org.springframework.boot.context.properties.bind

Interface BindHandler

All Known Implementing Classes:

AbstractBindHandler, IgnoreErrorsBindHandler, IgnoreTopLevelConverterNotFoundBindHandler, NoUnboundElementsBindHandler, ValidationBindHandler

public interface BindHandler

Callback interface that can be used to handle additional logic during element binding.

Since:

2.0.0

Author:

Phillip Webb, Madhura Bhave

Field Summary

Fields

Modifier and Type	Field and Description
static BindHandler	DEFAULT Default no-op bind handler.

Method Summary

Modifier and Type	Method and Description
default Object	onCreate(ConfigurationPropertyName name, Bindable<?> target, BindContext context, Object result) Called when binding of an element ends with an unbound result and a newly created instance is about to be returned.
default Object	onFailure(ConfigurationPropertyName name, Bindable<?> target, BindContext context, Exception error) Called when binding fails for any reason (including failures from onSuccess(org.springframework.boot.context.properties.source.ConfigurationPropertyName, org.springframework.boot.context.properties.bind.Bindable<?>, org.springframework.boot.context.properties.bind.BindContext, java.lang.Object) or onCreate(org.springframework.boot.context.properties.source.ConfigurationPropertyName, org.springframework.boot.context.properties.bind.Bindable<?>, org.springframework.boot.context.properties.bind.BindContext, java.lang.Object) calls).
default void	onFinish(ConfigurationPropertyName name, Bindable<?> target, BindContext context, Object result) Called when binding finishes with either bound or unbound result.
default <T> Bindable<T>	onStart(ConfigurationPropertyName name, Bindable<T> target, BindContext context) Called when binding of an element starts but before any result has been determined.
default Object	onSuccess(ConfigurationPropertyName name, Bindable<?> target, BindContext context, Object result) Called when binding of an element ends with a successful result.

Field Detail

DEFAULT

static final BindHandler DEFAULT

Default no-op bind handler.

Method Detail

onStart

default <T> Bindable<T> onStart(ConfigurationPropertyName name,
                                Bindable<T> target,
                                BindContext context)

Called when binding of an element starts but before any result has been determined.

Type Parameters:

T - the bindable source type

Parameters:

name - the name of the element being bound

target - the item being bound

context - the bind context

Returns:

the actual item that should be used for binding (may be null)

onSuccess

default Object onSuccess(ConfigurationPropertyName name,
                         Bindable<?> target,
                         BindContext context,
                         Object result)

Called when binding of an element ends with a successful result. Implementations may change the ultimately returned result or perform addition validation.

Parameters:

name - the name of the element being bound

target - the item being bound

context - the bind context

result - the bound result (never null)

Returns:

the actual result that should be used (may be null)

onCreate

default Object onCreate(ConfigurationPropertyName name,
                        Bindable<?> target,
                        BindContext context,
                        Object result)

Called when binding of an element ends with an unbound result and a newly created instance is about to be returned. Implementations may change the ultimately returned result or perform addition validation.

Parameters:

name - the name of the element being bound

target - the item being bound

context - the bind context

result - the newly created instance (never null)

Returns:

the actual result that should be used (must not be null)

Since:

2.2.2

onFailure

default Object onFailure(ConfigurationPropertyName name,
                         Bindable<?> target,
                         BindContext context,
                         Exception error)
                  throws Exception

Called when binding fails for any reason (including failures from onSuccess(org.springframework.boot.context.properties.source.ConfigurationPropertyName, org.springframework.boot.context.properties.bind.Bindable<?>, org.springframework.boot.context.properties.bind.BindContext, java.lang.Object) or onCreate(org.springframework.boot.context.properties.source.ConfigurationPropertyName, org.springframework.boot.context.properties.bind.Bindable<?>, org.springframework.boot.context.properties.bind.BindContext, java.lang.Object) calls). Implementations may choose to swallow exceptions and return an alternative result.

Parameters:

name - the name of the element being bound

target - the item being bound

context - the bind context

error - the cause of the error (if the exception stands it may be re-thrown)

Returns:

the actual result that should be used (may be null).

Throws:

Exception - if the binding isn't valid

onFinish

default void onFinish(ConfigurationPropertyName name,
                      Bindable<?> target,
                      BindContext context,
                      Object result)
               throws Exception

Called when binding finishes with either bound or unbound result. This method will not be called when binding failed, even if a handler returns a result from onFailure(org.springframework.boot.context.properties.source.ConfigurationPropertyName, org.springframework.boot.context.properties.bind.Bindable<?>, org.springframework.boot.context.properties.bind.BindContext, java.lang.Exception).

Parameters:

name - the name of the element being bound

target - the item being bound

context - the bind context

result - the bound result (may be null)

Throws:

Exception - if the binding isn't valid