Of course the CLASSPATH form (non underscore version) is what people use now.
But I thought it used to also accept CLASS_PATH, maybe way back in the early 2000's?
I've Google'd around but haven't seen this answered. Google has trouble with this type of search, given the abundance of classpath, class and path in relation to Java. There are some older posts showing it as CLASS_PATH, and the one person who actually asked about the two versions didn't get a real answer on that board.
I was also wondering if maybe it was specific to one old JVM variant, or maybe to an early DOS / Windows port?
Obviously not a high priority, but was curious if anybody else remembered this, and whether there was ever any "official" support (or withdrawal) for it.
Thanks, Mark
You got me curious too - I found one reference googling "CLASS_PATH Gosling", the java faq in version 0.9.7. I can faintly remember (or I´m imagining) using it...
http://journals.ecs.soton.ac.uk/java/javafaq.html#xtocid558364
Searching on Google with quotes around CLASS_PATH ("CLASS_PATH") will certainly help your searches for this. That said, I've never seen this - except in some batch files used to start programs which passed this to java's command line argument.
Related
This question is related to an issue raised for Maven, which doesn't seem to escape paths forwarded to argument files supported by the JavaDoc-tool on Windows. The problem is that it's unclear from the documentation of JavaDoc itself how paths under Windows should be provided in those files.
The following is for Java 7:
If a filename contains embedded spaces, put the whole filename in double quotes, and double each backslash ("My Files\Stuff.java").
https://docs.oracle.com/javase/7/docs/technotes/tools/windows/javadoc.html#argumentfiles
The following from Java 8:
If a file name contains embedded spaces, then put the whole file name in double quotation marks.
https://docs.oracle.com/javase/8/docs/technotes/tools/windows/javadoc.html
In docs of Java 11 that part is completely missing, no mention of quotes, spaces or backslashes anymore:
https://docs.oracle.com/en/java/javase/11/javadoc/javadoc-command.html#GUID-EFE927BC-DB00-4876-808C-ED23E1AAEF7D
If you have a look at the URIs, in former versions of Java they were Windows-specific, while the last one is not. So I guess things have been refactored and some details of the argument files have been simply lost.
So, I need a place where I can talk to people about those differences in the documentation AND in the end how things are supposed to work on Windows. If backslash is an escape character in paths only and all that stuff. I would simply like to get some awareness from people who might know why the docs lack some details now and maybe even provide those details again.
So who/where do I write to? I don't know if it's Oracle or the OpenJDK project or someone completely different. Thanks!
I think, but don't take that authoritatively too lightly, that the javadoc tool is just an optional tool (can anyone show a formal obligation for any JDK to include a javadoc tool implementation ?) with a kind of de-facto standard set by the original owners, Sun thence Oracle.
But de-facto is only de-facto. Meaning formally and strictly speaking, that no JDK implementer has any obligation to make his javadoc tool behave like all the others do.
I think the best two places are the javadoc-dev mailinglist as well as the bugs database. Starting at some point in time (9, I guess) the have unified the parsing of the #files across tools. I have failed to find the code in the Mercurial repo last time.
I've been having terrible luck trying to get this to work, so I'm hopeful someone can help here.
In Java, I need to be able to take an HTML page with JavaScript within it and detect any JavaScript errors without, preferably without executing the JavaScript code.
I found this article:
Javascript parser for Java
And I've attempted to figure out how I'm supposed to use Caja to do this, but I'm having a difficult time finding any documentation with working examples of anything close to what I'm doing.
As a result I took a look at Nashorn also referenced in that article. I found a few examples which show how to execute JavaScript code from Java, but this doesn't process the whole HTML page. Even then, the execution doesn't seem to include the ability to validate common JavaScript functions (e.g. It hadn't heard of "alert").
Can anyone recommend something that might be able to do what I want, and point me in the right direction for their documentation or give me an example?
jshint as a standalone product seems to be a good fit for this:
it can run in java inside rhino (see https://github.com/jshint/jshint/)
a nodejs package exists (see https://www.npmjs.com/package/jshint)
it works with nashorn but it's quite tricky
I will only cover the technical difficulties around 3rd solution as I finally managed to make it work too...
Spoiler alert: "alert()" is not detected yet... Solution nb 2 will help there...
You first need to grab this specific release of jshint: https://github.com/jshint/jshint/releases/tag/2.4.4
Anything later than v2.7.0 will fail for now and I personally gave up patching intensively prototypes and namespaces... Releases from v2.4.4 until v2.6.3 work without modification but are limited in functionalities.
In the release notes, it's specifically written that "support for the Nashorn JavaScript engine" is working on this release. I'm using JDK8 nashorn 1.8.0_45 for this test.
Next step is to extract from this release this single file jshint-2.4.4/dist/jshint-rhino.js
Now you need to run nashorn/jjs in scripting mode and you need to be specific about the single file you wish to verify. In solution 2 (nodejs based) you can do multiple files or a complete hierarchy below a folder...
Create a simple file file.js:
function(){}
Now run the following command (please note the presence of -- ):
jjs -scripting jshint-rhino.js -- file.js
This will give you the following output:
Missing name in function declaration. (file.js:1:9)
> function(){}
So this covers the how to run jshint in a simple manner with nashorn... With the 3rd solution, at least you can find missing semicolons and several typical errors. But it's not a silver bullet and to me it's not a real alternative.
My personal preference would be to stick to solution 2 only. If you've the possibility to install either nodejs or iojs on your dev platform, go and grab https://www.npmjs.com/package/jshint. Not only will you be able to do more than the 3rd solution, you'll also be able to configure a jshintrc file as described at http://jshint.com/docs/
I am trying to create a simple server program to handle http requests. So with minimum search, I stumbled upon the oracle documentation for the httpserver class, inside the com.sun.net package. I'm relatively new to Java, so I thought that a class "sponsored" by Oracle itself would be included in the default libraries.
Unfortunately, that was not the case. After a lot of trials for possible syntax-import errors (various kinds of error arouse) and having installed the Oracle JDK 8 correctly on my Ubuntu machine, the compiler said that the package did not exist. What do I have to do to get the package to work?
I did finally make it work. Mostly, it was a misunderstanding from my place, since I only imported up to a point that was wrong - that is,I only imported com.sun.net.httpserver, thinking the latter part was the actual class I wanted, but it was merely the package name. So then I proceeded to import com.sun.net.httpserver.HttpServer, then the rest of my classes. Finally a com.sun.net.httpserver.* would work perfectly fine. It seems stupid now that I figured it out, but I think I will leave it here just in case anyone has the same misunderstanding - I already see 1 favourite on the question. And of course, as others have pointed out, the package is not part of the standard java libraries, but I used Oracle Java specifically for that.
P.S. The class is really useful, unlike what the other answer implies, but now I have stumbled upon another problem regarding reading the request body right, something that might have to do with the locale of the client-server, and I will now procced to search that.. Just a warning for anyone thinking of using the package.
Firstly try to avoid com.sun.xxx package, as those are internalls of Oracle/Sun java implementation.
Secondly, why not use libraries from apache ? See https://hc.apache.org/
EDITED:
You can also look on http://sparkjava.com/ , not tested but examples looks promising and they are using Java 8 nice features.
Is there a way to get put the cursor in a Java keyword and get help for that keyword? I know it works for apis, but what about the language itself.
I found a feature request for this at https://bugs.eclipse.org/bugs/show_bug.cgi?id=197903
Not without some plugin (if any even exists). Maybe just check official documentation (ex. http://docs.oracle.com/javase/tutorial/java/nutsandbolts/_keywords.html as a starting point). There really arent that many keywords, and they are fixed (at least per version, unlike classes, methods, etc.). Wikipedia has a page that also includes a brief summary at http://en.wikipedia.org/wiki/List_of_Java_keywords#List.
I'm writing java code using scala one (Kafka api), and I can't get eclipse to get the argument names in methods autocompletion, it's instead suggesting things like Method(String arg0, int arg1,...)
The source is apparently found correctly, as I can browse into it with F12, and I see the correct argument names, but it's still a bit tedious to go into every function, retrieve the argument names, and write the call after that.
I've installed the scala plugin for eclipse, which did not solve this.
Is is possible to solve this ? If yes, how ?
Thanks !
I had come across this issue a while ago and was figuring out how to fix it. Eventually used this plugin. You should take a look at his. https://stackoverflow.com/a/15520267/614867