Package org.codehaus.jackson.map.deser
Class ValueInstantiator
java.lang.Object
org.codehaus.jackson.map.deser.ValueInstantiator
- Direct Known Subclasses:
StdValueInstantiator
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 can not 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.
- Since:
- 1.9
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionboolean
Method that can be called to check whether a double (boolean / Boolean) based creator is available to use (to callcreateFromDouble(double)
).boolean
Method that can be called to check whether a double (double / Double) based creator is available to use (to callcreateFromDouble(double)
).boolean
Method that can be called to check whether an integer (int, Integer) based creator is available to use (to callcreateFromInt(int)
).boolean
Method that can be called to check whether a long (long, Long) based creator is available to use (to callcreateFromLong(long)
).boolean
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
Method that can be called to check whether a String-based creator is available for this instantiatorboolean
Method that can be called to check whether a default creator (constructor, or no-arg static factory method) is available for this instantiatorboolean
Method that can be called to check whether a delegate-based creator (single-arg constructor or factory method) is available for this instantiatorboolean
Method that will return true if any ofcanCreateXxx
method returns true: that is, if there is any way that an instance could be created.createFromBoolean
(boolean value) createFromDouble
(double value) createFromInt
(int value) createFromLong
(long value) createFromObjectWith
(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.createFromString
(String value) 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.createUsingDelegate
(Object delegate) Method to called to create value instance from JSON Object using an intermediate "delegate" value to pass to createor methodMethod 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).Method that can be called to try to access member (constructor, static factory method) that is used as the "delegate creator".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.Method called to determine types of instantiation arguments to use when creating instances with creator arguments (whencanCreateFromObjectWith()
returns true).abstract String
Method that returns description of the value type this instantiator handles.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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Constructor Details
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ValueInstantiator
public ValueInstantiator()
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Method Details
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getValueTypeDesc
Method that returns description of the value type this instantiator handles. Used for error messages, diagnostics. -
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. -
canCreateFromString
public boolean canCreateFromString()Method that can be called to check whether a String-based creator is available for this instantiator -
canCreateFromInt
public boolean canCreateFromInt()Method that can be called to check whether an integer (int, Integer) based creator is available to use (to callcreateFromInt(int)
). -
canCreateFromLong
public boolean canCreateFromLong()Method that can be called to check whether a long (long, Long) based creator is available to use (to callcreateFromLong(long)
). -
canCreateFromDouble
public boolean canCreateFromDouble()Method that can be called to check whether a double (double / Double) based creator is available to use (to callcreateFromDouble(double)
). -
canCreateFromBoolean
public boolean canCreateFromBoolean()Method that can be called to check whether a double (boolean / Boolean) based creator is available to use (to callcreateFromDouble(double)
). -
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 -
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 -
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 -
getFromObjectArguments
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
. -
getDelegateType
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. -
createUsingDefault
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()
returns null or empty List.- Throws:
IOException
JsonProcessingException
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createFromObjectWith
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()
returns a non-empty List of arguments.- Throws:
IOException
JsonProcessingException
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createUsingDelegate
Method to called to create value instance from JSON Object using an intermediate "delegate" value to pass to createor method- Throws:
IOException
JsonProcessingException
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createFromString
- Throws:
IOException
JsonProcessingException
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createFromInt
- Throws:
IOException
JsonProcessingException
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createFromLong
- Throws:
IOException
JsonProcessingException
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createFromDouble
- Throws:
IOException
JsonProcessingException
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createFromBoolean
- Throws:
IOException
JsonProcessingException
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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 . -
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 . -
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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