Undefined objects in JavaScript engine in Java - java

Executing the following code in Java7
ScriptEngine scriptEngine = new ScriptEngineManager().getEngineByName("js");
Bindings b = scriptEngine.createBindings();
b.put("x", true);
scriptEngine.eval("x&y", b);
I get the error
sun.org.mozilla.javascript.internal.EcmaError: ReferenceError: "b" is not defined. (<Unknown Source>#1) in <Unknown Source> at line number 1
Is there an option to evaluate to null/false for undefined objects, like in JavaScript?
I know that an option will be to do something like "this.x&this.y" instead of "x&y", but I don't have control over that string (user entered).

I browsed a little bit through the Rhino code and it seems that there's no such option.
In the end I will append "this." in front of each variable. This is not by far a desirable solution (I will not even accept my own answer :) ), but for the time being I have no other.

Related

Error in ColdFusion Javacast array to class from loadPaths

I am trying to use Elasticsearch's Java API.
I am trying to create a RestClientBuilder.
Host=createObject("java", "org.apache.http.HttpHost").init(variables.HostName, variables.Port);
Node=createObject("java", "org.elasticsearch.client.Node").init(Host);
RestClient=createObject("java", "org.elasticsearch.client.RestClient").builder(Javacast("org.elasticsearch.client.Node[]", [Node])).build();
I get the error
Cannot convert the value to Java array because type org.elasticsearch.client.Node is unknown.
Also if I just try to use:
RestClient=createObject("java", "org.elasticsearch.client.RestClient").builder(Javacast("org.apache.http.HttpHost[]", [Host]));
I get the following error
Either there are no methods with the specified method name and
argument types or the builder method is overloaded with argument types
that ColdFusion cannot decipher reliably. ColdFusion found 0 methods
that match the provided arguments. If this is a Java object and you
verified that the method exists, use the javacast function to reduce
ambiguity.
This I assume is because ColdFusion doesn't play nicely with varargs
I found a workaround using this method
https://www.bennadel.com/blog/1980-tojava---a-coldfusion-user-defined-function-for-complex-java-casting.htm
I believe there is a bug with Javacast and javaSettings loadPaths not being used.
coldfusion.runtime.Cast$UnknownTypeException: Cannot convert the value
to Java array because type org.elasticsearch.client.Node is unknown.
at coldfusion.runtime.Cast.toJavaArray(Cast.java:1602)
Additionally if I try to perform the actiuons that the UDF takes
local.javaClass = createObject("java", "org.apache.http.HttpHost");
local.HostArrayReflect = createObject("java", "java.lang.reflect.Array");
local.HostArray = local.HostArrayReflect.newInstance(
local.javaClass.GetClass()
, JavaCast( "int", ArrayLen(local.Hosts))
);
for (i=0; i LT ArrayLen(local.Hosts); i=i+1) {
local.HostArrayReflect.Set(local.HostArray, JavaCast("int", i), local.Hosts[i]);
}
I get the error
An exception occurred while instantiating a Java object. The class
must not be an interface or an abstract class. If the class has a
constructor that accepts an argument, you must call the constructor
explicitly using the init(args) method. Error :
org.apache.http.HttpHost
java.lang.NoSuchMethodException: org.apache.http.HttpHost.() at
java.lang.Class.getConstructor0(Class.java:3082) at
java.lang.Class.newInstance(Class.java:412) at
coldfusion.runtime.java.JavaProxy.createObjectWithDefaultConstructor(JavaProxy.java:209)
at coldfusion.runtime.java.JavaProxy.invoke(JavaProxy.java:92)
This happens when I try to run getClass(), but in the UDF there is no issue. A coworker tried to run this on Lucee and it seems to have worked, so I believe there is a bug in CF related to this.

Why does Java 8's Nashorn engine in strict mode throw a java.lang.ClassCastException when calling apply() and passing the arguments object directly?

When I call eval (in strict mode) on a nashorn engine with the following script I get an exception:
var yfunc = function () {
(null).apply(null, arguments);
};
yfunc();
I've truncated my personal situation heavily. The "(null)" on line 2 can be replaced with anything between parenthesis or a local variable, either way just something that shouldn't throw a compile error, and it will yield the same result.
The issue seems to be explicitly that "arguments" is passed directly as the second argument of calling a method called "apply". Any of the following changes will undo the thrown exception:
Putting "arguments" in a variable first (but simply wrapping it in parenthesis doesn't work!)
Calling something other than apply
Passing "arguments" in a different argument slot when calling apply
Calling print() (with or without passing any arguments) as a preceding line of code inside yfunc() (weird huh?)
Defining more than 0 parameters for yfunc()
Binding yfunc first and then calling the bound method
Calling yfunc via Function.apply (not so much with Function.call!)
The Exception thrown is this:
Exception in thread "main" java.lang.ClassCastException: Cannot cast jdk.nashorn.internal.runtime.Undefined to jdk.nashorn.internal.runtime.ScriptFunction
at java.lang.invoke.MethodHandleImpl.newClassCastException(MethodHandleImpl.java:361)
at java.lang.invoke.MethodHandleImpl.castReference(MethodHandleImpl.java:356)
at jdk.nashorn.internal.scripts.Script$\^eval\_.:program(<eval>:4)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:637)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:494)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:393)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:449)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:406)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:402)
at jdk.nashorn.api.scripting.NashornScriptEngine.eval(NashornScriptEngine.java:155)
at javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:264)
When I call this method with an owner, the exception thrown changes. Example code:
var yfunc = {
method: function () {
(null).apply(null, arguments);
}
};
var x = yfunc.method();
Then the thrown exception looks like this:
Exception in thread "main" java.lang.ClassCastException: Cannot cast jdk.nashorn.internal.scripts.JO4 to jdk.nashorn.internal.runtime.ScriptFunction
at java.lang.invoke.MethodHandleImpl.newClassCastException(MethodHandleImpl.java:361)
at java.lang.invoke.MethodHandleImpl.castReference(MethodHandleImpl.java:356)
at jdk.nashorn.internal.scripts.Script$\^eval\_.:program(<eval>:5)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:637)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:494)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:393)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:449)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:406)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:402)
at jdk.nashorn.api.scripting.NashornScriptEngine.eval(NashornScriptEngine.java:155)
at javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:264)
I've reproduced the issue so far on specifically these environments:
windows 7 64bit -> jdk 1.8.0_60 64bit
windows 8 64bit -> jdk 1.8.0_131 64bit
I can't seem to find anything on the internet about similar issues. Do I need to report this to Oracle/OpenJDK?
Minor update
Added items 6 and 7 to list of "following changes will undo the thrown exception".
Final update
Bug filed: JDK-8184720
Yes, it appears to be a bug. Please file a bug.

Run an ABCL code that uses cl-cppre

With reference to my previous question,
Executing a lisp function from Java
I was able to call lisp code from Java using ABCL.
But the problem is, the already existing lisp code uses CL-PPCRE package.
I can not compile the code as it says 'CL-PPCRE not found'.
I have tried different approaches to add that package,
including
1) how does one compile a clisp program which uses cl-ppcre?
2)https://groups.google.com/forum/#!topic/cl-ppcre/juSfOhEDa1k
Doesnot work!
Other thing is, that executing (compile-file aima.asd) works perfectly fine although it does also require cl-pprce
(defpackage #:aima-asd
(:use :cl :asdf))
(in-package :aima-asd)
(defsystem aima
:name "aima"
:version "0.1"
:components ((:file "defpackage")
(:file "main" :depends-on ("defpackage")))
:depends-on (:cl-ppcre))
The final java code is
interpreter.eval("(load \"aima/asdf.lisp\")");
interpreter.eval("(compile-file \"aima/aima.asd\")");
interpreter.eval("(compile-file \"aima/defpackage.lisp\")");
interpreter.eval("(in-package :aima)");
interpreter.eval("(load \"aima/aima.lisp\")");
interpreter.eval("(aima-load 'all)");
The error message is
Error loading C:/Users/Administrator.NUIG-1Z7HN12/workspace/aima/probability/domains/edit-nets.lisp at line 376 (offset 16389)
#<THREAD "main" {3A188AF2}>: Debugger invoked on condition of type READER-ERROR
The package "CL-PPCRE" can't be found.
[1] AIMA(1):
Can anyone help me?
You need to load cl-ppcre before you can use it. You can do that by using (asdf:load-system :aima), provided that you put both aima and cl-ppcre into locations that your ASDF searches.
I used QuickLisp to add cl-ppcre (because nothing else worked for me).
Here is what I did
(load \"~/QuickLisp.lisp\")")
(quicklisp-quickstart:install)
(load "~/quicklisp/setup.lisp")
(ql:quickload :cl-ppcre)
First 2 lines are only a one time things. Once quickLisp is installed you can start from line 3.

not enough java heap space' r programming

I am out of my R depth. I defined a function nGrams (using RWeka) that worked fine when I tried it out, and sometimes it still does. I do not know how to figure out what environment it works in, what environment I am in when I want to use it, etc. Any quick tips or can you point me to a webpage that could help? If I have to put in a change environment command every time I use it, that is just fine. I really do not understand the issue.
here is what I see in my console.
blog2gramfreq <- nGrams(cleanblogs100000, 2)
Error in ls(envir = envir, all.names = private) :
invalid 'envir' argument
Called from: top level
Called from: top level
Browse[1]>
structure(function (this, private = FALSE, ...)
{
envir <- attr(this, ".env")
ls(envir = envir, all.names = private)
}, export = FALSE, S3class = "Object", modifiers = "public")
I do see nGrams in my Global Environment window.
This was something that came up in a Coursera class blog that i did not find an answer to, at least for R. Here is an answer that worked for me when I received the "'OutOfMemoryError : not enough java heap space" error in R programming.
options(java.parameters="-Xmx4000m")

Trouble using java class within jruby

I'm trying to use Java Opencl from within jruby, but am encountering a problem which I can't solve, even with much google searching.
require 'java'
require 'JOCL-0.1.7.jar'
platforms = org.jocl.cl_platform_id.new
puts platforms.class
org.jocl.CL.clGetPlatformIDs(1, platforms, nil)
when I run this code using: jruby test.rb
I get the following error, when the last line is uncommented:
#<Class:0x10191777e>
TypeError: cannot convert instance of class org.jruby.java.proxies.ConcreteJavaP
roxy to class [Lorg.jocl.cl_platform_id;
LukeTest at test.rb:29
(root) at test.rb:4
Just wondering whether anyone has an idea on how to solve this problem?
EDIT:
ok so I think I've solved the first part of this problem by making platforms an array:
platforms = org.jocl.cl_platform_id[1].new
but that led to this error when adding the next couple of lines:
context_properties = org.jocl.cl_context_properties.new()
context_properties.addProperty(org.jocl.CL::CL_CONTEXT_PLATFORM, platforms[0])
CodegenUtils.java:98:in `human': java.lang.NullPointerException
from CodegenUtils.java:152:in `prettyParams'
from CallableSelector.java:462:in `argumentError'
from CallableSelector.java:436:in `argTypesDoNotMatch'
from RubyToJavaInvoker.java:248:in `findCallableArityTwo'
from InstanceMethodInvoker.java:66:in `call'
from CachingCallSite.java:332:in `cacheAndCall'
from CachingCallSite.java:203:in `call'
from test.rb:36:in `module__0$RUBY$LukeTest'
from test.rb:-1:in `module__0$RUBY$LukeTest'
from test.rb:4:in `__file__'
from test.rb:-1:in `load'
from Ruby.java:679:in `runScript'
from Ruby.java:672:in `runScript'
from Ruby.java:579:in `runNormally'
from Ruby.java:428:in `runFromMain'
from Main.java:278:in `doRunFromMain'
from Main.java:198:in `internalRun'
from Main.java:164:in `run'
from Main.java:148:in `run'
from Main.java:128:in `main'
for some reason when I print the class of platforms[0] it's listed as NilClass!?
You are overlooking a very simple mistake. You write
platforms = org.jocl.cl_platform_id.new
but that line creates a single instance of the class org.jocl.cl_platform_id. You then pass that as the second parameter to org.jocl.CL.clGetPlatformIDs in
org.jocl.CL.clGetPlatformIDs(1, platforms, nil)
and that doesn't work, because the second argument of the method requires an (empty) array of org.jocl.cl_platform_id objects.
What the error says is: "I have something that is a proxy for a Java object and I can't turn it into an an array of org.jocl.cl_platform_id objects, as you are asking me to do.
If you just say
platforms = []
and pass that in, it might just work :).

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