Develop Reference

Netbeans v11.2 and Oracle JDK13 javadocs issues

I'm running NB 11.2 with Oracle JDK 13.0.1+9
NB's Java Platform ->> Javadocs (tab) is empty (no entries).
When I type (NB editor) java.math. -or- java.nio. (examples), pop-open menus shows methods AND the full javadoc info for each method as expected.
But when I type java.sql. -or- java.rmi. (examples), I get the methods listed, BUT Javadoc shows just the package and class definition and a message ((THE MESSAGE)) that reads:
Javadoc not found. Either Javadoc documentation for this item does not exist or you have not added specified Javadoc in the Java Platform Manager or the Library Manager.
Here's a screenshot:
So I added this URL to the Java Platforms ->> Javadocs tab:
https://docs.oracle.com/en/java/javase/13/docs/api/
No help...same problem.
So I added this URL Java Platforms ->> Javadocs tab:
https://docs.oracle.com/en/java/javase/13/docs/api/java.sql/
Now, the results changed, but still wrong. I've lost THE MESSAGE, but the package and class def shows with all blank text afterwards.
If this isn't a bug in NB/Oracle URL, then it seems very poorly documented which is evidenced by the sheer number of questions asked on SO.
Also, I'd like to download the whole javadoc .zip file and use a file ref instead of a URL. Is this still possible?

I'm running NB 11.1 with Oracle JDK 13.0.1+9...
That's a problem in itself. While it may appear to work, NetBeans 11.1 does not support the use of JDK 13. From the Product Manager for NetBeans: "Apache NetBeans 11.1 supports JDK 8 to JDK 12". Unfortunately I can't see this being explicitly stated anywhere on the Apache NetBeans web site.
So to successfully access Javadocs for JDK 13 in your applications:
Download and install Apache NetBeans 11.2.
In NetBeans 11.2, use Tools > Java Platforms to add JDK 13.
Follow the instructions below to install a local copy of the Javadoc for JDK 13.
Also, I'd like to download the whole javadoc .zip file and use a file
ref instead of a URL. Is this still possible?
Yes:
You can download the JDK 13 API Javadoc file jdk-13.0.1_doc-all.zip from here.
There no need to unzip the downloaded file.
In NetBeans 11.2 open Tools > Java Platforms > select your JDK 13 platform entry.
Click the Javadoc tab then click Add Zip/Folder...
Navigate to the downloaded file jdk-13.0.1_doc-all.zip, select it, then click Add Zip/Folder...
An entry for it will be added in the Platfrom Javadoc list. Remove any https URLs you had added previously, so that it is the only Javadoc entry for JDK 13:
Once you have done all that, Javadoc should work fine for your JDK 13 applications. Here's an example using java.rmi package which was not working for you:

Intellij Idea. I cannot see javadoc in source code

Before moving to Ubuntu I used IntelliJ on Windows. When I used ctrl + left click IDE showed me implementation with comment description above each method and class. But now implementation is shown without comments. How can I set that?

It depends if the class you're looking at also has sources attached, either through the IDE or through your dependency manager. If there are no sources available, then all you can receive is the decompiled version.
You will have to attach sources to the library you wish if you want to see the full implementation.

I cleared it up. The point was that I installed OpenJDK from default set Ubuntu repositories that doesn't have sources attached. The solution was to install official Oracle JDK like I did before. To do it, add Oracle's repository to your system and install jdk: https://tecadmin.net/install-oracle-java-8-ubuntu-via-ppa/

link the Doxygen documentation with a Java project inside Eclipse?

Could you tell me how to link the doxygen documentation with a Java project inside Eclipse?
Here is the background: I am involved in a C++ project, which has a Java Interface. Its document seems to be generated by doxygen rather than javadoc. I hope to use this documentation inside Eclipse, but I don't see how to. I have installed the doxygen plugin Eclox but apparently I don't see what to do next.
For information, here is the a part of my project's ./doc directory./doc

Javadoc not Found [duplicate]

Right now when I use a built in method, it shows me the returns types and nothing else that's useful.
Is there something I can download to make the info from the intellisense more robust?
Javadoc not found. Either Javadoc
documentation for this item does not
exist or you have not added specified
Javadoc in the Java Platform Manager
or the Library Manager.

You need to download the JDK API docs, which you can get from this page.
Then in NetBeans, go to Tools -> Java Platforms -> Javadoc to specify the directory where you downloaded them.

The javadocs come in the jdk package or at least in JDK 1.8. You can add the zip files named src.zip and javafx-src.zip to the tools>java platform>Javadoc.

Enabling full documentation for Java EE in eclipse

I'm new to Eclipse and am using it currently to play with Java EE.
When using Ctrl+Space for types/functions from the regular Java libraries I get a full description (i.e. general description of the type, what are the arguments of the method for, etc.). However I don't get the same for Java EE types.
For example, when using Ctrl+Space on methods of the HttpSession class I get only names like "arg0" or "obj" and no description.
How can I remedy this?

I'd suggest downloading the javadocs and adding them in eclipse. (right click project > properties > java build path > libraries > expand the library > set Javadoc location)

I think that's why Java EE defines a specification only, the implementation must then be done by the provider of your application server. javax.servlet.http.HttpSession e.g. is bundled in servlet.jar.
It you are using Tomcat as your application server, you could attach the java sources to your servlet.jar and then you can browse the source and read it's javadoc.
The source for the latest tomcat is here ->
http://www.apache.org/dist/tomcat/tomcat-6/v6.0.26/src/apache-tomcat-6.0.26-src.zip

I wanted to add what might be very pertinent information for projects using maven and eclipse / wtp. What I did to get the Javadocs to attach nicely was the following 2 steps.
1) I am using glassfish so using the glassfish plugin site I installed the java ee 6 (or 7) documentation. You can easily view this documentation with Help->Java EE 6 docs. I copied the URL from here.
2) Opened my projects build path and went to the libraries tab. Opened the Maven Dependencies and found the java ee 6 api entry (this should be part of the maven project). Opened this up and was able to add a location for the javadocs for the api. I pasted the file:/// url I had copied.
Then I verified this worked by using the ctrl + shift plus mouse pointer hover over some of the java ee 6 classes and methods.
I hope this information will be useful to other who searched and got here but didn't find the solution they were looking for (or for those who now use Maven!).