Can't access Eclipse marketplace
Here's the solution,
If you are a constant proxy changer like me for various reasons (university, home , workplace and so on..) you are mostly likely to get this error due to improper configuration of connection settings in the eclipse IDE. all you have to do it play around with the current settings and get it to working state. Here's how,,
1. GO TO
Window-> Preferences -> General -> Network Connection.
2. Change the Settings
Active Provider-> Manual-> and check---> HTTP, HTTPS and SOCKS
If your active provider is already set to Manual, try restoring the default (native)
That's all, restart Eclipse and you are good to go!
Considering this as a general programming problem, some possible causes are:
The service could be temporarily broken
You could have a problem with a firewall. These could be local or they could be implemented by your ISPs.
Your proxy HTTP settings (if you need one) could be incorrect. This Answer explains how to adjust the Eclipse-internal proxy settings ... if that is where the problem lies.
It is possible that your access may be blocked by over-active antivirus software.
The service could have blacklisted some net range and your hosts IP address is "collateral damage".
Try connecting to that URL with a web browser to try to see if it is just Eclipse that is affected ... or a broader problem.
Considering this in the context of the Eclipse Marketplace service, first address any local proxy / firewall / AV issues, if they apply. If that doesn't help, the best thing that you can do is to be patient.
It has been observed that the Eclipse Marketplace service does sometimes go down. It doesn't happen often, and when it does happen the problem does get fixed relatively quickly. (Hours, not days ...)
I can't find a "service status" page or feed or similar for the Eclipse services. (If you know of one, please add it as a comment below.)
There may be an "outage" notice on the Eclipse front page. Check for that.
Try to connect to the service URL (refer to the exception message!) using a web browser and/or from other locations. If you succeed, the real problem may be a networking issue at your end.
If you feel the need to complain about Eclipse's services, please don't do it here!! (It is off topic.)
The solution is to set the proxy to "native" as below
Go to "Window-> Preferences -> General -> Network Connection" and change the Settings "Active Provider-> Native". It worked for me.