javax.validation.Path Maven / Gradle / Ivy
/*
* Bean Validation API
*
* License: Apache License, Version 2.0
* See the license.txt file in the root directory or .
*/
package javax.validation;
import java.util.List;
import javax.validation.valueextraction.ValueExtractor;
/**
* Represents the navigation path from an object to another
* in an object graph.
* Each path element is represented by a {@code Node}.
*
* The path corresponds to the succession of nodes
* in the order they are returned by the {@code Iterator}.
*
* @author Emmanuel Bernard
* @author Gunnar Morling
* @author Guillaume Smet
*/
public interface Path extends Iterable {
/**
* Returns a human-readable representation of this path.
*
* Clients should not rely on any specific structure of the returned value. Instead they
* should iterate through the path nodes and obtain any required information by calling
* the methods on {@link Node} and its sub-types.
*
* @return a human-readable representation of this path
* @since 2.0
*/
@Override
String toString();
/**
* Represents an element of a navigation path.
*/
interface Node {
/**
* Returns the name of the element which the node represents:
*
* - {@code null} if it is a leaf node which represents an entity / bean.
* In particular, the node representing the root object.
* - The property name for a property.
* - The method name for a method.
* - The unqualified name of the type declaring the constructor
* for a constructor.
* - The parameter named as defined by the {@link ParameterNameProvider}
* for a method or constructor parameter.
* - The literal {@code
} for a method or constructor
* cross-parameter.
* - The literal {@code
} for a method or constructor return
* value.
* - The node name as defined by the {@link ValueExtractor} for a container
* element; specifically, the literal {@code
} for elements
* stored in a list, the literal {@code } for elements
* stored in an {@code Iterable}, the literal {@code
*
* @return name of the element which the node represents
*/
String getName();
/**
* @return {@code true} if the node represents an object contained in
* a multi-valued container such as {@code Iterable} or {@code Map} or an array,
* {@code false} otherwise
*/
boolean isInIterable();
/**
* @return the index the node is placed in if contained in an array, a {@code List}
* or any other container supporting indexed access, {@code null} otherwise
*/
Integer getIndex();
/**
* @return the key the node is placed in if contained in a {@code Map} or any
* other container supporting keyed access, {@code null} otherwise
*/
Object getKey();
/**
* The kind of element represented by the node. The following relationship
* between an {@link ElementKind} and its {@code Node} subtype exists:
*
* - {@link ElementKind#BEAN}: {@link BeanNode}
* - {@link ElementKind#PROPERTY}: {@link PropertyNode}
* - {@link ElementKind#METHOD}: {@link MethodNode}
* - {@link ElementKind#CONSTRUCTOR}: {@link ConstructorNode}
* - {@link ElementKind#PARAMETER}: {@link ParameterNode}
* - {@link ElementKind#CROSS_PARAMETER}: {@link CrossParameterNode}
* - {@link ElementKind#RETURN_VALUE}: {@link ReturnValueNode}
* - {@link ElementKind#CONTAINER_ELEMENT}: {@link ContainerElementNode}
*
*
* This is useful to narrow down the {@code Node} type and access node specific
* information:
*
* switch(node.getKind() {
* case METHOD:
* name = node.getName();
* params = node.as(MethodNode.class).getParameterTypes();
* case PARAMETER:
* index = node.as(ParameterNode.class).getParameterIndex();
* [...]
* }
*
* @return the {@code ElementKind}
*
* @since 1.1
*/
ElementKind getKind();
/**
* Narrows the type of this node down to the given type. The appropriate
* type should be checked before by calling {@link #getKind()}.
*
* @param the type to narrow down to
* @param nodeType class object representing the descriptor type to narrow down to
* to
*
* @return this node narrowed down to the given type.
*
* @throws ClassCastException if this node is not assignable to the type {@code T}
* @since 1.1
*/
T as(Class nodeType);
/**
* Returns a human-readable representation of this node.
*
* Clients should not rely on any specific structure of the returned value. Instead
* they should obtain any required information by calling the methods on this
* interface and its sub-types.
*
* @return a human-readable representation of this node
* @since 2.0
*/
@Override
String toString();
}
/**
* Node representing a method.
*
* @since 1.1
*/
interface MethodNode extends Node {
/**
* @return the list of parameter types
*/
List> getParameterTypes();
}
/**
* Node representing a constructor.
*
* @since 1.1
*/
interface ConstructorNode extends Node {
/**
* @return the list of parameter types
*/
List> getParameterTypes();
}
/**
* Node representing the return value of a method or constructor.
*
* @since 1.1
*/
interface ReturnValueNode extends Node {
}
/**
* Node representing a parameter of a method or constructor.
*
* @since 1.1
*/
interface ParameterNode extends Node {
/**
* @return the parameter index in the method or constructor definition
*/
int getParameterIndex();
}
/**
* Node representing the element holding cross-parameter constraints
* of a method or constructor.
*
* @since 1.1
*/
interface CrossParameterNode extends Node {
}
/**
* Node representing a bean.
*
* @since 1.1
*/
interface BeanNode extends Node {
/**
* @return the type of the container the node is placed in, if contained in a
* container type such as {@code Optional}, {@code List} or {@code Map},
* {@code null} otherwise
*
* @since 2.0
*/
Class getContainerClass();
/**
* @return the index of the type argument affected by the violated constraint, if
* contained in a generic container type such as {@code Optional}, {@code List} or
* {@code Map}.
*
* @since 2.0
*/
Integer getTypeArgumentIndex();
}
/**
* Node representing a property.
*
* @since 1.1
*/
interface PropertyNode extends Node {
/**
* @return the type of the container the node is placed in, if contained in a
* container type such as {@code Optional}, {@code List} or {@code Map},
* {@code null} otherwise
*
* @since 2.0
*/
Class getContainerClass();
/**
* @return the index of the type argument affected by the violated constraint, if
* contained in a generic container type such as {@code Optional}, {@code List} or
* {@code Map}, {@code null} otherwise
*
* @since 2.0
*/
Integer getTypeArgumentIndex();
}
/**
* Node representing an element in a generic container such as {@code Optional},
* {@code List} or {@code Map}.
*
* @since 2.0
*/
interface ContainerElementNode extends Node {
/**
* @return the type of the container the node is placed in
*/
Class getContainerClass();
/**
* @return the index of the type argument affected by the violated constraint
*/
Integer getTypeArgumentIndex();
}
}