I know there are very many questions exactly like this, but I have tried various things and still have no idea what to do. I started learning java very recently and was just able to print "hello world" with a .java file using a text editor. That was when I decided to get an IDE and I downloaded NetBeans 12.0. Once netbeans was ready, I clicked "new project" and chose "Java with Maven" and "Java application". Once I finished setting up the project, I right clicked the package and made a new main class. However, next to "package com.mycompany.qwerty" in the file there was a red exclamation mark symbol where it shows the line numbers. When I put my mouse over it, it said "Cannot access java.lang Fatal error: unable to find package in classpath or bootclasspath". I have absolutely no idea how to fix this since I have never used NetBeans before. I have tried reinstalling netbeans several times and the same thing occurs. I have jdk 11.0.8 as well. How would I resolve this issue?
After reading sorifiend's comment, I looked up how to change the file path for jdk. In a file called netbeans.conf the variable called netbeans_jdkhome was just /usr or something and I changed it to /usr/lib/jvm/java-1.11.0-openjdk-amd64 (I have linux) and then the problem was completely fixed.
No matter what I do, I can't get Netbeans 11 to work with JDK 11. Can you help me out?
Please note that this issue does NOT occur with JDK 8.
Downloaded and installed JDK 11 to C:\Program Files\Java\jdk-11.0.4
Downloaded and unzipped Netbeans 11 to C:\Program Files\netbeans
The etc/netbeans.conf file has been edited to set JDK home:
netbeans_jdkhome="C:\Program Files\Java\jdk-11.0.4"
When trying to run bin/netbeans64.exe:
First time: The loading window appears, loads for a bit, and then the
whole program disappears.
Second time: Loading window does not appear. An empty Java application
appears.
If I go to Task Manager and manually end the Netbeans process, I can
get back to First time.
For the attachments listed below, please refer to the issue I created here:
https://issues.apache.org/jira/browse/NETBEANS-2865
Executing netbeans64.exe from PowerShell outputs error messages to the console. They can be found in consoleOutput.txt attachment.
The results from executing bin/netbeans64.exe --trace C:\netbeans.log can be found in netbeans.log attachment.
For reference, this is the tutorial I followed:
https://www.youtube.com/watch?v=cxh-hVty09g
Update & Solution
I FINALLY got it to work thanks to the answer provided by skomisa.
The issue was caused by Netbeans 11.0 importing settings from a previous version. There was a popup the first time I ran Netbeans 11.0 asking if I wanted to import my settings from a previous version. Refer to skomisa's answer for more details on why.
To solve it, I deleted ALL of the preference files for NetBeans 11 by deleting the entire folder in AppData.
C:\Users\Hunter\AppData\Roaming\NetBeans\11.0\
Skomisa's answer mentioned trying to create a new unzipped version of NetBeans 11 and not importing the settings. I had actually tried this previously, but never got the popup window asking if you want to import. I assume this is because the user preference files for this version of NetBeans have already been created and are still sitting in AppData.
This leaves you with two viable options:
Delete all of the user preference files for NetBeans 11.0.
Search through the entire folder for instances of \u0000 and remove them.
It seemed easier and more satisfactory to remove the entire folder and start from scratch. That way, all of my user preference files are using the newest practices accepted by the JDK and Netbeans and that, hopefully, there is no lingering legacy code that will randomly break the next time I update.
Thanks for everyone's help!
Your problem appears to be related to the IllegalArgumentException ("Key contains code point U+0000") in the console log output of your bug report. It looks like NetBeans is trying to import your preferences from an earlier release of Netbeans, and is is finding some invalid null character(s) in your preference file(s).
This has been bug reported before, but remains unresolved. See Bug 271652 - IllegalArgumentException: Key contains code point U+0000.
Your preference files are all XML files (with extension xml), and reside in various directories under C:\Users\user ID\AppData\Roaming\NetBeans\11.0\config.
In my case my only preference file for NetBeans 11 is named C:\Users\johndoe\AppData\Roaming\NetBeans\11.0\config\Editors\text\x-java\Preferences\org-netbeans-modules-editor-settings-CustomPreferences.xml but you may have more than one.
From the stack trace in your console log, the failing call is AbstractPreferences.getBoolean(), so the null is probably on a line containing Boolean in your preference file. However, as this somewhat related SO answer suggests, just blindly remove all nulls from all preference files. Nulls should never exist in any XML file anyway.
An alternative approach to solving your problem is to create a new unzipped version of NetBeans 11, but do not import your settings.
I suppose you could even locate the preference files in your existing (broken) NB 11 installation and delete them, though that seems like an unsatisfactory approach even if it works.
A few related points:
Seeing the NetBeans window appear briefly before it vanishes is often a symptom of having set netbeans_jdkhome to an invalid JDK path, but in your case the value looks fine.
JAVA_HOME is ignored by NetBeans, so that cannot be the cause of your problem. See the response to Bug 198950 - NetBeans should use the JAVA_HOME and JDK_HOME environment variables, if available, to determine which JDK to use for details on how NetBeans decides which JDK to use. Specifying the --jdkhome parameter when you start NetBeans will override everything else.
The IllegalArgumentException only arises with JDK versions >= 9 because of a JDK bug fix, but that's a good thing. See JDK-8075156 : (prefs) get*() and remove() should disallow the use of the null control character '\u0000' as key for details. You weren't getting the problem with NetBeans 8.x because you probably weren't ever importing any preference files, but even if you were the IllegalArgumentException would not have occurred due to the Java bug fixed by JDK-8075156.
I have set the jdk compliance level to 1.7 and the JRE version I am using is also set to 1.7.
But I am getting a red cross on index.jsp. What could be the reason for this ?
Though I can see the file running in the browser, eclipse's console doesn't show any error.
First make sure there really are no errors: Window -> Show View -> Other... -> Markers.
If there are none, sometimes Eclipse gets stuck thinking there are errors when there aren't. Close all editors, clean the project, close then reopen it in the project explorer (right-click on it), and see if the error clears.
I've also noticed that Eclipse has weird issues parsing JSP; sometimes it's confused and you just have to ignore it, but you could try opening the JSP file, selecting all, cutting, then pasting to force a recheck (or sometimes cut -> clean build -> paste).
I don't know why it does this, and I've been reading / filing bug reports for literally years, but it really seems to choke on JSP (something about the mix of HTML, Java, and JSP tags doesn't sit right with its parser).
Eclipse marks with this sign any file containing syntax errors (not compiling). If you don't have any syntax errors, then you should try cleaning up all your projects, as sometimes it may look inside old metadata files to determine whether there are errors in a given file.
I've downloaded, unzipped and setup Eclipse 3.4.2 with some plugins (noteable, EPIC, Clearcase, QuantumDB, MisterQ).
Now I find when I'm editing Java projects the code completion is not working. If I type String. and press ctrl+space a popup shows "No Default Proposals" and the status bar at the bottom shows "No completions available".
Any ideas?
Try restoring the default options in 'Windows > Preferences > Java > Editor > Content Assist > Advanced'
An example of the kind of data you see in this preference screen, however not necessarily what you currently have.
(From Vadim in this blog post " Content Assist Duplicates in Eclipse (Mylyn)":
if have duplicate Mylyn entries, uncheck the duplicate entries that do not contain "(Mylyn)" in their name)
The Eclipse help page defines the default list to restore:
Select the proposal kinds contained in the 'default' content assist list:
Other Java Proposals,
SWT Template Proposals,
Template Proposals,
Type Proposals
I'm adding an answer here in case someone else finds this on Google. Same symptoms; different problem. For me, the type caches had become corrupt.
From http://mschrag.blogspot.co.nz/2009/01/open-type-cant-find-your-class.html
Quit Eclipse
Go to workspace/.metadata/.plugins/org.eclipse.jdt.core
Remove *.index and savedIndexNames.txt
Restart Eclipse and search Ctrl+T for the offending type. The indexes will be rebuilt.
In case someone comes here and want to activate the autocomplete function, go to
Preferences -> Java -> Editor -> Content Assist.
Then in the Auto Activation section fill in Auto activation triggers for Java:
abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ._
For those running Xfce + having IBus plugin activated, there might be keyboard shortcut conflict.
See more info on my blog: http://peter-butkovic.blogspot.de/2013/05/keyboard-shortcut-ctrlspace-caught-in.html
UPDATE:
as suggested by #nhahtdh's comment, adding the some more info to answer directly: IBus plugin in Xfce uses by default Ctrl+Space shortcut for keyboard layout switching. To change it, go to: Options and change it to whatever else you prefer.
Check the lib of your project. It may be that you have include two such jar files in which same class is available or say one class in code can be refrenced in two jar files. In such case also eclipse stops assisting code as it is totally confused.
Better way to check this is go to the file where assist is not working and comment all imports there, than add imports one by one and check at each import if code-assist is working or not.You can easily find the class with duplicate refrences.
Another solution which worked for me is to go to Java--> Appearence --> Type Filters and do disable all
None of these worked for me.
I was experiencing this issue in only once particular class. What finally worked for me was to delete the offending class and recreate it. Problem solved... mystery not so much!
If you have installed Google Toolbar for IE, may be you can face the same problem. Because, the toolbar capture the shortcut ctrl+Space.
I had this problem and like #Marc, only on a particular class. I discovered that I needed to designate Open With = Java Editor. As a Eclipse newbie I hadn't even realized that I was just using a plain text editor.
In the package explorer, right-click the file and chose "Open With".
I faced this problem, and spent hours trying to figure out the issue. tried to follow the steps mentioned in the different answers above, the solution I found is on the same lines as Mona suggested, but slightly different. Tried to add as a comment to Mona's answer but no option was available.
Issue with my eclipse was, classpath somehow got corrupted and all the jars and dependent projects were missing. after taking the latest .classpath from repository it worked fine.
Check that you did not filter out many options inside the Window > Preferences > Java > Appearance > Type Filters
Items in this list will not be appear in quick fix, be autocompleted, or appear in other various places like the Open Type dialog.
I also face this issue but it is resolved in different way.
Steps that I follow may be helpful for others.
Right click on project (the one you are working on)
Go to Properties > Java Build Path > JRE System Library
Click Edit... on the right
Choose the JRE 7
Once you have you configuration checked and completion is still not working:
make sure you have the right directory structure.
Do you see the right icon beside the file?:
It will tell you how the file will be treated by Eclipse:
I am posting this answer as I had that story with with Maven webapp artifact. By default Maven-WebApp does not create folder for sources and I put my Java into resources, wondering for 5 minutes what was going on... :)
Running STS on Java Spring Boot projects, here's what works for me :
Maybe this helps other people who come across the same issue.
My setup: old Gradle project (version Gradle 2.12) made by someone else, imported using the Gradle Import Wizard into STS (Eclipse Oxygen.2 (4.7.2)).
Code completion did not work either (and I still have hollow Js at the Java files), but at least I got the code completion to work by doing:
right click on the project folder > Properties > Gradle > Configure Workspace Settings > Java > Editor > Content Assist > Advanced
check "Java Proposals in upper window.
2x Apply & Close
I have run into this problem since upgrading to Eclipse 2019-09. Based on some of the suggestions above, this is what worked for me.
I had to go to Eclipse -> Preferences -> Java -> Editor -> Content Assist -> Advanced.
I found out that if I turn on any of the key binding proposals, Java Non-Type, Java, Java (Task-Focused) or Java Type proposal, then I was able to use auto complete. If I turned them all on, then not only did auto complete work, but I got duplicate methods listed. I am guessing, but I will probably used Java Type Proposals. Any clarification of what differs for these four types would be appreciated.
In my case, Intellisense had only disappeared in a few classes in one project. It turned out this was because of a missing library on the build path (although it worked previously).
So definitely check all the errors or problems in Eclipse and try to find if a library may be missing
For those who use the latest 3-19 eclipse build:
It just happened to me when upgrading from Oxygen to 3-19 eclipse version, so I assume the auto-complete feature does not migrated correctly during the upgrade process.
The only solution that worked for me was to create a new eclipse workspace, and import the project/s to it. It might take a few minutes, but it worth it - comparing to the time spent on other solutions...
I ran into this and it ended up being I was opening the file with the text editor and not the java editor.
For me the issue was a conflict between several versions of the same library. The Eclipse assist was using an older version than maven.
I had to go to the .m2 directory and delete the unwanted lib version + restart eclipse.
I experience problems on Eclipse Neon when editing a file which does not belong to the project directory. When I copy the same file to the project root directory, not even to the src directory, the completion starts working.
When the file is opened from a different directory, only completion for JRE works. That is for example: java. completes, but junit. does not.
Just in case anyone got to a desperate point where nothing works... It happened to us that the content assist somehow shrunk so no suggestion was shown, just the "Press Ctrl+Space for non-Java..." could be seen.
So, it was just a matter of dragging the corner of the content assist to enlarge the pop-up.
I know, embarrassing. Hope it helps.
Note: this was an Ubuntu server with Xfce4 using Eclipse Oxygen.
If you're experiencing this in an enum, or when initializing an array with anonymous classes, it's a known bug in Eclipse. See Eclipse content assist not working in enum constant parameter list.
We can change the settings as per our requirement.
Suppose we want to make java proposal as highest priority we need to do changes as shown below.
Windows > Preferences > Java > Editor > Content Assist > Advanced
Choose Java proposal and click on up button
For me in Sep 2021 it was an odd Eclipse bug. I had a multi-line string inside an annotation in my Class. This caused just that particular class to fail when trying to code complete (even though the class compiled just fine).