de.ipcon.schema

Class DefaultBreadcrumbFinder<T extends BreadcrumbContextI<T,U>,U extends BOI>

java.lang.Object

de.ipcon.schema.DefaultBreadcrumbFinder<T,U>

Type Parameters:

T - The type of the initial context object, which must implement BreadcrumbContextI.

U - The base type of the business object.

All Implemented Interfaces:

BreadcrumbFinderI<U>

public class DefaultBreadcrumbFinder<T extends BreadcrumbContextI<T,U>,U extends BOI>
extends java.lang.Object
implements BreadcrumbFinderI<U>

A concrete finder class that provides a starting point for a breadcrumb search. It holds the initial context and delegates the find operations to it.

This class serves as a public-facing facade, allowing clients to perform searches without knowing the internal details of the BreadcrumbContextI implementation.

Constructor Summary

Constructors

Constructor and Description
DefaultBreadcrumbFinder(T startContext) Creates a new finder instance for a specific starting context.

Method Summary

Modifier and Type	Method and Description
boolean	clearContext(T forContext) Clears the starting context for this finder instance, if it matches the passed context.
java.util.Optional<U>	findFirst() Returns the first business object found by walking up the chain from the initial context.
U	findFirstBO() Returns the first business object found by walking up the chain from the initial context, returning the value directly.
<V extends U> V	findFirstBOOfType(java.lang.Class<V> objectType) Returns the first business object of a specific type found in the parent chain, returning the value directly.
U	findFirstBOWhere(java.util.function.Predicate<U> predicate) Returns the first business object that matches the given predicate, found in the parent chain, returning the value directly.
<V extends U> java.util.Optional<V>	findFirstOfType(java.lang.Class<V> objectType) Returns the first business object of a specific type found in the parent chain.
java.util.Optional<U>	findFirstWhere(java.util.function.Predicate<U> predicate) Returns the first business object that matches the given predicate, found in the parent chain.
java.util.Optional<U>	findParent() Returns the business object of the immediate parent of the initial context.
U	findParentBO() Returns the business object of the immediate parent of the initial context, returning the value directly.
boolean	isEmpty() Determines if this finder instance is empty, i.e. it has no context yet.
boolean	setContextIfEmpty(T newContext) Sets the starting context for this finder instance only if the context is currently empty.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultBreadcrumbFinder

public DefaultBreadcrumbFinder(T startContext)

Creates a new finder instance for a specific starting context.

Parameters:

startContext - The context from which the search should begin.

Method Detail

setContextIfEmpty

public boolean setContextIfEmpty(T newContext)

Sets the starting context for this finder instance only if the context is currently empty.

This method is designed to be called when entering a new breadcrumb context. It prevents overwriting an existing context, which is crucial for nested accessor calls, as only the initial starting point in the structure shall be the starting point of the breadcrumb navigation. It also keeps a count of how many times a given context has been set to support nested calls where the same context instance is entered multiple times.

If the context is successfully set, this method also updates the thread-local finder in the Breadcrumb convenience class to allow easy access from static contexts.

Parameters:

newContext - The new context from which to begin a search.

Returns:

true if the context was successfully set; false if the context was already set.

clearContext

public boolean clearContext(T forContext)

Clears the starting context for this finder instance, if it matches the passed context.

This method uses an internal counter to handle nested set/clear calls for the same context. The context is only truly cleared, and the thread-local finder is removed, on the final call that matches the initial set call, preventing premature clearing in nested scenarios.

Parameters:

forContext - The context to compare against our internal start context.

Returns:

true if the starting context was cleared; false otherwise.

isEmpty

public boolean isEmpty()

Determines if this finder instance is empty, i.e. it has no context yet.

Returns:

true if the starting context is null; false otherwise.

findParent

public java.util.Optional<U> findParent()

Returns the business object of the immediate parent of the initial context.

Specified by:

findParent in interface BreadcrumbFinderI<U extends BOI>

Returns:

An Optional containing the parent's business object, or empty if not found.

findFirst

public java.util.Optional<U> findFirst()

Returns the first business object found by walking up the chain from the initial context.

Specified by:

findFirst in interface BreadcrumbFinderI<U extends BOI>

Returns:

An Optional containing the first found business object, or empty if not found.

findFirstOfType

public <V extends U> java.util.Optional<V> findFirstOfType(java.lang.Class<V> objectType)

Returns the first business object of a specific type found in the parent chain.

Specified by:

findFirstOfType in interface BreadcrumbFinderI<U extends BOI>

Type Parameters:

V - The specific type of the object.

Parameters:

objectType - The Class of the business object to find.

Returns:

An Optional containing the first found business object of the specified type.

findFirstWhere

public java.util.Optional<U> findFirstWhere(java.util.function.Predicate<U> predicate)

Returns the first business object that matches the given predicate, found in the parent chain.

Specified by:

findFirstWhere in interface BreadcrumbFinderI<U extends BOI>

Parameters:

predicate - The Predicate to test the business object.

Returns:

An Optional containing the first business object that satisfies the predicate.

findParentBO

public U findParentBO()

Returns the business object of the immediate parent of the initial context, returning the value directly.

Specified by:

findParentBO in interface BreadcrumbFinderI<U extends BOI>

Returns:

The parent's business object, or null if not found.

findFirstBO

public U findFirstBO()

Returns the first business object found by walking up the chain from the initial context, returning the value directly.

Specified by:

findFirstBO in interface BreadcrumbFinderI<U extends BOI>

Returns:

The first found business object, or null if not found.

findFirstBOOfType

public <V extends U> V findFirstBOOfType(java.lang.Class<V> objectType)

Returns the first business object of a specific type found in the parent chain, returning the value directly.

Specified by:

findFirstBOOfType in interface BreadcrumbFinderI<U extends BOI>

Type Parameters:

V - The specific type of the object.

Parameters:

objectType - The Class of the business object to find.

Returns:

The first found business object of the specified type, or null if not found.

findFirstBOWhere

public U findFirstBOWhere(java.util.function.Predicate<U> predicate)

Returns the first business object that matches the given predicate, found in the parent chain, returning the value directly.

Specified by:

findFirstBOWhere in interface BreadcrumbFinderI<U extends BOI>

Parameters:

predicate - The Predicate to test the business object.

Returns:

The first business object that satisfies the predicate, or null if not found.