Class ValueInstantiator
- java.lang.Object
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- com.fasterxml.jackson.databind.deser.ValueInstantiator
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- Direct Known Subclasses:
StdValueInstantiator
,ValueInstantiator.Base
,ValueInstantiator.Delegating
public abstract class ValueInstantiator extends java.lang.Object
Class that defines simple API implemented by objects that create value instances. Some or all of properties of value instances may be initialized by instantiator, rest being populated by deserializer, to which value instance is passed. Since different kinds of JSON values (structured and scalar) may be bound to Java values, in some cases instantiator fully defines resulting value; this is the case when JSON value is a scalar value (String, number, boolean).Note that this type is not parameterized (even though it would seemingly make sense), because such type information cannot be use effectively during runtime: access is always using either wildcard type, or just basic
Object
; and so adding type parameter seems like unnecessary extra work.Actual implementations are strongly recommended to be based on
StdValueInstantiator
which implements all methods, and as such will be compatible across versions even if new methods were added to this interface.
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
ValueInstantiator.Base
PartialValueInstantiator
implementation that is strongly recommended to be used instead of directly extendingValueInstantiator
itself.static class
ValueInstantiator.Delegating
DelegatingValueInstantiator
implementation meant as a base type that by default delegates methods to specified fallback instantiator.static interface
ValueInstantiator.Gettable
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Constructor Summary
Constructors Constructor Description ValueInstantiator()
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
canCreateFromBigDecimal()
Method that can be called to check whether a BigDecimal based creator is available to use (to callcreateFromBigDecimal(com.fasterxml.jackson.databind.DeserializationContext, java.math.BigDecimal)
).boolean
canCreateFromBigInteger()
Method that can be called to check whether a BigInteger based creator is available to use (to callcreateFromBigInteger(com.fasterxml.jackson.databind.DeserializationContext, java.math.BigInteger)
).boolean
canCreateFromBoolean()
Method that can be called to check whether a double (boolean / Boolean) based creator is available to use (to callcreateFromDouble(com.fasterxml.jackson.databind.DeserializationContext, double)
).boolean
canCreateFromDouble()
Method that can be called to check whether a double (double / Double) based creator is available to use (to callcreateFromDouble(com.fasterxml.jackson.databind.DeserializationContext, double)
).boolean
canCreateFromInt()
Method that can be called to check whether an integer (int, Integer) based creator is available to use (to callcreateFromInt(com.fasterxml.jackson.databind.DeserializationContext, int)
).boolean
canCreateFromLong()
Method that can be called to check whether a long (long, Long) based creator is available to use (to callcreateFromLong(com.fasterxml.jackson.databind.DeserializationContext, long)
).boolean
canCreateFromObjectWith()
Method that can be called to check whether a property-based creator (argument-taking constructor or factory method) is available to instantiate values from JSON Objectboolean
canCreateFromString()
Method that can be called to check whether a String-based creator is available for this instantiator.boolean
canCreateUsingArrayDelegate()
Method that can be called to check whether a array-delegate-based creator (single-arg constructor or factory method) is available for this instantiatorboolean
canCreateUsingDefault()
Method that can be called to check whether a default creator (constructor, or no-arg static factory method) is available for this instantiatorboolean
canCreateUsingDelegate()
Method that can be called to check whether a delegate-based creator (single-arg constructor or factory method) is available for this instantiatorboolean
canInstantiate()
Method that will return true if any ofcanCreateXxx
method returns true: that is, if there is any way that an instance could be created.ValueInstantiator
createContextual(DeserializationContext ctxt, BeanDescription beanDesc)
"Contextualization" method that is called after construction but before first use, to allow instantiator access to context needed to possible resolve its dependencies.java.lang.Object
createFromBigDecimal(DeserializationContext ctxt, java.math.BigDecimal value)
java.lang.Object
createFromBigInteger(DeserializationContext ctxt, java.math.BigInteger value)
java.lang.Object
createFromBoolean(DeserializationContext ctxt, boolean value)
java.lang.Object
createFromDouble(DeserializationContext ctxt, double value)
java.lang.Object
createFromInt(DeserializationContext ctxt, int value)
java.lang.Object
createFromLong(DeserializationContext ctxt, long value)
java.lang.Object
createFromObjectWith(DeserializationContext ctxt, SettableBeanProperty[] props, PropertyValueBuffer buffer)
Method that delegates tocreateFromObjectWith(DeserializationContext, Object[])
by default, but can be overridden if the application should have customized behavior with respect to missing properties.java.lang.Object
createFromObjectWith(DeserializationContext ctxt, java.lang.Object[] args)
Method called to create value instance from JSON Object when instantiation arguments are passed; this is done, for example when passing information specified with "Creator" annotations.java.lang.Object
createFromString(DeserializationContext ctxt, java.lang.String value)
java.lang.Object
createUsingArrayDelegate(DeserializationContext ctxt, java.lang.Object delegate)
Method to called to create value instance from JSON Array using an intermediate "delegate" value to pass to createor methodjava.lang.Object
createUsingDefault(DeserializationContext ctxt)
Method called to create value instance from a JSON value when no data needs to passed to creator (constructor, factory method); typically this will call the default constructor of the value object.java.lang.Object
createUsingDelegate(DeserializationContext ctxt, java.lang.Object delegate)
Method to called to create value instance from JSON Object using an intermediate "delegate" value to pass to createor methodAnnotatedWithParams
getArrayDelegateCreator()
Method that can be called to try to access member (constructor, static factory method) that is used as the "array delegate creator".JavaType
getArrayDelegateType(DeserializationConfig config)
Method that can be used to determine what is the type of array delegate type to use, if any; if no delegates are used, will return null.AnnotatedWithParams
getDefaultCreator()
Method that can be called to try to access member (constructor, static factory method) that is used as the "default creator" (creator that is called without arguments; typically default [zero-argument] constructor of the type).AnnotatedWithParams
getDelegateCreator()
Method that can be called to try to access member (constructor, static factory method) that is used as the "delegate creator".JavaType
getDelegateType(DeserializationConfig config)
Method that can be used to determine what is the type of delegate type to use, if any; if no delegates are used, will return null.SettableBeanProperty[]
getFromObjectArguments(DeserializationConfig config)
Method called to determine types of instantiation arguments to use when creating instances with creator arguments (whencanCreateFromObjectWith()
returns true).java.lang.Class<?>
getValueClass()
Accessor for raw (type-erased) type of instances to create.java.lang.String
getValueTypeDesc()
Method that returns description of the value type this instantiator handles.AnnotatedWithParams
getWithArgsCreator()
Method that can be called to try to access member (constructor, static factory method) that is used as the "non-default creator" (constructor or factory method that takes one or more arguments).
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Method Detail
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createContextual
public ValueInstantiator createContextual(DeserializationContext ctxt, BeanDescription beanDesc) throws JsonMappingException
"Contextualization" method that is called after construction but before first use, to allow instantiator access to context needed to possible resolve its dependencies.- Parameters:
ctxt
- Currently active deserialization context: needed to (for example) resolvingTypeDeserializer
s.- Returns:
- This instance, if no change, or newly constructed instance
- Throws:
JsonMappingException
- If there are issues with contextualization- Since:
- 2.12
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getValueClass
public java.lang.Class<?> getValueClass()
Accessor for raw (type-erased) type of instances to create.NOTE: since this method has not existed since beginning of Jackson 2.0 series, default implementation will just return
Object.class
; implementations are expected to override it with real value.- Since:
- 2.8
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getValueTypeDesc
public java.lang.String getValueTypeDesc()
Method that returns description of the value type this instantiator handles. Used for error messages, diagnostics.
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canInstantiate
public boolean canInstantiate()
Method that will return true if any ofcanCreateXxx
method returns true: that is, if there is any way that an instance could be created.
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canCreateFromString
public boolean canCreateFromString()
Method that can be called to check whether a String-based creator is available for this instantiator.NOTE: does NOT include possible case of fallbacks, or coercion; only considers explicit creator.
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canCreateFromInt
public boolean canCreateFromInt()
Method that can be called to check whether an integer (int, Integer) based creator is available to use (to callcreateFromInt(com.fasterxml.jackson.databind.DeserializationContext, int)
).
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canCreateFromLong
public boolean canCreateFromLong()
Method that can be called to check whether a long (long, Long) based creator is available to use (to callcreateFromLong(com.fasterxml.jackson.databind.DeserializationContext, long)
).
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canCreateFromBigInteger
public boolean canCreateFromBigInteger()
Method that can be called to check whether a BigInteger based creator is available to use (to callcreateFromBigInteger(com.fasterxml.jackson.databind.DeserializationContext, java.math.BigInteger)
). +
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canCreateFromDouble
public boolean canCreateFromDouble()
Method that can be called to check whether a double (double / Double) based creator is available to use (to callcreateFromDouble(com.fasterxml.jackson.databind.DeserializationContext, double)
).
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canCreateFromBigDecimal
public boolean canCreateFromBigDecimal()
Method that can be called to check whether a BigDecimal based creator is available to use (to callcreateFromBigDecimal(com.fasterxml.jackson.databind.DeserializationContext, java.math.BigDecimal)
).
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canCreateFromBoolean
public boolean canCreateFromBoolean()
Method that can be called to check whether a double (boolean / Boolean) based creator is available to use (to callcreateFromDouble(com.fasterxml.jackson.databind.DeserializationContext, double)
).
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canCreateUsingDefault
public boolean canCreateUsingDefault()
Method that can be called to check whether a default creator (constructor, or no-arg static factory method) is available for this instantiator
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canCreateUsingDelegate
public boolean canCreateUsingDelegate()
Method that can be called to check whether a delegate-based creator (single-arg constructor or factory method) is available for this instantiator
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canCreateUsingArrayDelegate
public boolean canCreateUsingArrayDelegate()
Method that can be called to check whether a array-delegate-based creator (single-arg constructor or factory method) is available for this instantiator- Since:
- 2.7
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canCreateFromObjectWith
public boolean canCreateFromObjectWith()
Method that can be called to check whether a property-based creator (argument-taking constructor or factory method) is available to instantiate values from JSON Object
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getFromObjectArguments
public SettableBeanProperty[] getFromObjectArguments(DeserializationConfig config)
Method called to determine types of instantiation arguments to use when creating instances with creator arguments (whencanCreateFromObjectWith()
returns true). These arguments are bound from JSON, using specified property types to locate deserializers.NOTE: all properties will be of type
CreatorProperty
.
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getDelegateType
public JavaType getDelegateType(DeserializationConfig config)
Method that can be used to determine what is the type of delegate type to use, if any; if no delegates are used, will return null. If non-null type is returned, deserializer will bind JSON into specified type (using standard deserializer for that type), and pass that to instantiator.
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getArrayDelegateType
public JavaType getArrayDelegateType(DeserializationConfig config)
Method that can be used to determine what is the type of array delegate type to use, if any; if no delegates are used, will return null. If non-null type is returned, deserializer will bind JSON into specified type (using standard deserializer for that type), and pass that to instantiator.- Since:
- 2.7
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createUsingDefault
public java.lang.Object createUsingDefault(DeserializationContext ctxt) throws java.io.IOException
Method called to create value instance from a JSON value when no data needs to passed to creator (constructor, factory method); typically this will call the default constructor of the value object. It will only be used if more specific creator methods are not applicable; hence "default".This method is called if
getFromObjectArguments(com.fasterxml.jackson.databind.DeserializationConfig)
returns null or empty List.- Throws:
java.io.IOException
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createFromObjectWith
public java.lang.Object createFromObjectWith(DeserializationContext ctxt, java.lang.Object[] args) throws java.io.IOException
Method called to create value instance from JSON Object when instantiation arguments are passed; this is done, for example when passing information specified with "Creator" annotations.This method is called if
getFromObjectArguments(com.fasterxml.jackson.databind.DeserializationConfig)
returns a non-empty List of arguments.- Throws:
java.io.IOException
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createFromObjectWith
public java.lang.Object createFromObjectWith(DeserializationContext ctxt, SettableBeanProperty[] props, PropertyValueBuffer buffer) throws java.io.IOException
Method that delegates tocreateFromObjectWith(DeserializationContext, Object[])
by default, but can be overridden if the application should have customized behavior with respect to missing properties.The default implementation of this method uses
PropertyValueBuffer.getParameters(SettableBeanProperty[])
to read and validate all properties in bulk, possibly substituting defaults for missing properties or throwing exceptions for missing properties. An overridden implementation of this method could, for example, usePropertyValueBuffer.hasParameter(SettableBeanProperty)
andPropertyValueBuffer.getParameter(SettableBeanProperty)
to safely read the present properties only, and to have some other behavior for the missing properties.- Throws:
java.io.IOException
- Since:
- 2.8
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createUsingDelegate
public java.lang.Object createUsingDelegate(DeserializationContext ctxt, java.lang.Object delegate) throws java.io.IOException
Method to called to create value instance from JSON Object using an intermediate "delegate" value to pass to createor method- Throws:
java.io.IOException
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createUsingArrayDelegate
public java.lang.Object createUsingArrayDelegate(DeserializationContext ctxt, java.lang.Object delegate) throws java.io.IOException
Method to called to create value instance from JSON Array using an intermediate "delegate" value to pass to createor method- Throws:
java.io.IOException
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createFromString
public java.lang.Object createFromString(DeserializationContext ctxt, java.lang.String value) throws java.io.IOException
- Throws:
java.io.IOException
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createFromInt
public java.lang.Object createFromInt(DeserializationContext ctxt, int value) throws java.io.IOException
- Throws:
java.io.IOException
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createFromLong
public java.lang.Object createFromLong(DeserializationContext ctxt, long value) throws java.io.IOException
- Throws:
java.io.IOException
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createFromBigInteger
public java.lang.Object createFromBigInteger(DeserializationContext ctxt, java.math.BigInteger value) throws java.io.IOException
- Throws:
java.io.IOException
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createFromDouble
public java.lang.Object createFromDouble(DeserializationContext ctxt, double value) throws java.io.IOException
- Throws:
java.io.IOException
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createFromBigDecimal
public java.lang.Object createFromBigDecimal(DeserializationContext ctxt, java.math.BigDecimal value) throws java.io.IOException
- Throws:
java.io.IOException
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createFromBoolean
public java.lang.Object createFromBoolean(DeserializationContext ctxt, boolean value) throws java.io.IOException
- Throws:
java.io.IOException
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getDefaultCreator
public AnnotatedWithParams getDefaultCreator()
Method that can be called to try to access member (constructor, static factory method) that is used as the "default creator" (creator that is called without arguments; typically default [zero-argument] constructor of the type). Note that implementations not required to return actual object they use (or, they may use some other instantiation) method. That is, even ifcanCreateUsingDefault()
returns true, this method may return null .
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getDelegateCreator
public AnnotatedWithParams getDelegateCreator()
Method that can be called to try to access member (constructor, static factory method) that is used as the "delegate creator". Note that implementations not required to return actual object they use (or, they may use some other instantiation) method. That is, even ifcanCreateUsingDelegate()
returns true, this method may return null .
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getArrayDelegateCreator
public AnnotatedWithParams getArrayDelegateCreator()
Method that can be called to try to access member (constructor, static factory method) that is used as the "array delegate creator". Note that implementations not required to return actual object they use (or, they may use some other instantiation) method. That is, even ifcanCreateUsingArrayDelegate()
returns true, this method may return null .
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getWithArgsCreator
public AnnotatedWithParams getWithArgsCreator()
Method that can be called to try to access member (constructor, static factory method) that is used as the "non-default creator" (constructor or factory method that takes one or more arguments). Note that implementations not required to return actual object they use (or, they may use some other instantiation) method. That is, even ifcanCreateFromObjectWith()
returns true, this method may return null .
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