Rails server failed

I encountered a problem while trying to start my rails server and still can't find a answer.

➜ test_app git:(master) ✗ rails server => Booting Puma => Rails 5.0.0 application starting in development on http://localhost:3000 => Runrails server -h` for more startup options Puma starting in single mode...

• Version 3.6.0 (ruby 2.3.0-p0), codename: Sleepy Sunday Serenity
• Min threads: 5, max threads: 5
• Environment: development
• Listening on tcp://localhost:3000 Exiting /usr/local/lib/ruby/gems/2.3.0/gems/puma-3.6.0/lib/puma/binder.rb:266:in initialize': Address already in use - bind(2) for "::1" port 3000 (Errno::EADDRINUSE) from /usr/local/lib/ruby/gems/2.3.0/gems/puma-3.6.0/lib/puma/binder.rb:266:innew' from /usr/local/lib/ruby/gems/2.3.0/gems/puma-3.6.0/lib/puma/binder.rb:266:in add_tcp_listener' from /usr/local/lib/ruby/gems/2.3.0/gems/puma-3.6.0/lib/puma/binder.rb:260:inblock in add_tcp_listener' from /usr/local/lib/ruby/gems/2.3.0/gems/puma-3.6.0/lib/puma/binder.rb:259:in each' from /usr/local/lib/ruby/gems/2.3.0/gems/puma-3.6.0/lib/puma/binder.rb:259:inadd_tcp_listener' from /usr/local/lib/ruby/gems/2.3.0/gems/puma-3.6.0/lib/puma/binder.rb:102:in block in parse' from /usr/local/lib/ruby/gems/2.3.0/gems/puma-3.6.0/lib/puma/binder.rb:85:ineach' from /usr/local/lib/ruby/gems/2.3.0/gems/puma-3.6.0/lib/puma/binder.rb:85:in parse' from /usr/local/lib/ruby/gems/2.3.0/gems/puma-3.6.0/lib/puma/runner.rb:133:inload_and_bind' from /usr/local/lib/ruby/gems/2.3.0/gems/puma-3.6.0/lib/puma/single.rb:85:in run' from /usr/local/lib/ruby/gems/2.3.0/gems/puma-3.6.0/lib/puma/launcher.rb:172:inrun' from /usr/local/lib/ruby/gems/2.3.0/gems/puma-3.6.0/lib/rack/handler/puma.rb:51:in run' from /usr/local/lib/ruby/gems/2.3.0/gems/rack-2.0.1/lib/rack/server.rb:296:instart' from /usr/local/lib/ruby/gems/2.3.0/gems/railties-5.0.0/lib/rails/commands/server.rb:79:in start' from /usr/local/lib/ruby/gems/2.3.0/gems/railties-5.0.0/lib/rails/commands/commands_tasks.rb:90:inblock in server' from /usr/local/lib/ruby/gems/2.3.0/gems/railties-5.0.0/lib/rails/commands/commands_tasks.rb:85:in tap' from /usr/local/lib/ruby/gems/2.3.0/gems/railties-5.0.0/lib/rails/commands/commands_tasks.rb:85:inserver' from /usr/local/lib/ruby/gems/2.3.0/gems/railties-5.0.0/lib/rails/commands/commands_tasks.rb:49:in run_command!' from /usr/local/lib/ruby/gems/2.3.0/gems/railties-5.0.0/lib/rails/commands.rb:18:in<top (required)>' from /Users/jay/RailsProjects/test_app/bin/rails:9:in require' from /Users/jay/RailsProjects/test_app/bin/rails:9:in<top (required)>' from /usr/local/lib/ruby/gems/2.3.0/gems/spring-1.7.2/lib/spring/client/rails.rb:28:in load' from /usr/local/lib/ruby/gems/2.3.0/gems/spring-1.7.2/lib/spring/client/rails.rb:28:incall' from /usr/local/lib/ruby/gems/2.3.0/gems/spring-1.7.2/lib/spring/client/command.rb:7:in call' from /usr/local/lib/ruby/gems/2.3.0/gems/spring-1.7.2/lib/spring/client.rb:30:inrun' from /usr/local/lib/ruby/gems/2.3.0/gems/spring-1.7.2/bin/spring:49:in <top (required)>' from /usr/local/lib/ruby/gems/2.3.0/gems/spring-1.7.2/lib/spring/binstub.rb:11:inload' from /usr/local/lib/ruby/gems/2.3.0/gems/spring-1.7.2/lib/spring/binstub.rb:11:in <top (required)>' from /usr/local/lib/ruby/site_ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:inrequire' from /usr/local/lib/ruby/site_ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in require' from /Users/jay/RailsProjects/test_app/bin/spring:13:in<top (required)>' from bin/rails:3:in load' from bin/rails:3:in<main>' `