/*****************************************************************************
* *
* This file is part of the BeanShell Java Scripting distribution. *
* Documentation and updates may be found at http://www.beanshell.org/ *
* *
* Sun Public License Notice: *
* *
* The contents of this file are subject to the Sun Public License Version *
* 1.0 (the "License"); you may not use this file except in compliance with *
* the License. A copy of the License is available at http://www.sun.com *
* *
* The Original Code is BeanShell. The Initial Developer of the Original *
* Code is Pat Niemeyer. Portions created by Pat Niemeyer are Copyright *
* (C) 2000. All Rights Reserved. *
* *
* GNU Public License Notice: *
* *
* Alternatively, the contents of this file may be used under the terms of *
* the GNU Lesser General Public License (the "LGPL"), in which case the *
* provisions of LGPL are applicable instead of those above. If you wish to *
* allow use of your version of this file only under the terms of the LGPL *
* and not to allow others to use your version of this file under the SPL, *
* indicate your decision by deleting the provisions above and replace *
* them with the notice and other provisions required by the LGPL. If you *
* do not delete the provisions above, a recipient may use your version of *
* this file under either the SPL or the LGPL. *
* *
* Patrick Niemeyer (pat@pat.net) *
* Author of Learning Java, O'Reilly & Associates *
* http://www.pat.net/~pat/ *
* *
*****************************************************************************/
package bsh;
import java.lang.reflect.
Array;
import java.lang.reflect.
InvocationTargetException;
/**
New object, new array, or inner class style allocation with body.
*/
class
BSHAllocationExpression extends
SimpleNode
{
BSHAllocationExpression(int
id) { super(
id); }
private static int
innerClassCount = 0;
public
Object eval(
CallStack callstack,
Interpreter interpreter)
throws
EvalError
{
// type is either a class name or a primitive type
SimpleNode type = (
SimpleNode)
jjtGetChild(0);
// args is either constructor arguments or array dimensions
SimpleNode args = (
SimpleNode)
jjtGetChild(1);
if (
type instanceof
BSHAmbiguousName )
{
BSHAmbiguousName name = (
BSHAmbiguousName)
type;
if (
args instanceof
BSHArguments)
return
objectAllocation(
name, (
BSHArguments)
args,
callstack,
interpreter );
else
return
objectArrayAllocation(
name, (
BSHArrayDimensions)
args,
callstack,
interpreter );
}
else
return
primitiveArrayAllocation((
BSHPrimitiveType)
type,
(
BSHArrayDimensions)
args,
callstack,
interpreter );
}
private
Object objectAllocation(
BSHAmbiguousName nameNode,
BSHArguments argumentsNode,
CallStack callstack,
Interpreter interpreter
)
throws
EvalError
{
NameSpace namespace =
callstack.
top();
Object[]
args =
argumentsNode.
getArguments(
callstack,
interpreter );
if (
args == null)
throw new
EvalError( "Null args in new.", this,
callstack );
// Look for scripted class object
Object obj =
nameNode.
toObject(
callstack,
interpreter, false/* force class*/ );
// Try regular class
obj =
nameNode.
toObject(
callstack,
interpreter, true/*force class*/ );
Class type = null;
if (
obj instanceof
ClassIdentifier )
type = ((
ClassIdentifier)
obj).
getTargetClass();
else
throw new
EvalError(
"Unknown class: "+
nameNode.
text, this,
callstack );
// Is an inner class style object allocation
boolean
hasBody =
jjtGetNumChildren() > 2;
if (
hasBody )
{
BSHBlock body = (
BSHBlock)
jjtGetChild(2);
if (
type.
isInterface() )
return
constructWithInterfaceBody(
type,
args,
body,
callstack,
interpreter );
else
return
constructWithClassBody(
type,
args,
body,
callstack,
interpreter );
} else
return
constructObject(
type,
args,
callstack );
}
private
Object constructObject(
Class type,
Object[]
args,
CallStack callstack )
throws
EvalError
{
Object obj;
try {
obj =
Reflect.
constructObject(
type,
args );
} catch (
ReflectError e) {
throw new
EvalError(
"Constructor error: " +
e.
getMessage(), this,
callstack );
} catch(
InvocationTargetException e) {
// No need to wrap this debug
Interpreter.
debug("The constructor threw an exception:\n\t" +
e.
getTargetException());
throw new
TargetError(
"Object constructor",
e.
getTargetException(),
this,
callstack, true);
}
String className =
type.
getName();
// Is it an inner class?
if (
className.
indexOf("$") == -1 )
return
obj;
// Temporary hack to support inner classes
// If the obj is a non-static inner class then import the context...
// This is not a sufficient emulation of inner classes.
// Replace this later...
// work through to class 'this'
This ths =
callstack.
top().
getThis( null );
NameSpace instanceNameSpace =
Name.
getClassNameSpace(
ths.
getNameSpace() );
// Change the parent (which was the class static) to the class instance
// We really need to check if we're a static inner class here first...
// but for some reason Java won't show the static modifier on our
// fake inner classes... could generate a flag field.
if (
instanceNameSpace != null
&&
className.
startsWith(
instanceNameSpace.
getName() +"$")
)
{
try {
ClassGenerator.
getClassGenerator().
setInstanceNameSpaceParent(
obj,
className,
instanceNameSpace );
} catch (
UtilEvalError e ) {
throw
e.
toEvalError( this,
callstack );
}
}
return
obj;
}
// TODO
/*
This is totally broken...
need to construct a real inner class block here...
*/
private
Object constructWithClassBody(
Class type,
Object[]
args,
BSHBlock block,
CallStack callstack,
Interpreter interpreter )
throws
EvalError
{
//throw new InterpreterError("constructWithClassBody unimplemented");
String name =
callstack.
top().
getName() + "$" + (++
innerClassCount);
Modifiers modifiers = new
Modifiers();
modifiers.
addModifier(
Modifiers.
CLASS, "public" );
Class clas;
try {
clas =
ClassGenerator.
getClassGenerator() .
generateClass(
name,
modifiers, null/*interfaces*/,
type/*superClass*/,
// block is not innerClassBlock here!!!
block, false/*isInterface*/,
callstack,
interpreter );
} catch (
UtilEvalError e ) {
throw
e.
toEvalError( this,
callstack );
}
try {
return
Reflect.
constructObject(
clas,
args );
} catch (
Exception e ) {
if (
e instanceof
InvocationTargetException )
e = (
Exception)((
InvocationTargetException)
e)
.
getTargetException();
if (
Interpreter.
DEBUG )
e.
printStackTrace();
throw new
EvalError(
"Error constructing inner class instance: "+
e, this,
callstack
);
}
}
private
Object constructWithInterfaceBody(
Class type,
Object[]
args,
BSHBlock body,
CallStack callstack,
Interpreter interpreter )
throws
EvalError
{
NameSpace namespace =
callstack.
top();
NameSpace local = new
NameSpace(
namespace, "AnonymousBlock");
callstack.
push(
local);
body.
eval(
callstack,
interpreter, true/*overrideNamespace*/ );
callstack.
pop();
// statical import fields from the interface so that code inside
// can refer to the fields directly (e.g. HEIGHT)
local.
importStatic(
type );
try {
return
local.
getThis(
interpreter).
getInterface(
type );
} catch (
UtilEvalError e ) {
throw
e.
toEvalError( this,
callstack );
}
}
private
Object objectArrayAllocation(
BSHAmbiguousName nameNode,
BSHArrayDimensions dimensionsNode,
CallStack callstack,
Interpreter interpreter
)
throws
EvalError
{
NameSpace namespace =
callstack.
top();
Class type =
nameNode.
toClass(
callstack,
interpreter );
if (
type == null )
throw new
EvalError( "Class " +
nameNode.
getName(
namespace)
+ " not found.", this,
callstack );
return
arrayAllocation(
dimensionsNode,
type,
callstack,
interpreter );
}
private
Object primitiveArrayAllocation(
BSHPrimitiveType typeNode,
BSHArrayDimensions dimensionsNode,
CallStack callstack,
Interpreter interpreter
)
throws
EvalError
{
Class type =
typeNode.
getType();
return
arrayAllocation(
dimensionsNode,
type,
callstack,
interpreter );
}
private
Object arrayAllocation(
BSHArrayDimensions dimensionsNode,
Class type,
CallStack callstack,
Interpreter interpreter )
throws
EvalError
{
/*
dimensionsNode can return either a fully intialized array or VOID.
when VOID the prescribed array dimensions (defined and undefined)
are contained in the node.
*/
Object result =
dimensionsNode.
eval(
type,
callstack,
interpreter );
if (
result !=
Primitive.
VOID )
return
result;
else
return
arrayNewInstance(
type,
dimensionsNode,
callstack );
}
/**
Create an array of the dimensions specified in dimensionsNode.
dimensionsNode may contain a number of "undefined" as well as "defined"
dimensions.
<p>
Background: in Java arrays are implemented in arrays-of-arrays style
where, for example, a two dimensional array is a an array of arrays of
some base type. Each dimension-type has a Java class type associated
with it... so if foo = new int[5][5] then the type of foo is
int [][] and the type of foo[0] is int[], etc. Arrays may also be
specified with undefined trailing dimensions - meaning that the lower
order arrays are not allocated as objects. e.g.
if foo = new int [5][]; then foo[0] == null //true; and can later be
assigned with the appropriate type, e.g. foo[0] = new int[5];
(See Learning Java, O'Reilly & Associates more background).
<p>
To create an array with undefined trailing dimensions using the
reflection API we must use an array type to represent the lower order
(undefined) dimensions as the "base" type for the array creation...
Java will then create the correct type by adding the dimensions of the
base type to specified allocated dimensions yielding an array of
dimensionality base + specified with the base dimensons unallocated.
To create the "base" array type we simply create a prototype, zero
length in each dimension, array and use it to get its class
(Actually, I think there is a way we could do it with Class.forName()
but I don't trust this). The code is simpler than the explanation...
see below.
*/
private
Object arrayNewInstance(
Class type,
BSHArrayDimensions dimensionsNode,
CallStack callstack )
throws
EvalError
{
if (
dimensionsNode.
numUndefinedDims > 0 )
{
Object proto =
Array.
newInstance(
type, new int [
dimensionsNode.
numUndefinedDims] ); // zeros
type =
proto.
getClass();
}
try {
return
Array.
newInstance(
type,
dimensionsNode.
definedDimensions);
} catch(
NegativeArraySizeException e1 ) {
throw new
TargetError(
e1, this,
callstack );
} catch(
Exception e ) {
throw new
EvalError("Can't construct primitive array: " +
e.
getMessage(), this,
callstack);
}
}
}