Follow the guide to 'create-controller hello' but some errors when Resolving plugin.

Hello everyone,

I am very happy to learn how to developed with grails.
I follow the guide to install the grails, but when i try to make a example described in the guide, some error happened.
:(
grails create-app hello
grails> create-controller hello
| Resolving plugin JAR dependencies
:: problems summary ::
:::: ERRORS
Server access Error: Connection timed out url=http://grails.org/plugins/grails-antlr/tags/RELEASE_2_7_6/antlr-2.7.6.pom
Server access Error: Connection timed out url=http://grails.org/plugins/grails-antlr/tags/RELEASE_2_7_6/grails-antlr-2.7.6.jar
Server access Error: Connection timed out url=http://repo.grails.org/grails/core/antlr/antlr/2.7.6/antlr-2.7.6.pom
Server access Error: Connection timed out url=http://repo.grails.org/grails/core/antlr/antlr/2.7.6/antlr-2.7.6.jar
Server access Error: Connection timed out url=http://repo1.maven.org/maven2/antlr/antlr/2.7.6/antlr-2.7.6.pom
Server access Error: Connection timed out url=http://repo1.maven.org/maven2/antlr/antlr/2.7.6/antlr-2.7.6.jar
| Error Failed to install plugin [hibernate-2.1.1]. Plugin has missing JAR dependencies.
| Resolving plugin JAR dependencies...
| Error Error running script create-controller hello: org.codehaus.groovy.grails.cli.ScriptExitException (Use --stacktrace to see the full trace)

not sure why the error happened, is there any problem with my Grails environment?
:)

Thank you.