I am using company proxy and not able to plugin from marketplace?
If you go to the github page, on the right are releases. If you select the release that you want, at the very bottom of that release's page is a list of zipped updatesites, where you can download it from, ex. https://github.com/groovy/groovy-eclipse/wiki/4.0.0-Release-Notes You can then unzip it and install it manually.
Additionally, if you want Eclipse to work through your proxy, add the following in your eclipse.ini file:
-Dorg.eclipse.ecf.provider.filetransfer.excludeContributors=org.eclipse.ecf.provider.filetransfer.httpclient4
-Dhttp.proxyHost=your_proxyservername.your.org
-Dhttp.proxyPort=your_proxy_port
-Dhttp.proxyUser=your_username
-Dhttp.proxyPassword=your_password
-Dhttps.proxyHost=your_proxyservername.your.org
-Dhttps.proxyPort=your_proxy_port
-Dhttps.proxyUser=your_username
-Dhttps.proxyPassword=your_password
-Dhttp.nonProxyHosts=localhost|127.0.0.1
-Dorg.eclipse.equinox.p2.transport.ecf.retry=5
-Dorg.eclipse.ecf.provider.filetransfer.retrieve.connectTimeout=15000
-Dorg.eclipse.ecf.provider.filetransfer.retrieve.readTimeout=1000
-Dorg.eclipse.ecf.provider.filetransfer.retrieve.retryAttempts=20
-Dorg.eclipse.ecf.provider.filetransfer.retrieve.closeTimeout=1000
-Dorg.eclipse.ecf.provider.filetransfer.browse.connectTimeout=3000
-Dorg.eclipse.ecf.provider.filetransfer.browse.readTimeout=1000