1 files changed, 34 insertions, 0 deletions
diff --git a/src/main/java/derms/replica/replica2/Servers.java b/src/main/java/derms/replica/replica2/Servers.java
new file mode 100644
index 0000000..4d24745
--- /dev/null
+++ b/src/main/java/derms/replica/replica2/Servers.java
@@ -0,0 +1,34 @@
+package derms.replica.replica2;
+
+import java.net.InetAddress;
+import java.util.Collection;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+public class Servers {
+	private Map<City, InetAddress> servers = new ConcurrentHashMap<City, InetAddress>();
+
+	/** Returns the address of the server located in the specified city, or null if there is no server in the city. */
+	public InetAddress get(City city) {
+		return servers.get(city);
+	}
+
+	/**
+	 *  Associates the specified server address with the specified city.
+	 * If there was already a server associated with the city, the old value is replaced.
+	 * @param city the city where the server is located
+	 * @param addr the address of the server
+	 * @return the previous server address, or null if there was no server associated with this city.
+	 */
+	public InetAddress put(City city, InetAddress addr) {
+		return servers.put(city, addr);
+	}
+
+	public Collection<InetAddress> all() {
+		return servers.values();
+	}
+
+	public int size() {
+		return servers.size();
+	}
+}