Google Cloud Endpoints : Not able to open http://localhost:8080/_ah/api/explorer behind a proxy network

[saurabh via StackOverflow]

When i am opening http://localhost:8080/_ah/api/explorer Eclipse is showing an error- >

com.google.apphosting.utils.jetty.JettyLogger warn
[INFO] WARNING: /_ah/api/static/proxy.html: java.io.IOException: Could not fetch URL: https://webapis-discovery.appspot.com/_ah/api/static/proxy.html, error: Received exception executing http method GET against URL https://webapis-discovery.appspot.com/_ah/api/static/proxy.html: Connection to https://webapis-discovery.appspot.com refused

Few lines above Eclipse shows an SEVERE error- >

[INFO] SEVERE: javax.servlet.ServletContext log: unavailable
[INFO] java.io.IOException: Could not fetch URL: https://webapis-discovery.appspot.com/_ah/api/static/proxy.html, error: Received exception executing http method GET against URL https://webapis-discovery.appspot.com/_ah/api/static/proxy.html: Connection to https://webapis-discovery.appspot.com refused
[INFO]  at com.google.appengine.api.urlfetch.URLFetchServiceImpl.convertApplicationException(URLFetchServiceImpl.java:138)
[INFO]  at com.google.appengine.api.urlfetch.URLFetchServiceImpl.fetch(URLFetchServiceImpl.java:45)
[INFO]  at com.google.apphosting.utils.security.urlfetch.URLFetchServiceStreamHandler$Connection.fetchResponse(URLFetchServiceStreamHandler.java:417)
[INFO]  at com.google.apphosting.utils.security.urlfetch.URLFetchServiceStreamHandler$Connection.getInputStream(URLFetchServiceStreamHandler.java:296)
[INFO]  at com.google.apphosting.utils.security.urlfetch.URLFetchServiceStreamHandler$Connection.getResponseCode(URLFetchServiceStreamHandler.java:149)
[INFO]  at com.google.appengine.repackaged.com.google.api.client.http.javanet.NetHttpResponse.<init>(NetHttpResponse.java:36)
[INFO]  at com.google.appengine.repackaged.com.google.api.client.http.javanet.NetHttpRequest.execute(NetHttpRequest.java:94)
[INFO]  at com.google.appengine.repackaged.com.google.api.client.http.HttpRequest.execute(HttpRequest.java:965)
[INFO]  at com.google.api.server.spi.tools.devserver.StaticServlet.getStaticContent(StaticServlet.java:58)
[INFO]  at com.google.api.server.spi.tools.devserver.StaticServlet.cacheContent(StaticServlet.java:50)
[INFO]  at com.google.api.server.spi.tools.devserver.StaticServlet.init(StaticServlet.java:43)
[INFO]  at javax.servlet.GenericServlet.init(GenericServlet.java:212)
[INFO]  at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:440)
[INFO]  at org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:339)
[INFO]  at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
[INFO]  at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
[INFO]  at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
[INFO]  at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
[INFO]  at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:127)
[INFO]  at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
[INFO]  at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
[INFO]  at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
[INFO]  at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63)
[INFO]  at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
[INFO]  at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
[INFO]  at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
[INFO]  at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
[INFO]  at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
[INFO]  at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectRequest(DevAppServerModulesFilter.java:366)
[INFO]  at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectModuleRequest(DevAppServerModulesFilter.java:349)
[INFO]  at com.google.appengine.tools.development.DevAppServerModulesFilter.doFilter(DevAppServerModulesFilter.java:116)
[INFO]  at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
[INFO]  at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
[INFO]  at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
[INFO]  at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
[INFO]  at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
[INFO]  at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
[INFO]  at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:98)
[INFO]  at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
[INFO]  at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:491)
[INFO]  at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
[INFO]  at org.mortbay.jetty.Server.handle(Server.java:326)
[INFO]  at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
[INFO]  at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
[INFO]  at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547)
[INFO]  at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
[INFO]  at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
[INFO]  at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
[INFO]  at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

My college has a proxy server, i have already changed the system wide proxy settings and eclipse proxy settings in Window->Preferences->General->Network Connections . Everything else in Ubuntu works fine except this. Internet is working inside Eclipse too.

Screenshot showing eclipse Network settings -

http://i1282.photobucket.com/albums/a540/saurabh595/Screenshotfrom2014-08-16_zps35144efe.png

When i try using my mobile internet connection(without proxy server) it works sometimes and shows same error otherwise.

I've been trying to solve this by doing many Google Searches and trying many things out, but I just cannot seem to be able to proceed any further. I would very much appreciate any help I can get from this community of professionals.

Thanks

Please DO NOT REPLY directly to this email but go to StackOverflow:
http://stackoverflow.com/questions/25338650/google-cloud-endpoints-not-able-to-open-http-localhost8080-ah-api-explorer