Trouble using java class within jruby - java

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 :).

Related

apache PIG with datafu: Cannot resolve UDF's

I'm trying the quickstart from here: http://datafu.incubator.apache.org/docs/datafu/getting-started.html
I tried nearly everything, but I'm sure it must be my fault somewhere. I tried already:
exporting PIG_HOME, CLASSPATH, PIG_CLASSPATH
starting pig with -cpdatafu-pig-incubating-1.3.0.jar
registering datafu-pig-incubating-1.3.0.jar locally and in hdfs => both succesful (at least no error shown)
nothing helped
Trying this on pig:
register datafu-pig-incubating-1.3.0.jar
DEFINE Median datafu.pig.stats.StreamingMedian();
data = load '/user/hduser/numbers.txt' using PigStorage() as (val:int);
data2 = FOREACH (GROUP data ALL) GENERATE Median(data);
or directly
data2 = FOREACH (GROUP data ALL) GENERATE datafu.pig.stats.StreamingMedian(data);
I get this name-resolve error:
2016-06-04 17:22:22,734 [main] ERROR org.apache.pig.tools.grunt.Grunt
- ERROR 1070: Could not resolve datafu.pig.stats.StreamingMedian using imports: [, java.lang., org.apache.pig.builtin.,
org.apache.pig.impl.builtin.] Details at logfile:
/home/hadoop/pig_1465053680252.log
When I look into the datafu-pig-incubating-1.3.0.jar it looks OK, everything in place. I also tried some Bag functions, same error then.
I think it's kind of a noob-error which I just don't see (as I did not find particular answers for datafu in SO or google), so thanks in advance for shedding some light on this.
Pig script is proper, the only thing that could break is that while registering datafu there were some class dependencies that coudn't been met.
Try to run locally (pig -x local) and see a detailed log.
Check also the version of pig - it should be newer than 0.14.0.

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.

Undefined objects in JavaScript engine in 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.

Why doesn't printStackTrace work in Clojure?

In both the Joy of Clojure and on Alex Miller's Pure Danger Tech blog-post it is recommended that you can print the last stack using something like the following:
(use 'clojure.stacktrace)
(java.util.Date. "foo")
(.printStackTrace *e 5)
But I can't get any of their examples to work, and instead just get
java.lang.NullPointerException: null
Reflector.java:26 clojure.lang.Reflector.invokeInstanceMethod
(Unknown Source) jtown$eval9755.invoke
What's up with this? .printStackTrace seems to be a Java function from the looks of it, so I am not sure why I am bringing clojure.stacktrace into my namespace, in the first place. I read through the clojure.stacktrace API, though, and see an e function, which seems similar too but is not the *e function, which is in core and is supposed to be binding to the last exception, but isn't. Could somebody straighten me out on the best way to check stack-traces?
There are some special vars available when using the REPL and
*e - holds the result of the last exception.
For instance:
core=> (java.util.Date. "foo")
IllegalArgumentException java.util.Date.parse (Date.java:615)
core=> (class *e)
java.lang.IllegalArgumentException
core=> (.printStackTrace *e)
java.lang.IllegalArgumentException
at java.util.Date.parse(Date.java:615)
<not included.....>
You are right, .printStackTrace is the java method that is invoked on the exception class. This is not very straightforward (since its java interop) so clojure.stacktrace namespace has some utilities about working with stack traces
So after
(use 'clojure.stacktrace)
you can use the stacktrace library instead of java interop:
core=> (print-stack-trace *e)
java.lang.IllegalArgumentException: null
at java.util.Date.parse (Date.java:615)
<not included.....>
Obviously in an app, instead of *e, you can do a try - catch and use the related functions as necessary
I use
(.printStackTrace *e *out*)
That seems to work.

No Such method error during transformation to pdf in Java

I have a problem while transforming the xslt to pdf in java, i am following the same process posted in this link
"Java Transformation to PDF".
Error:
`
Caused by: java.lang.NoSuchMethodError: org.apache.xmlgraphics.java2d.GraphicContext.<init>(Lorg/apache/xmlgraphics/java2d/GraphicContext;)V
at org.apache.fop.render.intermediate.IFGraphicContext.<init>(IFGraphicContext.java:50)
at org.apache.fop.render.intermediate.IFGraphicContext.clone(IFGraphicContext.java:56)
at org.apache.fop.render.intermediate.IFRenderer.saveGraphicsState(IFRenderer.java:632)
at org.apache.fop.render.intermediate.IFRenderer.startViewport(IFRenderer.java:885)
at org.apache.fop.render.intermediate.IFRenderer.startVParea(IFRenderer.java:878)
at org.apache.fop.render.AbstractRenderer.renderRegionViewport(AbstractRenderer.java:289)
at org.apache.fop.render.intermediate.IFRenderer.renderRegionViewport(IFRenderer.java:731)
at org.apache.fop.render.AbstractRenderer.renderPageAreas(AbstractRenderer.java:249)
at org.apache.fop.render.AbstractRenderer.renderPage(AbstractRenderer.java:230)
at org.apache.fop.render.intermediate.IFRenderer.renderPage(IFRenderer.java:580)
at org.apache.fop.area.RenderPagesModel.addPage(RenderPagesModel.java:114)
at org.apache.fop.layoutmgr.AbstractPageSequenceLayoutManager.finishPage(AbstractPageSequenceLayoutManager.java:312)
at org.apache.fop.layoutmgr.PageSequenceLayoutManager.finishPage(PageSequenceLayoutManager.java:167)
at org.apache.fop.layoutmgr.PageSequenceLayoutManager.activateLayout(PageSequenceLayoutManager.java:109)
at org.apache.fop.area.AreaTreeHandler.endPageSequence(AreaTreeHandler.java:238)
at org.apache.fop.fo.pagination.PageSequence.endOfNode(PageSequence.java:120)
at org.apache.fop.fo.FOTreeBuilder$MainFOHandler.endElement(FOTreeBuilder.java:349)
at org.apache.fop.fo.FOTreeBuilder.endElement(FOTreeBuilder.java:177)
at net.sf.saxon.event.ContentHandlerProxy.endElement(ContentHandlerProxy.java:391)
at net.sf.saxon.event.ProxyReceiver.endElement(ProxyReceiver.java:174)
at net.sf.saxon.event.NamespaceReducer.endElement(NamespaceReducer.java:213)
at net.sf.saxon.event.ComplexContentOutputter.endElement(ComplexContentOutputter.java:417)
at net.sf.saxon.instruct.ElementCreator.processLeavingTail(ElementCreator.java:301)
at net.sf.saxon.instruct.Block.processLeavingTail(Block.java:409)
at net.sf.saxon.instruct.Instruction.process(Instruction.java:94)
at net.sf.saxon.instruct.ElementCreator.processLeavingTail(ElementCreator.java:298)
at net.sf.saxon.instruct.Template.applyLeavingTail(Template.java:175)
at net.sf.saxon.instruct.ApplyTemplates.applyTemplates(ApplyTemplates.java:343)
at net.sf.saxon.Controller.transformDocument(Controller.java:1736)
at net.sf.saxon.Controller.transform(Controller.java:1560)
at mypackage.v2.business.pdf.XMLtoPDF.convertXMLPDF(XMLtoPDF.java:103)
... 51 more
java.lang.ClassCastException: java.lang.NoSuchMethodError cannot be cast to java.lang.Exception
`
Please let me know what could be the problem.
As described in the documentation
Thrown if an application tries to call a specified method of a class (either static or instance), and that class no longer has a definition of that method.
Here's how this can happen. Imagine you built some code that used a library with a method called foo(). You compiled your project and then later decided to upgrade the library. You do this by overwriting the old jar file with the new one. You don't recompile your code.
But what you didn't know is the new library removed the foo() method. Now if you run your code, it will throw this exception because your compile code calls this method and it's no longer there.
In your specific case, this isn't necessarily your code with the problem. It could be that you have one library that uses another library and the problem is there (for example, Library X uses version 2 of Library Y, but you only have Library Y version 1 in your classpath). If this is happening, you need to make sure the libraries are using the version they expect.
For your specific problem, you need to find the version of the jar that has org.apache.xmlgraphics.java2d.GraphicContext in it and it needs to have a constructor that takes a... list of org/apache/xmlgraphics/java2d/GraphicContext... maybe. I forget what (L...;)V means.

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