diff --git a/HMCL/build.gradle b/HMCL/build.gradle
index f802dd095..6524be474 100755
--- a/HMCL/build.gradle
+++ b/HMCL/build.gradle
@@ -19,17 +19,17 @@ import java.util.jar.JarFile
 import java.util.jar.Pack200
 import java.util.zip.GZIPOutputStream
 import java.security.MessageDigest
+import java.util.jar.JarOutputStream
+import java.util.zip.ZipEntry
+import java.util.zip.ZipFile
 
 plugins {
     id "edu.sc.seis.macAppBundle" version "2.1.6"
     id "me.tatarka.retrolambda" version "3.5.0"
     id 'edu.sc.seis.launch4j' version '2.3.0'
+    id "org.jetbrains.kotlin.jvm" version "1.1.2-2"
 }
 
-import java.util.jar.JarOutputStream
-import java.util.zip.ZipEntry
-import java.util.zip.ZipFile
-
 if (!hasProperty('mainClass')) {
     ext.mainClass = 'org.jackhuang.hmcl.Main'
 }
diff --git a/HMCLAPI/build.gradle b/HMCLAPI/build.gradle
index 08dbc7cb1..0bb8722bb 100644
--- a/HMCLAPI/build.gradle
+++ b/HMCLAPI/build.gradle
@@ -18,6 +18,7 @@
 
 plugins {
     id "me.tatarka.retrolambda" version "3.5.0"
+    id "org.jetbrains.kotlin.jvm" version "1.1.2-2"
 }
 
 if (System.getenv("BUILD_NUMBER") != null)
diff --git a/HMCLCore/build.gradle b/HMCLCore/build.gradle
index 4074a1589..3f0ed1261 100644
--- a/HMCLCore/build.gradle
+++ b/HMCLCore/build.gradle
@@ -18,6 +18,7 @@
 
 plugins {
     id "me.tatarka.retrolambda" version "3.5.0"
+    id "org.jetbrains.kotlin.jvm" version "1.1.2-2"
 }
 
 if (System.getenv("BUILD_NUMBER") != null)
diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/util/log/Level.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/util/log/Level.java
index 4a7a985e8..ebec9b1d6 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/util/log/Level.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/util/log/Level.java
@@ -47,7 +47,7 @@ public enum Level {
         return this.level <= level.level;
     }
 
-    public static final Pattern MINECRAFT_LOGGER = Pattern.compile("\\[(?<timestamp>[0-9:]+)\\] \\[[^/]+/(?<level>[^\\]]+)\\]");
+    public static final Pattern MINECRAFT_LOGGER = Pattern.compile("\\[(?<timestamp>[0-9:]+)\\] \\[[^/]+/(?<level>[^\\]]+)\\] \\[(?<category>[^\\]]+)\\]");
     public static final String JAVA_SYMBOL = "([a-zA-Z_$][a-zA-Z\\d_$]*\\.)+[a-zA-Z_$][a-zA-Z\\d_$]*";
 
     public static Level guessLevel(String line, Level preLevel) {
@@ -58,26 +58,36 @@ public enum Level {
             String levelStr = m.group("level");
             if (null != levelStr)
                 switch (levelStr) {
-                case "INFO":
-                    level = INFO;
-                    break;
-                case "WARN":
-                    level = WARN;
-                    break;
-                case "ERROR":
-                    level = ERROR;
-                    break;
-                case "FATAL":
-                    level = FATAL;
-                    break;
-                case "TRACE":
-                    level = TRACE;
-                    break;
-                case "DEBUG":
-                    level = DEBUG;
-                    break;
-                default:
-                    break;
+                    case "INFO":
+                        level = INFO;
+                        break;
+                    case "WARN":
+                        level = WARN;
+                        break;
+                    case "ERROR":
+                        level = ERROR;
+                        break;
+                    case "FATAL":
+                        level = FATAL;
+                        break;
+                    case "TRACE":
+                        level = TRACE;
+                        break;
+                    case "DEBUG":
+                        level = DEBUG;
+                        break;
+                    default:
+                        break;
+                }
+            String level2Str = m.group("category");
+            if (null != level2Str)
+                switch(level2Str) {
+                    case "STDOUT":
+                        level = INFO;
+                        break;
+                    case "STDERR":
+                        level = ERROR;
+                        break;
                 }
         } else {
             if (line.contains("[INFO]") || line.contains("[CONFIG]") || line.contains("[FINE]")
@@ -94,10 +104,10 @@ public enum Level {
             return FATAL;
 
         if (line.contains("Exception in thread")
-            || line.matches("\\s+at " + JAVA_SYMBOL)
-            || line.matches("Caused by: " + JAVA_SYMBOL)
-            || line.matches("([a-zA-Z_$][a-zA-Z\\d_$]*\\.)+[a-zA-Z_$]?[a-zA-Z\\d_$]*(Exception|Error|Throwable)")
-            || line.matches("... \\d+ more$"))
+                || line.matches("\\s+at " + JAVA_SYMBOL)
+                || line.matches("Caused by: " + JAVA_SYMBOL)
+                || line.matches("([a-zA-Z_$][a-zA-Z\\d_$]*\\.)+[a-zA-Z_$]?[a-zA-Z\\d_$]*(Exception|Error|Throwable)")
+                || line.matches("... \\d+ more$"))
             return ERROR;
         return preLevel.level < level.level ? preLevel : level;
     }
diff --git a/HMCLaF/build.gradle b/HMCLaF/build.gradle
index ab3062c7a..a7a27dc46 100755
--- a/HMCLaF/build.gradle
+++ b/HMCLaF/build.gradle
@@ -18,6 +18,7 @@
 
 plugins {
     id "me.tatarka.retrolambda" version "3.5.0"
+    id "org.jetbrains.kotlin.jvm" version "1.1.2-2"
 }
 
 if (System.getenv("BUILD_NUMBER") != null)
diff --git a/common.gradle b/common.gradle
index f8da1faa2..4259068b5 100755
--- a/common.gradle
+++ b/common.gradle
@@ -27,6 +27,7 @@ apply plugin: 'maven'
 
 dependencies {
     compile 'com.google.code.gson:gson:2.2.4' // Apache License 2.0
+    compile "org.jetbrains.kotlin:kotlin-stdlib:1.1.2"
 }
 
 task sourcesJar(type: Jar, dependsOn: classes, description: 'Creates a jar from the source files.') {