep interval value. Default is 100 millisecond. Cannot be set to a value less than one.
  - setMultiplier
```
public void setMultiplier(double multiplier)
```
    Set the multiplier value. Default is '2.0'. Hint: do not use values much in excess of 1.0 (or the backoff will get very long very fast).
  - setMaxInterval
```
public void setMaxInterval(long maxInterval)
```
    Setter for maximum back off period. Default is 30000 (30 seconds). the value will be reset to 1 if this method is called with a value less than 1. Set this to avoid infinite waits if backing off a large number of times (or if the multiplier is set too high).
    
    Parameters:
    
    maxInterval - in milliseconds.
  - getInitialInterval
```
public long getInitialInterval()
```
    The initial period to sleep on the first backoff.
    
    Returns:
    
    the initial interval
  - getMaxInterval
```
public long getMaxInterval()
```
    The maximum interval to sleep for. Defaults to 30 seconds.
    
    Returns:
    
    the maximum interval.
  - getMultiplier
```
public double getMultiplier()
```
    The multiplier to use to generate the next backoff interval from the last.
    
    Returns:
    
    the multiplier in use
  - start
```
public BackOffContext start(RetryContext context)
```
    Returns a new instance of BackOffContext configured with the 'expSeed' and 'increment' values.
    
    Specified by:
    
    start in interface BackOffPolicy
    
    Parameters:
    
    context - the current retry context, which might contain information that we can use to decide how to proceed.
    
    Returns:
    
    the implementation-specific BackOffContext or 'null'.
  - backOff
```
public void backOff(BackOffContext backOffContext)
             throws BackOffInterruptedException
```
    Pause for a length of time equal to ' exp(backOffContext.expSeed)'.
    
    Specified by:
    
    backOff in interface BackOffPolicy
    
    Throws:
    
    BackOffInterruptedException - if the attempt at back off is interrupted.
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object

Class ExponentialBackOffPolicy

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

logger

DEFAULT_INITIAL_INTERVAL

DEFAULT_MAX_INTERVAL

DEFAULT_MULTIPLIER

initialInterval

maxInterval

multiplier

sleeper

Constructor Detail

ExponentialBackOffPolicy

Method Detail

setSleeper

withSleeper

newInstance

cloneValues

setInitialInterval

setMultiplier

setMaxInterval

getInitialInterval

getMaxInterval

getMultiplier

start

backOff

toString