bsh

Class NameSpace

public class NameSpace extends Object implements 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

Field Summary
static NameSpaceJAVACODE
StringnsName
The name of this namespace.
Constructor Summary
NameSpace(NameSpace parent, String name)
NameSpace(BshClassManager classManager, String name)
NameSpace(NameSpace parent, BshClassManager classManager, String name)
Method Summary
voidaddNameSourceListener(NameSource.Listener listener)
Implements NameSource Add a listener who is notified upon changes to names in this space.
protected voidcheckMethodModifiers(BshMethod method)
protected voidcheckVariableModifiers(String name, Modifiers modifiers)
Dissallow static vars outside of a class
voidclassLoaderChanged()
Clear all cached classes and names
voidclear()
Clear all variables, methods, and imports from this namespace.
voiddoSuperImport()
Perform "import *;" causing the entire classpath to be mapped.
Objectget(String name, Interpreter interpreter)
Resolve name to an object through this namespace.
String[]getAllNames()
Implements NameSource
protected voidgetAllNamesAux(Vector vec)
Helper for implementing NameSource
static ObjectgetAssignableForm(Object rhs, Class lhsType)
Determine if the RHS object can be assigned to the LHS type:

1) As in a legal Java assignment (as determined by Reflect.isJavaAssignable()) through widening or promotion

2) Via special BeanShell extensions like interface generation or (gag) numeric-style promotion of primitive wrappers (e.g.

ClassgetClass(String name)
Load a class through this namespace taking into account imports.
BshClassManagergetClassManager()
ObjectgetCommand(String name, Class[] argTypes, Interpreter interpreter)
A command is a scripted method or compiled command class implementing a specified method signature.
NameSpacegetGlobal()
Get the top level namespace or this namespace if we are the top.
intgetInvocationLine()
StringgetInvocationText()
BshMethodgetMethod(String name, Class[] sig)
Get the bsh method matching the specified signature declared in this name space or a parent.
String[]getMethodNames()
Get the names of methods defined in this namespace.
BshMethod[]getMethods()
Get the methods defined in this namespace.
StringgetName()
NameSpacegetParent()
Get the parent namespace.
NameSpacegetSuper()
Get the parent namespace or this namespace if we are the top.
ObjectgetVariable(String name)
Get the specified variable in this namespace or a parent namespace.
ObjectgetVariable(String name, boolean recurse)
Get the specified variable in this namespace.
protected NameSpace.VariablegetVariableImpl(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 ClassidentifierToClass(ClassIdentifier ci)
This is a helper method for working inside of bsh scripts and commands.
voidimportClass(String name)
Import a class name.
voidimportCommands(String name)
Import scripted or compiled BeanShell commands in the following package in the classpath.
voidimportPackage(String name)
subsequent imports override earlier ones
ObjectinvokeMethod(String methodName, Object[] args, Interpreter interpreter)
Invoke a method in this namespace with the specified args and interpreter reference.
ObjectinvokeMethod(String methodName, Object[] args, Interpreter interpreter, CallStack callstack, SimpleNode callerInfo)
This method simply delegates to This.invokeMethod();

protected booleanisVisible(NameSpace.Variable var)
This is a hook to allow ClassNameSpace to add functionality here.
protected booleanisVisible(BshMethod method)
This is a hook to allow ClassNameSpace to add functionality to getMethod()
voidloadDefaultImports()
Import standard packages.
voidnameSpaceChanged()
Clear all cached classes and names
voidprune()
Used for serialization
voidsetMethod(String name, BshMethod method)
Note: this is primarily for internal use.
voidsetName(String name)
voidsetParent(NameSpace parent)
voidsetTypedVariable(String name, Class type, Object value, boolean isFinal)
voidsetTypedVariable(String name, Class type, Object value, Modifiers modifiers)
Declare a variable in the local scope and set its initial value.
voidsetVariable(String name, Object value, boolean strictJava)
Set the variable through this namespace.
StringtoString()
voidunsetVariable(String name)
Remove the variable from the namespace.
protected ObjectunwrapVariable(NameSpace.Variable var)
Unwrap a variable to its value.

Field Detail

JAVACODE

public static final NameSpace JAVACODE

nsName

public String nsName
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.

Constructor Detail

NameSpace

public NameSpace(NameSpace parent, String name)

UNKNOWN: the parent namespace of this namespace. Child namespaces inherit all variables and methods of their parent and can (of course) override / shadow them.

NameSpace

public NameSpace(BshClassManager classManager, String name)

NameSpace

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

Method Detail

addNameSourceListener

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

checkMethodModifiers

protected void checkMethodModifiers(BshMethod method)

checkVariableModifiers

protected void checkVariableModifiers(String name, Modifiers modifiers)
Dissallow static vars outside of a class

Parameters: name is here just to allow the error message to use it

classLoaderChanged

public void classLoaderChanged()
Clear all cached classes and names

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.

See Also: loadDefaultImports

doSuperImport

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

get

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

getAllNames

public String[] getAllNames()
Implements NameSource

Returns: all variable and method names in this and all parent namespaces

getAllNamesAux

protected void getAllNamesAux(Vector vec)
Helper for implementing NameSource

getAssignableForm

public static Object getAssignableForm(Object rhs, Class lhsType)
Determine if the RHS object can be assigned to the LHS type:

1) As in a legal Java assignment (as determined by Reflect.isJavaAssignable()) through widening or promotion

2) Via special BeanShell extensions like interface generation or (gag) numeric-style promotion of primitive wrappers (e.g. Short to Integer).

If the assignment is legal in BeanShell return the assignable form of the RHS.

This method is used in many places throughout bsh including assignment operations and method selection.

In normal cases this functions as a simple check for assignability and the value is returned unchanged. e.g. a String is assignable to an Object, but no conversion is necessary. Similarly an int is assignable to a long, so no conversion is done. In this sense assignability is in terms of what the Java reflection API will allow since the reflection api will do widening conversions in the case of sets on fields and arrays. (CLARIFY: what about method args?)

The primary purpose of the "returning the assignable form" abstraction is to allow non-standard Java assignment conversions. e.g. wrapper conversion for boxing and unboxing. Some of this will be considered standard in Java 1.5.

Parameters: lhsType lhsType is a real Java class type or Java primitive TYPE rhs is a value, bsh.Primitive wrapper, or Primitive.NULL. If it is a Primitive wrapper it will be unwrapped and compared using Reflect.isJavaAssignableFrom(). If it is Primtive.VOID an error will occur.

Returns: an assignable form of the rhs, usually the original rhs if assignable. If the rhs was a Primitive and it was assignable the Primitive will be returned. If the Primitive needed to be auto-boxed to a wrapper type, the wrapper type will be returned.

Throws: UtilEvalError if the assignment cannot be made legally UtilEvalError on rhs of Primitive.VOID (void assignment)

See Also: BSHCastExpression

getClass

public Class getClass(String name)
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)
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

getGlobal

public NameSpace getGlobal()
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();

getInvocationLine

public int getInvocationLine()

getInvocationText

public String getInvocationText()

getMethod

public BshMethod getMethod(String name, Class[] sig)
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.

Returns: the BshMethod or null if not found

See Also: Primitive

getMethodNames

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

getMethods

public BshMethod[] getMethods()
Get the methods defined in this namespace. (This does not show methods in parent namespaces).

getName

public String getName()

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 NameSpace getSuper()
Get the parent namespace or this namespace if we are the top. Note: this method should probably return type bsh.This to be consistent with getThis();

getVariable

public Object getVariable(String name)
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.

See Also: Primitive

getVariable

public Object getVariable(String name, boolean recurse)
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.

See Also: Primitive

getVariableImpl

protected NameSpace.Variable getVariableImpl(String name, boolean recurse)
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 "/".

importPackage

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

invokeMethod

public Object invokeMethod(String methodName, Object[] args, Interpreter interpreter)
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 )

invokeMethod

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

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

isVisible

protected boolean isVisible(NameSpace.Variable var)
This is a hook to allow ClassNameSpace to add functionality here.

isVisible

protected boolean isVisible(BshMethod method)
This is a hook to allow ClassNameSpace to add functionality to getMethod()

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)
Note: this is primarily for internal use.

See Also: Interpreter Interpreter

setName

public void setName(String name)

setParent

public void setParent(NameSpace parent)

setTypedVariable

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

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

setTypedVariable

public void setTypedVariable(String name, Class type, Object value, Modifiers modifiers)
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 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)
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.

See Also:

Setting a new variable (which didn't exist before) or removing a variable causes a namespace change.

toString

public String toString()

unsetVariable

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

unwrapVariable

protected Object unwrapVariable(NameSpace.Variable var)
Unwrap a variable to its value.

Returns: return the variable value. A null var is mapped to Primitive.VOID

B) 2000 pat@pat.net :-)