I'm using Eclipse Eclipse IDE for Java Developers [Version: 2018-12 (4.10.0)
Build id: 20181214-0600] to develop a JavaFX project but I got some problems.
After a Java update, I've found several errors in my CSS files. Eclipse seems to think the CSS files are Java source code, as figured in the image below.
When I drag the mouse on a error, the description is "Syntax error on token 'Invalid character', interface expected" (because of # symbol)
I'm sure the code is correct because there are no errors before the latest java update to version 1.8.2.
Anyone can help me?
Most likely what happened here is what #Gianpio Benincasa said: You've created a new class, then in the file explorer you renamed it.
However, it's worth checking this one: Go to window/preferences, type 'associations' in the filter box to quickly nav to setting General>Editors>File Associations, and scroll through the file types list for *.css. Click on it, and check which editors are associated with it.
An eclipse with no particularly relevant plugins should only list 'Text Editor', and it should be marked as default. If you added plugins specifically for editing CSS, those will also be listed (and one of those is now probably default instead). Perhaps you or someone else went out of their way to add the java editor to this list somehow. If that is the case, simply make 'text editor' the default again (click it, click 'default'), then click on the java editor, and click 'remove'.
for eclipse that is a java class, in fact the icon has the "J". Probably when you created it you have created a new class and then have renamed it.
Create a new generic file instead a java class and copy the contents to the new file.
For create a generic file, rightclick and follow new-> other-> General-> files
Have a nice day
Is there a way to look into originally given methods by API?
I am a beginner in programming and sometimes feel like taking huge shortcuts when using given methods and not really having an idea what tools i would use if i had to write it on my own.
Thanks in advance for given advices.
You want to look into Java code?
Here is a snapshot to attach java documentation and source code
Click Windows
Click Preferences
Click Java
Click Installed JRE
See the image for more steps
After you clarified your question, I think I can suggest you a solution. Let's suppose that you want to see what java.util.Collections.reverse(List list) do! When you downloaded the JDK you downloaded the sources too. You can find it here (or else to where you placed) for example for JDK8: C:\Program Files\Java\jdk1.8.0_66 => src.zip In this zip file you can find \java\util directories and inside this you can find Collections.java and inside this you can find the reverse(List list) method in JAVA source format. (Anyway, you can find the bytecode of this example method too in the rt.jar...but I think you shouldn't bother yourself with it if you are a beginner.) I hope I could help.
First time post, long time watcher. Can't wait for my classmates to read this (they use the site too)
I am using Eclipse Juno w/ Java SE 1.7
I am having an eclipse problem. It doesn't happen all the time, typically only during File IO. I'm using my debugger perspective in Eclipse to try and trouble shoot some problems (its really a simple program).
UPDATE: Apparently new users are not allowed to upload screen shots. If you could take the time to click on the link to witness my problem I would appreciate it.
Screen Shot Link (not java code):
imgur.com/5IxI3.png
As you can see I am getting an odd thread.class problem. I have even reinstalled java. Could it be something with my code as well then?
Thanks for anyone who offers input or helps in anyway. I do have about a week before this is do so I'm not just looking for free answers, just frustrated. Thanks!
If I understand your question correctly, you need to attach source because Thread is API class.
Download Java source (not binary exe file) from Oracle
Go to eclipse Yourproject --> Properties --> Java Build Path >
Libraries and expand JRE System Library --> jre version--> rt.jar.
Select Source attachment ---> Point to the down loaded source.
Read this tutorial for more info.
Up to a few days ago, Eclipse was working fine in locating the javadoc for base classes such as Java.io.File. Recently, though, hovering over these classes only yields a message indicating that the source and javadoc are missing:
"Note: This element has no attached source and the Javadoc could not be found in the attached Javadoc."
I couldn't for the life of me locate the option that would let me reselect the location of the basic documentation. Does anyone know how to fix this?
I encountered this problem now a couple of times too. It's especially annoying if you have a lot of projects in your workspace and you don't want to set the javadoc locations for each project.
Referencing the online documentation works well indeed, and there is a way to do that globally for all Java libraries:
Go to: Window -> Preferences
Expand: Java -> Installed JREs
Select your default Java installation
Press ''Edit''
Select all the JRE system libraries
Press ''Javadoc Location...''
In the Javadoc location path put in the path to the online documentation. For Java 8 for example this is http://docs.oracle.com/javase/8/docs/api/. (If you press ''Validate...'' it will tell you if it is a valid javadoc location.)
Press ''OK'', then ''Finish'', then ''OK''
And here you have some images:
And your basic Java javadoc is ready to go.
Expand your JRE System library and find rt.jar (classes.jar for Mac OS X). Right click, and select 'Properties'.
You can then specify the Javadoc location (as well as the source location).
The best way to do it is
Go to Project > Properties > Java Build Path > Libraries and expand JRE System Library [your jre version] then, rt.jar. Select Source attachment, click Edit…. Select the source code file (External File…) and press OK.
Other ways to attach java source code is mentioned in this link
http://www.cavdar.net/2008/07/14/3-ways-of-jdk-source-code-attachment-in-eclipse/
Press ctrl+click (or command+click if you're on a Mac) on any method which doesn't have javadocs. For example, in this line:
System.out.println();
... assuming that no javadocs are available for println, control-clicking on println will open a new tab with a button labeled "Attach Source...". And that's it!
I had the same problem.
I uninstalled eclipse, removed all eclipse specific data from my user's home- and application data directory, uninstalled all Java JREs and JDKs but nothing helped.
The solution on my system was to change the protocol in the JavaDoc URL from HTTP to HTTPS
e.g. for JRE 7 i changed the URL from http://docs.oracle.com/javase/7/docs/api/ to https://docs.oracle.com/javase/7/docs/api/
(use the steps mentioned by Terry and replace the 'http' with 'https')
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).