bsh

Class NameSpace

Implemented Interfaces:
java.io.Serializable, BshClassManager.Listener, NameSource
Known Direct Subclasses:
ExternalNameSpace

public class NameSpace
extends java.lang.Object
implements java.io.Serializable, BshClassManager.Listener, NameSource

A namespace in which methods, variables, and imports (class names) live. This is package public because it is used in the implementation of some bsh commands. However for normal use you should be using methods on bsh.Interpreter to interact with your scripts.

A bsh.This object is a thin layer over a NameSpace that associates it with an Interpreter instance. Together they comprise a Bsh scripted object context.

Note: I'd really like to use collections here, but we have to keep this compatible with JDK1.1

See Also:
Serialized Form

Field Summary

static NameSpace
JAVACODE
protected Hashtable
importedClasses

Constructor Summary

NameSpace(BshClassManager classManager, String name)
NameSpace(NameSpace parent, String name)
NameSpace(NameSpace parent, BshClassManager classManager, String name)

Method Summary

void
addNameSourceListener(NameSource.Listener listener)
Implements NameSource Add a listener who is notified upon changes to names in this space.
void
classLoaderChanged()
Clear all cached classes and names
void
clear()
Clear all variables, methods, and imports from this namespace.
void
doSuperImport()
Perform "import *;" causing the entire classpath to be mapped.
Object
get(String name, Interpreter interpreter)
Resolve name to an object through this namespace.
String[]
getAllNames()
Implements NameSource
protected void
getAllNamesAux(Vector vec)
Helper for implementing NameSource
Class
getClass(String name)
Load a class through this namespace taking into account imports.
BshClassManager
getClassManager()
Object
getCommand(String name, Class[] argTypes, Interpreter interpreter)
A command is a scripted method or compiled command class implementing a specified method signature.
Variable[]
getDeclaredVariables()
This
getGlobal(Interpreter declaringInterpreter)
Get the top level namespace or this namespace if we are the top.
protected BshMethod
getImportedMethod(String name, Class[] sig)
protected Variable
getImportedVar(String name)
int
getInvocationLine()
String
getInvocationText()
BshMethod
getMethod(String name, Class[] sig)
BshMethod
getMethod(String name, Class[] sig, boolean declaredOnly)
Get the bsh method matching the specified signature declared in this name space or a parent.
String[]
getMethodNames()
Get the names of methods declared in this namespace.
BshMethod[]
getMethods()
Get the methods defined in this namespace.
String
getName()
The name of this namespace.
NameSpace
getParent()
Get the parent namespace.
This
getSuper(Interpreter declaringInterpreter)
Get the parent namespace' This reference or this namespace' This reference if we are the top.
Object
getVariable(String name)
Get the specified variable in this namespace or a parent namespace.
Object
getVariable(String name, boolean recurse)
Get the specified variable in this namespace.
protected Variable
getVariableImpl(String name, boolean recurse)
Locate a variable and return the Variable object with optional recursion through parent name spaces.
String[]
getVariableNames()
Get the names of variables defined in this namespace.
static Class
identifierToClass(ClassIdentifier ci)
This is a helper method for working inside of bsh scripts and commands.
void
importClass(String name)
Import a class name.
void
importCommands(String name)
Import scripted or compiled BeanShell commands in the following package in the classpath.
void
importObject(Object obj)
Import a compiled Java object's methods and variables into this namespace.
void
importPackage(String name)
subsequent imports override earlier ones
void
importStatic(Class clas)
Object
invokeMethod(String methodName, Object[] args, Interpreter interpreter)
Invoke a method in this namespace with the specified args and interpreter reference.
Object
invokeMethod(String methodName, Object[] args, Interpreter interpreter, CallStack callstack, bsh.SimpleNode callerInfo)
This method simply delegates to This.invokeMethod();

void
loadDefaultImports()
Import standard packages.
void
nameSpaceChanged()
Clear all cached classes and names
void
prune()
Used for serialization
void
setMethod(String name, BshMethod method)
Note: this is primarily for internal use.
void
setName(String name)
void
setParent(NameSpace parent)
void
setTypedVariable(String name, Class type, Object value, boolean isFinal)
Deprecated. See #setTypedVariable( String, Class, Object, Modifiers )
void
setTypedVariable(String name, Class type, Object value, Modifiers modifiers)
Declare a variable in the local scope and set its initial value.
void
setVariable(String name, Object value, boolean strictJava)
Set the variable through this namespace.
String
toString()
void
unsetVariable(String name)
Remove the variable from the namespace.
protected Object
unwrapVariable(Variable var)
Unwrap a variable to its value.

Field Details

JAVACODE

public static final NameSpace JAVACODE

importedClasses

protected Hashtable importedClasses

Constructor Details

NameSpace

public NameSpace(BshClassManager classManager,
                 String name)

NameSpace

public NameSpace(NameSpace parent,
                 String name)

NameSpace

public NameSpace(NameSpace parent,
                 BshClassManager classManager,
                 String name)

Method Details

addNameSourceListener

public void addNameSourceListener(NameSource.Listener listener)
Implements NameSource Add a listener who is notified upon changes to names in this space.
Specified by:
addNameSourceListener in interface NameSource

classLoaderChanged

public void classLoaderChanged()
Clear all cached classes and names
Specified by:
classLoaderChanged in interface BshClassManager.Listener

clear

public void clear()
Clear all variables, methods, and imports from this namespace. If this namespace is the root, it will be reset to the default imports.

doSuperImport

public void doSuperImport()
            throws UtilEvalError
Perform "import *;" causing the entire classpath to be mapped. This can take a while.

get

public Object get(String name,
                  Interpreter interpreter)
            throws UtilEvalError
Resolve name to an object through this namespace.

getAllNames

public String[] getAllNames()
Implements NameSource
Specified by:
getAllNames in interface NameSource
Returns:
all variable and method names in this and all parent namespaces

getAllNamesAux

protected void getAllNamesAux(Vector vec)
Helper for implementing NameSource

getClass

public Class getClass(String name)
            throws UtilEvalError
Load a class through this namespace taking into account imports. The class search will proceed through the parent namespaces if necessary.
Returns:
null if not found.

getClassManager

public BshClassManager getClassManager()

getCommand

public Object getCommand(String name,
                         Class[] argTypes,
                         Interpreter interpreter)
            throws UtilEvalError
A command is a scripted method or compiled command class implementing a specified method signature. Commands are loaded from the classpath and may be imported using the importCommands() method.

This method searches the imported commands packages for a script or command object corresponding to the name of the method. If it is a script the script is sourced into this namespace and the BshMethod for the requested signature is returned. If it is a compiled class the class is returned. (Compiled command classes implement static invoke() methods).

The imported packages are searched in reverse order, so that later imports take priority. Currently only the first object (script or class) with the appropriate name is checked. If another, overloaded form, is located in another package it will not currently be found. This could be fixed.

Parameters:
name - is the name of the desired command method
argTypes - is the signature of the desired command method.
Returns:
a BshMethod, Class, or null if no such command is found.
Throws:
UtilEvalError - if loadScriptedCommand throws UtilEvalError i.e. on errors loading a script that was found

getDeclaredVariables

public Variable[] getDeclaredVariables()

getGlobal

public This getGlobal(Interpreter declaringInterpreter)
Get the top level namespace or this namespace if we are the top. Note: this method should probably return type bsh.This to be consistent with getThis();

getImportedMethod

protected BshMethod getImportedMethod(String name,
                                      Class[] sig)
            throws UtilEvalError

getImportedVar

protected Variable getImportedVar(String name)
            throws UtilEvalError

getInvocationLine

public int getInvocationLine()

getInvocationText

public String getInvocationText()

getMethod

public BshMethod getMethod(String name,
                           Class[] sig)
            throws UtilEvalError
See Also:
getMethod( String, Class [], boolean ), getMethod( String, Class [] )

getMethod

public BshMethod getMethod(String name,
                           Class[] sig,
                           boolean declaredOnly)
            throws UtilEvalError
Get the bsh method matching the specified signature declared in this name space or a parent.

Note: this method is primarily intended for use internally. If you use this method outside of the bsh package you will have to be familiar with BeanShell's use of the Primitive wrapper class.

Parameters:
declaredOnly - if true then only methods declared directly in this namespace will be found and no inherited or imported methods will be visible.
Returns:
the BshMethod or null if not found
See Also:
Primitive

getMethodNames

public String[] getMethodNames()
Get the names of methods declared in this namespace. (This does not include methods in parent namespaces).

getMethods

public BshMethod[] getMethods()
Get the methods defined in this namespace. (This does not show methods in parent namespaces). Note: This will probably be renamed getDeclaredMethods()

getName

public String getName()
The name of this namespace. If the namespace is a method body namespace then this is the name of the method. If it's a class or class instance then it's the name of the class.

getParent

public NameSpace getParent()
Get the parent namespace. Note: this isn't quite the same as getSuper(). getSuper() returns 'this' if we are at the root namespace.

getSuper

public This getSuper(Interpreter declaringInterpreter)
Get the parent namespace' This reference or this namespace' This reference if we are the top.

getVariable

public Object getVariable(String name)
            throws UtilEvalError
Get the specified variable in this namespace or a parent namespace.

Note: this method is primarily intended for use internally. If you use this method outside of the bsh package you will have to use Primitive.unwrap() to get primitive values.

Returns:
The variable value or Primitive.VOID if it is not defined.

getVariable

public Object getVariable(String name,
                          boolean recurse)
            throws UtilEvalError
Get the specified variable in this namespace.
Parameters:
recurse - If recurse is true then we recursively search through parent namespaces for the variable.

Note: this method is primarily intended for use internally. If you use this method outside of the bsh package you will have to use Primitive.unwrap() to get primitive values.

Returns:
The variable value or Primitive.VOID if it is not defined.

getVariableImpl

protected Variable getVariableImpl(String name,
                                   boolean recurse)
            throws UtilEvalError
Locate a variable and return the Variable object with optional recursion through parent name spaces.

If this namespace is static, return only static variables.

Returns:
the Variable value or null if it is not defined

getVariableNames

public String[] getVariableNames()
Get the names of variables defined in this namespace. (This does not show variables in parent namespaces).

identifierToClass

public static Class identifierToClass(ClassIdentifier ci)
This is a helper method for working inside of bsh scripts and commands. In that context it is impossible to see a ClassIdentifier object for what it is. Attempting to access a method on a ClassIdentifier will look like a static method invocation. This method is in NameSpace for convenience (you don't have to import bsh.ClassIdentifier to use it );

importClass

public void importClass(String name)
Import a class name. Subsequent imports override earlier ones

importCommands

public void importCommands(String name)
Import scripted or compiled BeanShell commands in the following package in the classpath. You may use either "/" path or "." package notation. e.g. importCommands("/bsh/commands") or importCommands("bsh.commands") are equivalent. If a relative path style specifier is used then it is made into an absolute path by prepending "/".

importObject

public void importObject(Object obj)
Import a compiled Java object's methods and variables into this namespace. When no scripted method / command or variable is found locally in this namespace method / fields of the object will be checked. Objects are checked in the order of import with later imports taking precedence.


importPackage

public void importPackage(String name)
subsequent imports override earlier ones

importStatic

public void importStatic(Class clas)

invokeMethod

public Object invokeMethod(String methodName,
                           Object[] args,
                           Interpreter interpreter)
            throws EvalError
Invoke a method in this namespace with the specified args and interpreter reference. No caller information or call stack is required. The method will appear as if called externally from Java.

See Also:
bsh.This.invokeMethod( String methodName, Object [] args, Interpreter interpreter, CallStack callstack, SimpleNode callerInfo, boolean )

invokeMethod

public Object invokeMethod(String methodName,
                           Object[] args,
                           Interpreter interpreter,
                           CallStack callstack,
                           bsh.SimpleNode callerInfo)
            throws EvalError
This method simply delegates to This.invokeMethod();

See Also:
bsh.This.invokeMethod( String methodName, Object [] args, Interpreter interpreter, CallStack callstack, SimpleNode callerInfo )

loadDefaultImports

public void loadDefaultImports()
Import standard packages. Currently:
importClass("bsh.EvalError");
importClass("bsh.Interpreter");
importPackage("javax.swing.event");
importPackage("javax.swing");
importPackage("java.awt.event");
importPackage("java.awt");
importPackage("java.net");
importPackage("java.util");
importPackage("java.io");
importPackage("java.lang");
importCommands("/bsh/commands");

nameSpaceChanged

public void nameSpaceChanged()
Clear all cached classes and names

prune

public void prune()
Used for serialization

setMethod

public void setMethod(String name,
                      BshMethod method)
            throws UtilEvalError
Note: this is primarily for internal use.

setName

public void setName(String name)

setParent

public void setParent(NameSpace parent)

setTypedVariable

public void setTypedVariable(String name,
                             Class type,
                             Object value,
                             boolean isFinal)
            throws UtilEvalError

Deprecated. See #setTypedVariable( String, Class, Object, Modifiers )


setTypedVariable

public void setTypedVariable(String name,
                             Class type,
                             Object value,
                             Modifiers modifiers)
            throws UtilEvalError
Declare a variable in the local scope and set its initial value. Value may be null to indicate that we would like the default value for the variable type. (e.g. 0 for integer types, null for object types). An existing typed variable may only be set to the same type. If an untyped variable of the same name exists it will be overridden with the new typed var. The set will perform a Types.getAssignableForm() on the value if necessary.

Note: this method is primarily intended for use internally. If you use this method outside of the bsh package and wish to set variables with primitive values you will have to wrap them using bsh.Primitive.

Parameters:
value - If value is null, you'll get the default value for the type
modifiers - may be null
See Also:
Primitive

setVariable

public void setVariable(String name,
                        Object value,
                        boolean strictJava)
            throws UtilEvalError
Set the variable through this namespace. This method obeys the LOCALSCOPING property to determine how variables are set.

Note: this method is primarily intended for use internally. If you use this method outside of the bsh package and wish to set variables with primitive values you will have to wrap them using bsh.Primitive.

Parameters:
strictJava - specifies whether strict java rules are applied.

toString

public String toString()

unsetVariable

public void unsetVariable(String name)
Remove the variable from the namespace.

unwrapVariable

protected Object unwrapVariable(Variable var)
            throws UtilEvalError
Unwrap a variable to its value.
Returns:
return the variable value. A null var is mapped to Primitive.VOID

B) 2000-2005 pat@pat.net :-)