BshClassManager manages all classloading in BeanShell.
It also supports a dynamically loaded extension (bsh.classpath package)
which allows classpath extension and class file reloading.
Currently the extension relies on 1.2 for BshClassLoader and weak
references.
See http://www.beanshell.org/manual/classloading.html for details
on the bsh classloader architecture.
Bsh has a multi-tiered class loading architecture. No class loader is
used unless/until the classpath is modified or a class is reloaded.
absoluteClassCache
protected Hashtable absoluteClassCache
Global cache for things we know are classes.
Note: these should probably be re-implemented with Soft references.
(as opposed to strong or Weak)
absoluteNonClasses
protected Hashtable absoluteNonClasses
Global cache for things we know are *not* classes.
Note: these should probably be re-implemented with Soft references.
(as opposed to strong or Weak)
definingClasses
protected Hashtable definingClasses
definingClassesBaseNames
protected Hashtable definingClassesBaseNames
externalClassLoader
protected ClassLoader externalClassLoader
An external classloader supplied by the setClassLoader() command.
resolvedObjectMethods
protected Hashtable resolvedObjectMethods
Caches for resolved object and static methods.
We keep these maps separate to support fast lookup in the general case
where the method may be either.
resolvedStaticMethods
protected Hashtable resolvedStaticMethods
addClassPath
public void addClassPath(URL path)
throws IOException
cacheClassInfo
public void cacheClassInfo(String name,
Class value)
Cache info about whether name is a class or not.
value
- if value is non-null, cache the class
if value is null, set the flag that it is *not* a class to
speed later resolution
cacheResolvedMethod
public void cacheResolvedMethod(Class clas,
Class[] types,
Method method)
Cache a resolved (possibly overloaded) method based on the
argument types used to invoke it, subject to classloader change.
Static and Object methods are cached separately to support fast lookup
in the general case where either will do.
classExists
public boolean classExists(String name)
classForName
public Class classForName(String name)
Load the specified class by name, taking into account added classpath
and reloaded classes, etc.
Note: Again, this is just a trivial implementation.
See bsh.classpath.ClassManagerImpl for the fully functional class
management package.
- the class or null
classLoaderChanged
protected void classLoaderChanged()
clearCaches
protected void clearCaches()
Clear the caches in BshClassManager
void #reset() for external usage
createClassManager
public static BshClassManager createClassManager(Interpreter interpreter)
Create a new instance of the class manager.
Class manager instnaces are now associated with the interpreter.
bsh.Interpreter.getClassManager()
, bsh.Interpreter.setClassLoader( ClassLoader )
defineClass
public Class defineClass(String name,
byte[] code)
definingClass
protected void definingClass(String className)
Flag the class name as being in the process of being defined.
The class manager will not attempt to load it.
doSuperImport
protected void doSuperImport()
throws UtilEvalError
Support for "import *;"
Hide details in here as opposed to NameSpace.
doneDefiningClass
protected void doneDefiningClass(String className)
Indicate that the specified class name has been defined and may be
loaded normally.
dump
public void dump(PrintWriter pw)
getClassBeingDefined
protected String getClassBeingDefined(String className)
This method is a temporary workaround used with definingClass.
It is to be removed at some point.
getClassNameByUnqName
protected String getClassNameByUnqName(String name)
throws UtilEvalError
Return the name or null if none is found,
Throw an ClassPathException containing detail if name is ambigous.
getResolvedMethod
protected Method getResolvedMethod(Class clas,
String methodName,
Class[] types,
boolean onlyStatic)
Return a previously cached resolved method.
onlyStatic
- specifies that only a static method may be returned.
- the Method or null
getResource
public URL getResource(String path)
Get a resource URL using the BeanShell classpath
path
- should be an absolute path
getResourceAsStream
public InputStream getResourceAsStream(String path)
Get a resource stream using the BeanShell classpath
path
- should be an absolute path
hasSuperImport
protected boolean hasSuperImport()
A "super import" ("import *") operation has been performed.
isClassBeingDefined
protected boolean isClassBeingDefined(String className)
loadSourceClass
protected Class loadSourceClass(String name)
noClassDefFound
protected static Error noClassDefFound(String className,
Error e)
Annotate the NoClassDefFoundError with some info about the class
we were trying to load.
plainClassForName
public Class plainClassForName(String name)
throws ClassNotFoundException
Perform a plain Class.forName() or call the externally provided
classloader.
If a BshClassManager implementation is loaded the call will be
delegated to it, to allow for additional hooks.
This simply wraps that bottom level class lookup call and provides a
central point for monitoring and handling certain Java version
dependent bugs, etc.
- the class
classForName(String)
reloadAllClasses
public void reloadAllClasses()
throws UtilEvalError
Overlay the entire path with a new class loader.
Set the base path to the user path + base path.
No point in including the boot class path (can't reload thos).
reloadClasses
public void reloadClasses(String[] classNames)
throws UtilEvalError
Reloading classes means creating a new classloader and using it
whenever we are asked for classes in the appropriate space.
For this we use a DiscreteFilesClassLoader
reloadPackage
public void reloadPackage(String pack)
throws UtilEvalError
Reload all classes in the specified package: e.g. "com.sun.tools"
The special package name "" can be used to refer
to unpackaged classes.
reset
public void reset()
Clear all loaders and start over. No class loading.
setClassLoader
public void setClassLoader(ClassLoader externalCL)
Set an external class loader. BeanShell will use this at the same
point it would otherwise use the plain Class.forName().
i.e. if no explicit classpath management is done from the script
(addClassPath(), setClassPath(), reloadClasses()) then BeanShell will
only use the supplied classloader. If additional classpath management
is done then BeanShell will perform that in addition to the supplied
external classloader.
However BeanShell is not currently able to reload
classes supplied through the external classloader.
setClassPath
public void setClassPath(URL[] cp)
throws UtilEvalError
Set a new base classpath and create a new base classloader.
This means all types change.