java.lang.NoClassDefFoundError: org/eclipse/core/resources/ResourcesPlugin

java.lang.NoClassDefFoundError: org/eclipse/core/resources/ResourcesPlugin

if you create a Debug configuration from your product file, in my case CDOServer.product, then

1. you go an select the Plug-ins tab in the Debug Configuration

2. then click "Add Required plug-ins"

it may build a dependency that just does not work.

It seems you have do step 1 above, then

2. "Deselect All"

3. Select your own package

4. Click "Add Required plug-ins" a few times until the number of required plugins stop increasing, see the display "x out of y selected"

ref : Eclipse

Java was started but returned exit code = 1

“Java was started but returned exit code = 1”

go to the eclipse dir and edit eclipse.ini

just before -vmargs paste the following path of the jvm

ex :

...

-vm

C:\path to installed direc \Java\jre1.8.0_40\bin\server\jvm.dll

-vmargs

Several ports (8005, 8080, 8009) required by Tomcat Server at localhost are already in use

Several ports (8005, 8080, 8009) required by Tomcat Server at localhost are already in use

do : netstat -a -o -n

kill process id : taskkill /F /PID 6532

ref : stackoverflow

src/main/java not visible in project folder eclipse

src/main/java not visible in project folder eclipse

steps :
1) right click on project.
2) click on build path.
3) select configure buildpath.
4) select order and export
5) click and select.
a) jre system lib.
b) maven dependency 

Eclipse shortcuts

Eclipse shortcuts

Navigational Shortcuts:

F10

Main menu:

Shift+ F10 Context menu
Ctrl +F10 View menu

Workspace navigation:

F12 Activate editor

Ctrl+Shift+W Switch editor
Ctrl +F6 Next editor
Ctrl +Shift+ F6 Prev editor
Ctrl F7 Next workspace
Ctrl Shift F7 Prev workspace
Ctrl+ F8 Next perspective
Ctrl +Shift+ F8 Prev perspective
Alt +Left Back
Alt+ Right Forward

Files:

Alt +Shift+ S Show in…
Ctrl+ Shift+ R Jump to file
Ctrl+ N New file
Ctrl +S Save file
Ctrl +Shift+ S Save all files
Ctrl+ F4 Close file
Ctrl+ Shift+ F4 Close all files

Find:

Ctrl +L Goto line
Ctrl +F Find
Ctrl +J Incremental find
Ctrl +Shift+ J Incremental find prev
Ctrl+ K Find next
Ctrl +Shift+ K Find prev
Ctrl +H Search workspace
Ctrl +(dot) Navigate next
Ctrl +(comma) Navigate prev

Java navigation:

F3 Goto declaration
Ctrl+ Shift+ U Find references in file
Ctrl +Shift+ G Find references in workspace
Ctrl+ G Find declarations in workspace
Ctrl +Shift+ P Navigate to matching bracket/brace
Ctrl +T Popup type hierarchy
Ctrl +Shift+ T Open Type
Ctrl +O Outline of current source
Ctrl +F3 Outline of current cursor position
Ctrl +Shift+ Arrow Jump beetween methods up or down
F2 Show Javadoc
F4 Show hierarchy
Ctrl +Alt+ H Open call hierarchy

General editing:

Alt+ Arrow+ Move line(s) up or down
Alt +Shift+ Up Expand selection to enclosing element
Alt +Shift+ Right Expand selection to next element
Alt+ Shift+ Left Expand selection to previous element
Alt +Shift+ Down Restore previous selection
Ctrl +Alt +Arrow Duplicate line(s) up or down
Shift +Enter Insert line below
Ctrl +Shift+ Enter Insert line above
Ctrl +D Delete line
Ctrl +Shift+ Q Toggle Quick Diff
Ctrl +Shift+ Y Convert to lowercase
Ctrl +Shift +X Convert to uppercase

Java editing:

Al+t Shift+ U Remove occurrence annotations
Ctrl +1 Quick fix (works even when there are no errors
Ctrl +Shift+ M Add import
Ctrl +Shift+ F Reformat
Ctrl +Shift+ O Organize Imports
Ctrl +/ Comment
Ctrl +\ UnComment
Ctrl +Shift+ Space Parameter hints
Ctrl Hyperlink identifier
Ctrl+ I Correct indentation
Shift+ Space Incremental content assist

Debugger:

F5 Step into
F6 Step over
F7 Run to return
F8 Resume
F9 Relaunch last
F11 Run/debug last
Ctrl+ F11 Run
Ctrl +Shift+ B Toggle breakpoint
Ctrl+ D Display
Ctrl +Q Inspect
Ctrl +R Run to line
Ctrl +U Run snippet

Refactoring:

Alt+ T Refactoring menu
Ctrl+ Shift+ Z Undo refactor
Ctrl +Shift+ Y Redo refactor
Alt +Shift +R Rename
Alt +Shift+ V Move
Alt +Shift+ I Inline
Alt +Shift+ M Extract method
Alt +Shift+ L Extract local
Alt +Shift+ C Change method signature

Misc:

F5 Refresh
F1 Infopop
F2 Show resizeable hover

Thanks to Sathya

org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]]A child container failed during start

solution : clean the tomcat server on eclipse and restart the server.

Java was started but returned exit code=13. while starting the eclipse.

This is happen because of you might have updated addon/plugin and might have installed a older version of java which will set path to the older version.

So here are the solution what i have tried.

1.uninstall the older version of  java.
2. set the latest java path to the environment variable.
3. Restart the eclipse.