Exception in thread "main" java.net.UnknownHostException

Why am i getting this error when i try to connect to my Zookeeper after starting the docker-compose...
And i can't connect to my labs_control-center_1 using localhost:9021

Connecting to zookeeper:2181
Exception in thread "main" java.net.UnknownHostException: zookeeper: Name or service not known
at java.base/java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
at java.base/java.net.InetAddress$PlatformNameService.lookupAllHostAddr(InetAddress.java:929)
at java.base/java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1519)
at java.base/java.net.InetAddress$NameServiceAddresses.get(InetAddress.java:848)
at java.base/java.net.InetAddress.getAllByName0(InetAddress.java:1509)
at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1368)
at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1302)
at org.apache.zookeeper.client.StaticHostProvider.(StaticHostProvider.java:61)
at org.apache.zookeeper.ZooKeeper.(ZooKeeper.java:445)
at org.apache.zookeeper.ZooKeeperMain.connectToZK(ZooKeeperMain.java:281)
at org.apache.zookeeper.ZooKeeperMain.(ZooKeeperMain.java:296)
at org.apache.zookeeper.ZooKeeperMain.main(ZooKeeperMain.java:289)