org.codehaus.groovy.control
Class ClassNodeResolver

java.lang.Object
  org.codehaus.groovy.control.ClassNodeResolver

public class ClassNodeResolver
extends Object

This class is used as a plugable way to resolve class names. An instance of this class has to be added to CompilationUnit using CompilationUnit.setClassNodeResolver(ClassNodeResolver). The CompilationUnit will then set the resolver on the ResolveVisitor each time new. The ResolveVisitor will prepare name lookup and then finally ask the resolver if the class exists. This resolver then can return either a SourceUnit or a ClassNode. In case of a SourceUnit the compiler is notified that a new source is to be added to the compilation queue. In case of a ClassNode no further action than the resolving is done. The lookup result is stored in the helper class ClassNodeResolver.LookupResult. This class provides a class cache to cache lookups. If you don't want this, you have to override the methods cacheClass(String, ClassNode) and getFromClassCache(String). Custom lookup logic is supposed to go into the method findClassNode(String, CompilationUnit) while the entry method is resolveName(String, CompilationUnit)

Author:

Jochen "blackdrag" Theodorou

Nested Class Summary

static class

ClassNodeResolver.LookupResult Helper class to return either a SourceUnit or ClassNode.

Field Summary

protected static ClassNode

NO_CLASS Internal helper used to indicate a cache hit for a class that does not exist.

Constructor Summary

ClassNodeResolver()

Method Summary

void	cacheClass(String name, ClassNode res) caches a ClassNode
ClassNodeResolver.LookupResult	findClassNode(String name, CompilationUnit compilationUnit) Extension point for custom lookup logic of finding ClassNodes.
ClassNode	getFromClassCache(String name) returns whatever is stored in the class cache for the given name
ClassNodeResolver.LookupResult	resolveName(String name, CompilationUnit compilationUnit) Resolves the name of a class to a SourceUnit or ClassNode.

Methods inherited from class java.lang.Object

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

Field Detail

NO_CLASS

protected static final ClassNode NO_CLASS

Internal helper used to indicate a cache hit for a class that does not exist. This way further lookups through a slow findClassNode(String, CompilationUnit) path can be avoided. WARNING: This class is not to be used outside of ClassNodeResolver.

Constructor Detail

ClassNodeResolver

public ClassNodeResolver()

Method Detail

resolveName

public ClassNodeResolver.LookupResult resolveName(String name,
                                                  CompilationUnit compilationUnit)

Resolves the name of a class to a SourceUnit or ClassNode. If no class or source is found this method returns null. A lookup is done by first asking the cache if there is an entry for the class already available to then call findClassNode(String, CompilationUnit). The result of that method call will be cached if a ClassNode is found. If a SourceUnit is found, this method will not be asked later on again for that class, because ResolveVisitor will first ask the CompilationUnit for classes in the compilation queue and it will find the class for that SourceUnit there then. method return a ClassNode instead of a SourceUnit, the res

Parameters:

name - - the name of the class

compilationUnit - - the current CompilationUnit

Returns:

the LookupResult

cacheClass

public void cacheClass(String name,
                       ClassNode res)

caches a ClassNode

Parameters:

name - - the name of the class

res - - the ClassNode for that name

getFromClassCache

public ClassNode getFromClassCache(String name)

returns whatever is stored in the class cache for the given name

Parameters:

name - - the name of the class

Returns:

the result of the lookup, which may be null

findClassNode

public ClassNodeResolver.LookupResult findClassNode(String name,
                                                    CompilationUnit compilationUnit)

Extension point for custom lookup logic of finding ClassNodes. Per default this will use the CompilationUnit class loader to do a lookup on the class path and load the needed class using that loader. Or if a script is found and that script is seen as "newer", the script will be used instead of the class.

Parameters:

name - - the name of the class

compilationUnit - - the current compilation unit

Returns:

the lookup result