Smaller fixes

Author: cstamas

src/main/java/io/fabric8/maven/docker/AbstractDockerMojo.java

@@ -2,10 +2,10 @@
 
 import java.io.File;
 import java.io.IOException;
-import java.util.Date;
+import java.util.ArrayList;
 import java.util.Collections;
+import java.util.Date;
 import java.util.List;
-import java.util.ArrayList;
 import java.util.Map;
 import java.util.Properties;
 import java.util.regex.Matcher;

src/main/java/io/fabric8/maven/docker/StopMojo.java

@@ -98,11 +98,6 @@ public void execute() throws MojoExecutionException, MojoFailureException {
                 // HttpDelete class is not used during start mojo, so we need to load it and initialize it. It is not
                 // possible to load classes in the shutdown hook as
                 Class.forName("org.apache.http.client.methods.HttpDelete", true, this.getClass().getClassLoader());
-
-                // com.google.common.base.Strings class from com.google.guava is required and it depends on Platforms
-                // Used in @see io.fabric8.maven.docker.util.ImageNameFormatter
-                Class.forName("com.google.common.base.Strings", true, this.getClass().getClassLoader());
-                Class.forName("com.google.common.base.Platform", true, this.getClass().getClassLoader());
             } catch (ClassNotFoundException e) {
                 log.error("Failure in loading org.apache.http.client.methods.HttpDelete class: %s", e.getMessage());
             }

src/main/java/io/fabric8/maven/docker/assembly/DockerFileBuilder.java

@@ -2,11 +2,13 @@
 
 import java.io.File;
 import java.io.IOException;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import com.google.common.base.Joiner;
 import io.fabric8.maven.docker.config.Arguments;
 import io.fabric8.maven.docker.config.HealthCheckConfiguration;
 
@@ -21,8 +23,6 @@
  */
 public class DockerFileBuilder {
 
-    private static final Joiner JOIN_ON_COMMA = Joiner.on("\",\"");
-
     private static final Pattern ENV_VAR_PATTERN = Pattern.compile("^\\$(\\{[a-zA-Z0-9_]+\\}|[a-zA-Z0-9_]+).*");
 
     // Base image to use as from
@@ -177,13 +177,13 @@ private static void buildArguments(StringBuilder b, DockerFileKeyword key, boole
         if (arguments.getShell() != null) {
             arg = arguments.getShell();
         } else {
-            arg = "[\""  + JOIN_ON_COMMA.join(arguments.getExec()) + "\"]";
+            arg = "[\""  + String.join("\",\"", arguments.getExec()) + "\"]";
         }
         key.addTo(b, newline, arg);
     }
 
     private static void buildArgumentsAsJsonFormat(StringBuilder b, DockerFileKeyword key, boolean newline, Arguments arguments) {
-        String arg = "[\""  + JOIN_ON_COMMA.join(arguments.asStrings()) + "\"]";
+        String arg = "[\""  + String.join("\",\"", arguments.asStrings()) + "\"]";
         key.addTo(b, newline, arg);
     }
 

src/main/java/io/fabric8/maven/docker/util/AuthConfigFactory.java

@@ -68,7 +68,7 @@ public class AuthConfigFactory {
             "docker.io", "index.docker.io", "registry.hub.docker.com"
     };
 
-    private SettingsDecrypter settingsDecrypter;
+    private final SettingsDecrypter settingsDecrypter;
 
     /**
      * Constructor which should be used during startup phase of a plugin

src/main/java/io/fabric8/maven/docker/util/CredentialHelperClient.java

@@ -118,10 +118,9 @@ public JsonObject getCredentialNode(String registryToLookup) throws IOException
                     throw ex;
                 }
             }
-            String joinedReply = String.join("\n", reply);
-            JsonObject credentials = JsonFactory.newJsonObject(joinedReply);
+            JsonObject credentials = JsonFactory.newJsonObject(String.join("\n", reply));
             if (!credentials.has(SECRET_KEY) || !credentials.has(USERNAME_KEY)) {
-                return null;  // If keys are missing, return null
+                return null;
             }
             return credentials;
         }

src/main/java/io/fabric8/maven/docker/util/ImageNameFormatter.java

@@ -180,7 +180,7 @@ public String doTransform(String tag, Date now) {
 
             public String transform(MavenProject project, String tag, Date now) {
                 // In case the Maven property is also a placeholder, replace it as well
-                if(isEmpty(tag) || tag.equals("%" + letter)) {
+                if ((tag == null || tag.trim().isEmpty()) || tag.equals("%" + letter)) {
                     tag = project.getVersion();
                 }
                 return doTransform(tag, now);