org.springframework.core
Class MethodParameter

java.lang.Object
  extended by org.springframework.core.MethodParameter

public class MethodParameter
extends Object

Helper class that encapsulates the specification of a method parameter, i.e. a Method or Constructor plus a parameter index and a nested type index for a declared generic type. Useful as a specification object to pass along.

Used by GenericCollectionTypeResolver, BeanWrapperImpl and AbstractBeanFactory.

Since:
2.0
Author:
Juergen Hoeller, Rob Harrop, Andy Clement
See Also:
GenericCollectionTypeResolver

Constructor Summary
MethodParameter(Constructor constructor, int parameterIndex)
          Create a new MethodParameter for the given constructor, with nesting level 1.
MethodParameter(Constructor constructor, int parameterIndex, int nestingLevel)
          Create a new MethodParameter for the given constructor.
MethodParameter(Method method, int parameterIndex)
          Create a new MethodParameter for the given method, with nesting level 1.
MethodParameter(Method method, int parameterIndex, int nestingLevel)
          Create a new MethodParameter for the given method.
MethodParameter(MethodParameter original)
          Copy constructor, resulting in an independent MethodParameter object based on the same metadata and cache state that the original object was in.
 
Method Summary
 void decreaseNestingLevel()
          Decrease this parameter's nesting level.
static MethodParameter forMethodOrConstructor(Object methodOrConstructor, int parameterIndex)
          Create a new MethodParameter for the given method or constructor.
 Annotation[] getAnnotations()
          Return the annotations associated with the target method/constructor itself.
 Constructor getConstructor()
          Return the wrapped Constructor, if any.
 Class getDeclaringClass()
          Return the class that declares the underlying Method or Constructor.
 Type getGenericParameterType()
          Return the generic type of the method/constructor parameter.
 Method getMethod()
          Return the wrapped Method, if any.
 int getNestingLevel()
          Return the nesting level of the target type (typically 1; e.g.
 Annotation[] getParameterAnnotations()
          Return the annotations associated with the specific method/constructor parameter.
 int getParameterIndex()
          Return the index of the method/constructor parameter.
 String getParameterName()
          Return the name of the method/constructor parameter.
 Class<?> getParameterType()
          Return the type of the method/constructor parameter.
 Integer getTypeIndexForCurrentLevel()
          Return the type index for the current nesting level.
 Integer getTypeIndexForLevel(int nestingLevel)
          Return the type index for the specified nesting level.
 void increaseNestingLevel()
          Increase this parameter's nesting level.
 void initParameterNameDiscovery(ParameterNameDiscoverer parameterNameDiscoverer)
          Initialize parameter name discovery for this method parameter.
 void setTypeIndexForCurrentLevel(int typeIndex)
          Set the type index for the current nesting level.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

MethodParameter

public MethodParameter(Method method,
                       int parameterIndex)
Create a new MethodParameter for the given method, with nesting level 1.

Parameters:
method - the Method to specify a parameter for
parameterIndex - the index of the parameter

MethodParameter

public MethodParameter(Method method,
                       int parameterIndex,
                       int nestingLevel)
Create a new MethodParameter for the given method.

Parameters:
method - the Method to specify a parameter for
parameterIndex - the index of the parameter (-1 for the method return type; 0 for the first method parameter, 1 for the second method parameter, etc)
nestingLevel - the nesting level of the target type (typically 1; e.g. in case of a List of Lists, 1 would indicate the nested List, whereas 2 would indicate the element of the nested List)

MethodParameter

public MethodParameter(Constructor constructor,
                       int parameterIndex)
Create a new MethodParameter for the given constructor, with nesting level 1.

Parameters:
constructor - the Constructor to specify a parameter for
parameterIndex - the index of the parameter

MethodParameter

public MethodParameter(Constructor constructor,
                       int parameterIndex,
                       int nestingLevel)
Create a new MethodParameter for the given constructor.

Parameters:
constructor - the Constructor to specify a parameter for
parameterIndex - the index of the parameter
nestingLevel - the nesting level of the target type (typically 1; e.g. in case of a List of Lists, 1 would indicate the nested List, whereas 2 would indicate the element of the nested List)

MethodParameter

public MethodParameter(MethodParameter original)
Copy constructor, resulting in an independent MethodParameter object based on the same metadata and cache state that the original object was in.

Parameters:
original - the original MethodParameter object to copy from
Method Detail

getMethod

public Method getMethod()
Return the wrapped Method, if any.

Note: Either Method or Constructor is available.

Returns:
the Method, or null if none

getConstructor

public Constructor getConstructor()
Return the wrapped Constructor, if any.

Note: Either Method or Constructor is available.

Returns:
the Constructor, or null if none

getDeclaringClass

public Class getDeclaringClass()
Return the class that declares the underlying Method or Constructor.


getParameterIndex

public int getParameterIndex()
Return the index of the method/constructor parameter.

Returns:
the parameter index (never negative)

getParameterType

public Class<?> getParameterType()
Return the type of the method/constructor parameter.

Returns:
the parameter type (never null)

getGenericParameterType

public Type getGenericParameterType()
Return the generic type of the method/constructor parameter.

Returns:
the parameter type (never null)

getAnnotations

public Annotation[] getAnnotations()
Return the annotations associated with the target method/constructor itself.


getParameterAnnotations

public Annotation[] getParameterAnnotations()
Return the annotations associated with the specific method/constructor parameter.


initParameterNameDiscovery

public void initParameterNameDiscovery(ParameterNameDiscoverer parameterNameDiscoverer)
Initialize parameter name discovery for this method parameter.

This method does not actually try to retrieve the parameter name at this point; it just allows discovery to happen when the application calls getParameterName() (if ever).


getParameterName

public String getParameterName()
Return the name of the method/constructor parameter.

Returns:
the parameter name (may be null if no parameter name metadata is contained in the class file or no ParameterNameDiscoverer has been set to begin with)

increaseNestingLevel

public void increaseNestingLevel()
Increase this parameter's nesting level.

See Also:
getNestingLevel()

decreaseNestingLevel

public void decreaseNestingLevel()
Decrease this parameter's nesting level.

See Also:
getNestingLevel()

getNestingLevel

public int getNestingLevel()
Return the nesting level of the target type (typically 1; e.g. in case of a List of Lists, 1 would indicate the nested List, whereas 2 would indicate the element of the nested List).


setTypeIndexForCurrentLevel

public void setTypeIndexForCurrentLevel(int typeIndex)
Set the type index for the current nesting level.

Parameters:
typeIndex - the corresponding type index (or null for the default type index)
See Also:
getNestingLevel()

getTypeIndexForCurrentLevel

public Integer getTypeIndexForCurrentLevel()
Return the type index for the current nesting level.

Returns:
the corresponding type index, or null if none specified (indicating the default type index)
See Also:
getNestingLevel()

getTypeIndexForLevel

public Integer getTypeIndexForLevel(int nestingLevel)
Return the type index for the specified nesting level.

Parameters:
nestingLevel - the nesting level to check
Returns:
the corresponding type index, or null if none specified (indicating the default type index)

forMethodOrConstructor

public static MethodParameter forMethodOrConstructor(Object methodOrConstructor,
                                                     int parameterIndex)
Create a new MethodParameter for the given method or constructor.

This is a convenience constructor for scenarios where a Method or Constructor reference is treated in a generic fashion.

Parameters:
methodOrConstructor - the Method or Constructor to specify a parameter for
parameterIndex - the index of the parameter
Returns:
the corresponding MethodParameter instance