bsh.classpath
Class ClassManagerImpl

java.lang.Object
  |
  +--bsh.BshClassManager
        |
        +--bsh.classpath.ClassManagerImpl

public class ClassManagerImpl
extends BshClassManager

        Manage all classloading in BeanShell.
        Allows classpath extension and class file reloading.

        This class holds the implementation of the BshClassManager so that it
        can be separated from the core package.

        This class currently relies on 1.2 for BshClassLoader and weak references.
        Is there a workaround for weak refs?  If so we could make this work
        with 1.1 by supplying our own classloader code...

        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.

        Note: we may need some synchronization in here

        Note on jdk1.2 dependency:

        We are forced to use weak references here to accomodate all of the 
        fleeting namespace listeners.  (NameSpaces must be informed if the class 
        space changes so that they can un-cache names).  I had the interesting 
        thought that a way around this would be to implement BeanShell's own 
        garbage collector...  Then I came to my senses and said - screw it, 
        class re-loading will require 1.2.
        


Nested Class Summary
 
Nested classes inherited from class bsh.BshClassManager
BshClassManager.Listener
 
Field Summary
 
Fields inherited from class bsh.BshClassManager
absoluteClassCache, absoluteNonClasses, resolvedObjectMethods, resolvedStaticMethods
 
Constructor Summary
ClassManagerImpl()
          Used by BshClassManager singleton constructor
 
Method Summary
 void addClassPath(java.net.URL path)
           
 void addListener(BshClassManager.Listener l)
           
 java.lang.Class classForName(java.lang.String name)
          Load the specified class by name, taking into account added classpath and reloaded classes, etc.
protected  void classLoaderChanged()
          Clear global class cache and notify namespaces to clear their class caches.
 void doSuperImport()
          Support for "import *;" Hide details in here as opposed to NameSpace.
 void dump(java.io.PrintWriter i)
           
 java.lang.ClassLoader getBaseLoader()
           
 java.lang.String getClassNameByUnqName(java.lang.String name)
          Return the name or null if none is found, Throw an ClassPathException containing detail if name is ambigous.
 BshClassPath getClassPath()
          Get the full blown classpath.
 java.net.URL getResource(java.lang.String path)
          Get a resource URL using the BeanShell classpath
 java.io.InputStream getResourceAsStream(java.lang.String path)
          Get a resource stream using the BeanShell classpath
protected  boolean hasSuperImport()
          A "super import" ("import *") operation has been performed.
 java.lang.Class plainClassForName(java.lang.String name)
          Delegate for bottom level implementation of Class.forName().
 void reloadAllClasses()
          Overlay the entire path with a new class loader.
 void reloadClasses(java.lang.String[] classNames)
          Reloading classes means creating a new classloader and using it whenever we are asked for classes in the appropriate space.
 void reloadPackage(java.lang.String pack)
          Reload all classes in the specified package: e.g.
 void removeListener(BshClassManager.Listener l)
           
 void reset()
          Clear all classloading behavior and class caches and reset to initial state.
 void setClassPath(java.net.URL[] cp)
          Set a new base classpath and create a new base classloader.
 
Methods inherited from class bsh.BshClassManager
cacheClassInfo, cacheResolvedMethod, classExists, clearCaches, cmUnavailable, createClassManager, getResolvedMethod, noClassDefFound, setClassLoader
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

ClassManagerImpl

public ClassManagerImpl()
Used by BshClassManager singleton constructor

Method Detail

classForName

public java.lang.Class classForName(java.lang.String name)
Description copied from class: BshClassManager
Load the specified class by name, taking into account added classpath and reloaded classes, etc.

Overrides:
classForName in class BshClassManager
Returns:
the class or null

plainClassForName

public java.lang.Class plainClassForName(java.lang.String name)
                                  throws java.lang.ClassNotFoundException
Delegate for bottom level implementation of Class.forName(). This is here solely to provide for Java version specific features. In this case - the Thread getContextClassLoader() which is required to get bsh to see user classpath when it's installed in a web application or in the jre/lib/ext directory.

Overrides:
plainClassForName in class BshClassManager
Returns:
the class
java.lang.ClassNotFoundException
See Also:
BshClassManager.plainClassForName()

getResource

public java.net.URL getResource(java.lang.String path)
Get a resource URL using the BeanShell classpath

Overrides:
getResource in class BshClassManager
Parameters:
path - should be an absolute path

getResourceAsStream

public java.io.InputStream getResourceAsStream(java.lang.String path)
Get a resource stream using the BeanShell classpath

Overrides:
getResourceAsStream in class BshClassManager
Parameters:
path - should be an absolute path

addClassPath

public void addClassPath(java.net.URL path)
                  throws java.io.IOException
Overrides:
addClassPath in class BshClassManager
java.io.IOException

reset

public void reset()
Clear all classloading behavior and class caches and reset to initial state.

Overrides:
reset in class BshClassManager

setClassPath

public void setClassPath(java.net.URL[] cp)
Set a new base classpath and create a new base classloader. This means all types change.

Overrides:
setClassPath in class BshClassManager

reloadAllClasses

public void reloadAllClasses()
                      throws ClassPathException
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).

Overrides:
reloadAllClasses in class BshClassManager
ClassPathException

reloadClasses

public void reloadClasses(java.lang.String[] classNames)
                   throws ClassPathException
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

Overrides:
reloadClasses in class BshClassManager
ClassPathException

reloadPackage

public void reloadPackage(java.lang.String pack)
                   throws ClassPathException
Reload all classes in the specified package: e.g. "com.sun.tools" The special package name "" can be used to refer to unpackaged classes.

Overrides:
reloadPackage in class BshClassManager
ClassPathException

getClassPath

public BshClassPath getClassPath()
                          throws ClassPathException
Get the full blown classpath.

ClassPathException

doSuperImport

public void doSuperImport()
                   throws UtilEvalError
Support for "import *;" Hide details in here as opposed to NameSpace.

Overrides:
doSuperImport in class BshClassManager
UtilEvalError

hasSuperImport

protected boolean hasSuperImport()
Description copied from class: BshClassManager
A "super import" ("import *") operation has been performed.

Overrides:
hasSuperImport in class BshClassManager

getClassNameByUnqName

public java.lang.String getClassNameByUnqName(java.lang.String name)
                                       throws ClassPathException
Return the name or null if none is found, Throw an ClassPathException containing detail if name is ambigous.

Overrides:
getClassNameByUnqName in class BshClassManager
ClassPathException

addListener

public void addListener(BshClassManager.Listener l)
Overrides:
addListener in class BshClassManager

removeListener

public void removeListener(BshClassManager.Listener l)
Overrides:
removeListener in class BshClassManager

getBaseLoader

public java.lang.ClassLoader getBaseLoader()

classLoaderChanged

protected void classLoaderChanged()
Clear global class cache and notify namespaces to clear their class caches. The listener list is implemented with weak references so that we will not keep every namespace in existence forever.

Overrides:
classLoaderChanged in class BshClassManager

dump

public void dump(java.io.PrintWriter i)
Overrides:
dump in class BshClassManager


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