org.springframework.core

Class LocalVariableTableParameterNameDiscoverer

java.lang.Object

org.springframework.core.LocalVariableTableParameterNameDiscoverer

All Implemented Interfaces:

ParameterNameDiscoverer

public class LocalVariableTableParameterNameDiscoverer
extends Object
implements ParameterNameDiscoverer

Implementation of ParameterNameDiscoverer that uses the LocalVariableTable information in the method attributes to discover parameter names. Returns null if the class file was compiled without debug information.

Uses ObjectWeb's ASM library for analyzing class files. Each discoverer instance caches the ASM discovered information for each introspected Class, in a thread-safe manner. It is recommended to reuse ParameterNameDiscoverer instances as far as possible.

This discoverer variant is effectively superseded by the Java 8 based StandardReflectionParameterNameDiscoverer but included as a fallback still (for code not compiled with the standard "-parameters" compiler flag).

Since:

2.0

Author:

Adrian Colyer, Costin Leau, Juergen Hoeller, Chris Beams, Sam Brannen

See Also:

StandardReflectionParameterNameDiscoverer, DefaultParameterNameDiscoverer

Constructor Summary

Constructors

Constructor and Description
LocalVariableTableParameterNameDiscoverer()

Method Summary

Modifier and Type	Method and Description
String[]	getParameterNames(Constructor<?> ctor) Return parameter names for a constructor, or null if they cannot be determined.
String[]	getParameterNames(Method method) Return parameter names for a method, or null if they cannot be determined.

Methods inherited from class java.lang.Object

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

Constructor Detail

LocalVariableTableParameterNameDiscoverer

public LocalVariableTableParameterNameDiscoverer()

Method Detail

getParameterNames

@Nullable
public String[] getParameterNames(Method method)

Description copied from interface: ParameterNameDiscoverer

Return parameter names for a method, or null if they cannot be determined.

Individual entries in the array may be null if parameter names are only available for some parameters of the given method but not for others. However, it is recommended to use stub parameter names instead wherever feasible.

Specified by:

getParameterNames in interface ParameterNameDiscoverer

Parameters:

method - the method to find parameter names for

Returns:

an array of parameter names if the names can be resolved, or null if they cannot

getParameterNames

@Nullable
public String[] getParameterNames(Constructor<?> ctor)

Description copied from interface: ParameterNameDiscoverer

Return parameter names for a constructor, or null if they cannot be determined.

Individual entries in the array may be null if parameter names are only available for some parameters of the given constructor but not for others. However, it is recommended to use stub parameter names instead wherever feasible.

Specified by:

getParameterNames in interface ParameterNameDiscoverer

Parameters:

ctor - the constructor to find parameter names for

Returns:

an array of parameter names if the names can be resolved, or null if they cannot