ExponentialBackOff

java.lang.Object
- org.springframework.util.backoff.ExponentialBackOff

All Implemented Interfaces:

BackOff
```
public class ExponentialBackOff
extends java.lang.Object
implements BackOff
```
Implementation of BackOff that increases the back off period for each retry attempt. When the interval has reached the max interval, it is no longer increased. Stops retrying once the max elapsed time has been reached.
Example: The default interval is 2000L ms, the default multiplier is 1.5, and the default max interval is 30000L. For 10 attempts the sequence will be as follows:
```
 request#     back off

  1              2000
  2              3000
  3              4500
  4              6750
  5             10125
  6             15187
  7             22780
  8             30000
  9             30000
 10             30000
 
```
Note that the default max elapsed time is Long.MAX_VALUE. Use setMaxElapsedTime(long) to limit the maximum length of time that an instance should accumulate before returning BackOffExecution.STOP.
Since:

4.1

Author:

Stephane Nicoll

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

private class ExponentialBackOff.ExponentialBackOffExecution

Nested Classes
Modifier and Type	Class and Description
`private class`	`ExponentialBackOff.ExponentialBackOffExecution`

Field Summary

Fields
Modifier and Type	Field and Description
`static long`	`DEFAULT_INITIAL_INTERVAL` The default initial interval.
`static long`	`DEFAULT_MAX_ELAPSED_TIME` The default maximum elapsed time.
`static long`	`DEFAULT_MAX_INTERVAL` The default maximum back off time.
`static double`	`DEFAULT_MULTIPLIER` The default multiplier (increases the interval by 50%).
`private long`	`initialInterval`
`private long`	`maxElapsedTime`
`private long`	`maxInterval`
`private double`	`multiplier`

Constructor Summary

Constructors
Constructor and Description
`ExponentialBackOff()` Create an instance with the default settings.
`ExponentialBackOff(long initialInterval, double multiplier)` Create an instance with the supplied settings.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`private void`	`checkMultiplier(double multiplier)`
`long`	`getInitialInterval()` Return the initial interval in milliseconds.
`long`	`getMaxElapsedTime()` Return the maximum elapsed time in milliseconds after which a call to `BackOffExecution.nextBackOff()` returns `BackOffExecution.STOP`.
`long`	`getMaxInterval()` Return the maximum back off time.
`double`	`getMultiplier()` Return the value to multiply the current interval by for each retry attempt.
`void`	`setInitialInterval(long initialInterval)` The initial interval in milliseconds.
`void`	`setMaxElapsedTime(long maxElapsedTime)` The maximum elapsed time in milliseconds after which a call to `BackOffExecution.nextBackOff()` returns `BackOffExecution.STOP`.
`void`	`setMaxInterval(long maxInterval)` The maximum back off time.
`void`	`setMultiplier(double multiplier)` The value to multiply the current interval by for each retry attempt.
`BackOffExecution`	`start()` Start a new back off execution.

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

- Field Detail
  - DEFAULT_INITIAL_INTERVAL
```
public static final long DEFAULT_INITIAL_INTERVAL
```
    The default initial interval.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_MULTIPLIER
```
public static final double DEFAULT_MULTIPLIER
```
    The default multiplier (increases the interval by 50%).
    
    See Also:
    
    Constant Field Values
  - DEFAULT_MAX_INTERVAL
```
public static final long DEFAULT_MAX_INTERVAL
```
    The default maximum back off time.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_MAX_ELAPSED_TIME
```
public static final long DEFAULT_MAX_ELAPSED_TIME
```
    The default maximum elapsed time.
    
    See Also:
    
    Constant Field Values
  - initialInterval
```
private long initialInterval
```
  - multiplier
```
private double multiplier
```
  - maxInterval
```
private long maxInterval
```
  - maxElapsedTime
```
private long maxElapsedTime
```
- Constructor Detail
  - ExponentialBackOff
```
public ExponentialBackOff()
```
    Create an instance with the default settings.
    
    See Also:
    
    DEFAULT_INITIAL_INTERVAL, DEFAULT_MULTIPLIER, DEFAULT_MAX_INTERVAL, DEFAULT_MAX_ELAPSED_TIME
  - ExponentialBackOff
```
public ExponentialBackOff(long initialInterval,
                          double multiplier)
```
    Create an instance with the supplied settings.
    
    Parameters:
    
    initialInterval - the initial interval in milliseconds
    
    multiplier - the multiplier (should be greater than or equal to 1)
- Method Detail
  - setInitialInterval
```
public void setInitialInterval(long initialInterval)
```
    The initial interval in milliseconds.
  - getInitialInterval
```
public long getInitialInterval()
```
    Return the initial interval in milliseconds.
  - setMultiplier
```
public void setMultiplier(double multiplier)
```
    The value to multiply the current interval by for each retry attempt.
  - getMultiplier
```
public double getMultiplier()
```
    Return the value to multiply the current interval by for each retry attempt.
  - setMaxInterval
```
public void setMaxInterval(long maxInterval)
```
    The maximum back off time.
  - getMaxInterval
```
public long getMaxInterval()
```
    Return the maximum back off time.
  - setMaxElapsedTime
```
public void setMaxElapsedTime(long maxElapsedTime)
```
    The maximum elapsed time in milliseconds after which a call to BackOffExecution.nextBackOff() returns BackOffExecution.STOP.
  - getMaxElapsedTime
```
public long getMaxElapsedTime()
```
    Return the maximum elapsed time in milliseconds after which a call to BackOffExecution.nextBackOff() returns BackOffExecution.STOP.
  - start
```
public BackOffExecution start()
```
    Description copied from interface: BackOff
    
    Start a new back off execution.
    
    Specified by:
    
    start in interface BackOff
    
    Returns:
    
    a fresh BackOffExecution ready to be used
  - checkMultiplier
```
private void checkMultiplier(double multiplier)
```

Class ExponentialBackOff

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_INITIAL_INTERVAL

DEFAULT_MULTIPLIER

DEFAULT_MAX_INTERVAL

DEFAULT_MAX_ELAPSED_TIME

initialInterval

multiplier

maxInterval

maxElapsedTime

Constructor Detail

ExponentialBackOff

ExponentialBackOff

Method Detail

setInitialInterval

getInitialInterval

setMultiplier

getMultiplier

setMaxInterval

getMaxInterval

setMaxElapsedTime

getMaxElapsedTime

start

checkMultiplier