SE450: Using Eclipse: Installation problems? [7/10]

If you have errors after installing eclipse and the code from class, please watch this: Eclipse problems

Uninstall everything and try again.

If that does not work, email me ASAP. Don't waste time trying to fix a broken eclipse install.

• describe the problem. More detail than eclipse is messed up.
• including a screenshot of eclipse showing the problem

Here is some advice that has worked in the past.

It has happened for some students that suddenly eclipse shows a bunch of
errors, whereas previously everything was fine.

First thing to try is to clean all projects using

Project -> Clean

Then look at the previous slide to see if it matches your situation.
You maybe can adjust the compiler settings to get it to work.

If you still have problems, you should just start with a fresh workspace.

Exit eclipse.

Using the finder, go to your workspace.
Rename it to oldworkspace and create a new folder called "workspace"
Inside workspace, create a new folder called "se450"
Move the following folders from oldworkspace/se450 to workspace/se450

lib
data
src

Now start eclipse in the new "workspace".
It should be as though you are starting eclipse for the first time.
Follow the instructions provided earlier to add the "se450" project
and to turn off the warnings for unused variables and private fields.

Some more advice that has worked in the past.

It may happen that eclipse shows compiler errors in the code that I have provided.
For example, it may say something like:

-- The method printf(String, Object[]) in the type PrintWriter is not
   applicable for the arguments (String, int, long)
-- The method put(ThreadReference, Stack<HashMap<LocalVariable,Value>>) in
   the type HashMap<ThreadReference,Stack<HashMap<LocalVariable,Value>>> is
   not applicable for the arguments (ThreadReference, Stack<Object>)

These are compiler issues, indicating that you are not using the correct
language compliance level.
To fix this, do the following:


Check that Project Specific Settings are NOT checked in the following places

Project -> Properties -> Java build path
Project -> Properties -> Java compiler

Then check 

Preferences -> Java -> Compiler
Preferences -> Java -> Installed JREs

to make sure that compliance level is set to 1.8 
and that a Java SE 8 runtime is checked.

Then got to 

Project -> Clean

and clean all projects.