Get rid of Guava (#555)

* Get rid of Guava

* Fix NPE

* Apply suggestions from review

* Checkstyle

* Add braces to precondition checks

* Forbid space

2 files changed, 3 insertions, 4 deletions

diff --git a/enigma-server/src/main/java/cuchaz/enigma/network/DedicatedEnigmaServer.java b/enigma-server/src/main/java/cuchaz/enigma/network/DedicatedEnigmaServer.java
index f20a9d2..af5e34b 100644
--- a/enigma-server/src/main/java/cuchaz/enigma/network/DedicatedEnigmaServer.java
+++ b/enigma-server/src/main/java/cuchaz/enigma/network/DedicatedEnigmaServer.java
@@ -11,7 +11,6 @@ import java.util.concurrent.Executors;
 import java.util.concurrent.LinkedBlockingDeque;
 import java.util.concurrent.TimeUnit;
 
-import com.google.common.io.MoreFiles;
 import joptsimple.OptionParser;
 import joptsimple.OptionSet;
 import joptsimple.OptionSpec;
@@ -103,7 +102,7 @@ public class DedicatedEnigmaServer extends EnigmaServer {
 
                                 if (Files.isDirectory(mappingsFile)) {
                                         mappingFormat = MappingFormat.ENIGMA_DIRECTORY;
-                                } else if ("zip".equalsIgnoreCase(MoreFiles.getFileExtension(mappingsFile))) {
+                                } else if (mappingsFile.getFileName().toString().toLowerCase().endsWith(".zip")) {
                                         mappingFormat = MappingFormat.ENIGMA_ZIP;
                                 } else {
                                         mappingFormat = MappingFormat.ENIGMA_FILE;
diff --git a/enigma-server/src/main/java/cuchaz/enigma/network/ServerAddress.java b/enigma-server/src/main/java/cuchaz/enigma/network/ServerAddress.java
index a8a1029..09a13cc 100644
--- a/enigma-server/src/main/java/cuchaz/enigma/network/ServerAddress.java
+++ b/enigma-server/src/main/java/cuchaz/enigma/network/ServerAddress.java
@@ -2,7 +2,7 @@ package cuchaz.enigma.network;
 
 import java.util.Objects;
 
-import javax.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
 
 public class ServerAddress {
         public final String address;
@@ -23,7 +23,7 @@ public class ServerAddress {
                         return null;
                 }
 
-                if (address.equals("")) {
+                if (address.isEmpty()) {
                         return null;
                 }