[main] StringFormatter: support formatting throwables

src/main/java/io/gitlab/jfronny/commons/StringFormatter.java

@@ -1,5 +1,6 @@
 package io.gitlab.jfronny.commons;
 
+import java.io.*;
 import java.util.*;
 
 public class StringFormatter {
@@ -10,6 +11,21 @@ public class StringFormatter {
                 return String.format(Locale.US, "%s", d);
             else
                 return String.format(Locale.US, "%.0f", d);
+        } else if (o instanceof Throwable t) {
+            try {
+                return t.getMessage() + getStackTrace(t);
+            } catch (IOException e) {
+                return t.toString();
+            }
         } else return o.toString();
     }
+
+    public static String getStackTrace(Throwable t) throws IOException {
+        try (ByteArrayOutputStream baot = new ByteArrayOutputStream()) {
+            try (PrintStream ps = new PrintStream(baot, true)) {
+                t.printStackTrace(ps);
+            }
+            return baot.toString();
+        }
+    }
 }

src/main/java/io/gitlab/jfronny/commons/log/Logger.java

@@ -100,17 +100,6 @@ public interface Logger {
 
     default String format(String msg, Throwable t) {
         if (t == null) return msg;
-        return msg + System.lineSeparator() + format(t);
-    }
-
-    default String format(Throwable t) {
-        try (ByteArrayOutputStream baot = new ByteArrayOutputStream()) {
-            try (PrintStream ps = new PrintStream(baot, true)) {
-                t.printStackTrace(ps);
-            }
-            return baot.toString();
-        } catch (IOException e) {
-            return t.toString();
-        }
+        return msg + System.lineSeparator() + StringFormatter.toString(t);
     }
 }