org.springframework.core

Class LocalVariableTableParameterNameDiscoverer

java.lang.Object

org.springframework.core.LocalVariableTableParameterNameDiscoverer

All Implemented Interfaces:

ParameterNameDiscoverer

public class LocalVariableTableParameterNameDiscoverer
extends java.lang.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.

Since:

2.0

Author:

Adrian Colyer, Costin Leau, Juergen Hoeller, Chris Beams

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	LocalVariableTableParameterNameDiscoverer.LocalVariableTableVisitor
private static class	LocalVariableTableParameterNameDiscoverer.ParameterNameDiscoveringVisitor Helper class that inspects all methods (constructor included) and then attempts to find the parameter names for that member.

Field Summary

Fields

Modifier and Type	Field and Description
private static Log	logger
private static java.util.Map<java.lang.reflect.Member,java.lang.String[]>	NO_DEBUG_INFO_MAP
private java.util.Map<java.lang.Class<?>,java.util.Map<java.lang.reflect.Member,java.lang.String[]>>	parameterNamesCache

Constructor Summary

Constructors

Constructor and Description
LocalVariableTableParameterNameDiscoverer()

Method Summary

Modifier and Type	Method and Description
java.lang.String[]	getParameterNames(java.lang.reflect.Constructor<?> ctor) Return parameter names for this constructor, or null if they cannot be determined.
java.lang.String[]	getParameterNames(java.lang.reflect.Method method) Return parameter names for this method, or null if they cannot be determined.
private java.util.Map<java.lang.reflect.Member,java.lang.String[]>	inspectClass(java.lang.Class<?> clazz) Inspects the target class.

Methods inherited from class java.lang.Object

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

Field Detail

logger

private static final Log logger

NO_DEBUG_INFO_MAP

private static final java.util.Map<java.lang.reflect.Member,java.lang.String[]> NO_DEBUG_INFO_MAP

parameterNamesCache

private final java.util.Map<java.lang.Class<?>,java.util.Map<java.lang.reflect.Member,java.lang.String[]>> parameterNamesCache

Constructor Detail

LocalVariableTableParameterNameDiscoverer

public LocalVariableTableParameterNameDiscoverer()

Method Detail

getParameterNames

public java.lang.String[] getParameterNames(java.lang.reflect.Method method)

Description copied from interface: ParameterNameDiscoverer

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

Specified by:

getParameterNames in interface ParameterNameDiscoverer

Parameters:

method - method to find parameter names for

Returns:

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

getParameterNames

public java.lang.String[] getParameterNames(java.lang.reflect.Constructor<?> ctor)

Description copied from interface: ParameterNameDiscoverer

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

Specified by:

getParameterNames in interface ParameterNameDiscoverer

Parameters:

ctor - constructor to find parameter names for

Returns:

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

inspectClass

private java.util.Map<java.lang.reflect.Member,java.lang.String[]> inspectClass(java.lang.Class<?> clazz)

Inspects the target class. Exceptions will be logged and a maker map returned to indicate the lack of debug information.