io.github.resilience4j.fallback

Class FallbackMethod

java.lang.Object

io.github.resilience4j.fallback.FallbackMethod

public class FallbackMethod
extends java.lang.Object

Reflection utility for invoking a fallback method. Fallback method should have same return type and parameter types of original method but the last additional parameter. The last additional parameter should be a subclass of Throwable. When fallback(Throwable) is invoked, Throwable will be passed to that last parameter. If there are multiple fallback method, one of the methods that has most closest superclass parameter of thrown object will be invoked.

 For example, there are two fallback methods
 
 String fallbackMethod(String parameter, RuntimeException exception)
 String fallbackMethod(String parameter, IllegalArgumentException exception)
 
 and if try to fallback from NumberFormatException,  String fallbackMethod(String parameter, IllegalArgumentException exception) will be invoked.
 

Method Summary

Modifier and Type	Method and Description
static FallbackMethod	create(java.lang.String fallbackMethodName, java.lang.reflect.Method originalMethod, java.lang.Object[] args, java.lang.Object target)
java.lang.Object	fallback(java.lang.Throwable thrown) try to fallback from Throwable
java.lang.Class<?>	getReturnType() get return type of fallbackMethod method

Methods inherited from class java.lang.Object

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

Method Detail

create

public static FallbackMethod create(java.lang.String fallbackMethodName,
                                    java.lang.reflect.Method originalMethod,
                                    java.lang.Object[] args,
                                    java.lang.Object target)
                             throws java.lang.NoSuchMethodException

Parameters:

fallbackMethodName - the configured fallback method name

originalMethod - the original method which has fallback method configured

args - the original method arguments

target - the target class that own the original method and fallback method

Returns:

FallbackMethod instance

Throws:

java.lang.NoSuchMethodException

fallback

@Nullable
public java.lang.Object fallback(java.lang.Throwable thrown)
                                     throws java.lang.Throwable

try to fallback from Throwable

Parameters:

thrown - Throwable that should be fallback

Returns:

fallback value

Throws:

java.lang.Throwable - if throwable is unrecoverable, throwable will be thrown

getReturnType

public java.lang.Class<?> getReturnType()

get return type of fallbackMethod method

Returns:

return type of fallbackMethod method