Revize 3094b8b2

Update version of log4j

sources/pom.xml

@@ -59 +59 @@
             <version>3.8.0</version>
         </dependency>
 
-        <!-- https://mvnrepository.com/artifact/log4j/log4j -->
+        <!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core -->
         <dependency>
-            <groupId>log4j</groupId>
-            <artifactId>log4j</artifactId>
-            <version>1.2.17</version>
+            <groupId>org.apache.logging.log4j</groupId>
+            <artifactId>log4j-core</artifactId>
+            <version>2.11.1</version>
         </dependency>
+
         <!-- https://mvnrepository.com/artifact/commons-fileupload/commons-fileupload -->
         <dependency>
             <groupId>commons-fileupload</groupId>

sources/src/main/java/cz/zcu/kiv/offscreen/api/Graph.java

@@ -1 +1 @@
 package cz.zcu.kiv.offscreen.api;
 
-import org.apache.log4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import java.util.*;
 
@@ -22 +23 @@
     private String highlightedVertex; // group-ID, vertex-ID
     private String highlightedEdge;
 
-    private Logger logger = Logger.getLogger(Graph.class);
+    private static final Logger logger = LogManager.getLogger();
 
     public Graph() {
         vertices = new HashSet<>();

sources/src/main/java/cz/zcu/kiv/offscreen/session/SessionManager.java

@@ -1 +1 @@
 package cz.zcu.kiv.offscreen.session;
 
-import org.apache.log4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import javax.servlet.http.*;
 import java.util.Arrays;
@@ -11 +12 @@
  */
 public class SessionManager implements HttpSessionListener {
 
-    private static Logger logger = Logger.getLogger(SessionManager.class);
+    private static final Logger logger = LogManager.getLogger();
 
     /**
      * Get session value.

sources/src/main/java/cz/zcu/kiv/offscreen/storage/FileLoader.java

@@ -3 +3 @@
 import org.apache.commons.fileupload.FileItem;
 import org.apache.commons.fileupload.disk.DiskFileItemFactory;
 import org.apache.commons.fileupload.servlet.ServletFileUpload;
-import org.apache.log4j.Logger;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 
 import javax.servlet.http.HttpServletRequest;
 import java.util.HashMap;
@@ -15 +16 @@
     private static final int MAX_FILE_SIZE = 512000000;
     private static final String ACCEPTED_EXTENSION_FILE = "json";
 
-    private Logger logger = Logger.getLogger(FileLoader.class);
+    private static final Logger logger = LogManager.getLogger();
 
     /**
      * Get multipart data from request which was send and return it as a map where key is field name from form and