print main class in welcome message. #1719

common/src/main/java/com/taobao/arthas/common/PidUtils.java

@@ -1,6 +1,7 @@
 package com.taobao.arthas.common;
 
 import java.lang.management.ManagementFactory;
+import java.util.Map;
 
 /**
  *
@@ -11,6 +12,8 @@ public class PidUtils {
     private static String PID = "-1";
     private static long pid = -1;
 
+    private static String MAIN_CLASS = "";
+
     static {
         // https://stackoverflow.com/a/7690178
         try {
@@ -24,6 +27,16 @@ public class PidUtils {
         } catch (Throwable e) {
             // ignore
         }
+
+        try {
+            for (final Map.Entry<String, String> entry : System.getenv().entrySet()) {
+                if (entry.getKey().startsWith("JAVA_MAIN_CLASS")) // like JAVA_MAIN_CLASS_13328
+                    MAIN_CLASS = entry.getValue();
+            }
+        } catch (Throwable e) {
+            // ignore
+        }
+
     }
 
     private PidUtils() {
@@ -36,4 +49,8 @@ public class PidUtils {
     public static long currentLongPid() {
         return pid;
     }
+
+    public static String mainClass() {
+        return MAIN_CLASS;
+    }
 }

core/src/main/java/com/taobao/arthas/core/command/model/WelcomeModel.java

@@ -10,6 +10,7 @@ public class WelcomeModel extends ResultModel {
     private String version;
     private String wiki;
     private String tutorials;
+    private String mainClass;
 
     public WelcomeModel() {
     }
@@ -58,4 +59,12 @@ public class WelcomeModel extends ResultModel {
     public void setTutorials(String tutorials) {
         this.tutorials = tutorials;
     }
+
+    public String getMainClass() {
+        return mainClass;
+    }
+
+    public void setMainClass(String mainClass) {
+        this.mainClass = mainClass;
+    }
 }

core/src/main/java/com/taobao/arthas/core/shell/term/impl/http/api/HttpApiHandler.java

@@ -286,6 +286,7 @@ public class HttpApiHandler {
             welcomeModel.setVersion(ArthasBanner.version());
             welcomeModel.setWiki(ArthasBanner.wiki());
             welcomeModel.setTutorials(ArthasBanner.tutorials());
+            welcomeModel.setMainClass(PidUtils.mainClass());
             welcomeModel.setPid(PidUtils.currentPid());
             welcomeModel.setTime(DateUtils.getCurrentDate());
             resultDistributor.appendResult(welcomeModel);

core/src/main/java/com/taobao/arthas/core/util/ArthasBanner.java

@@ -114,6 +114,7 @@ public class ArthasBanner {
                         .row("wiki", wiki())
                         .row("tutorials", tutorials())
                         .row("version", version())
+                        .row("main_class", PidUtils.mainClass())
                         .row("pid", PidUtils.currentPid())
                         .row("time", DateUtils.getCurrentDate());
         for (Entry<String, String> entry : infos.entrySet()) {