improve banner, support app_name, start_time. #2990

Author: hengyunabc

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

@@ -112,13 +112,25 @@ public static String welcome() {
 
     public static String welcome(Map<String, String> infos) {
         logger.info("Current arthas version: {}, recommend latest version: {}", version(), latestVersion());
+        String appName = System.getProperty("project.name");
+        if (appName == null) {
+            appName = System.getProperty("app.name");
+        }
+        if (appName == null) {
+            appName = System.getProperty("spring.application.name");
+        }
         TableElement table = new TableElement().rightCellPadding(1)
                         .row("wiki", wiki())
                         .row("tutorials", tutorials())
                         .row("version", version())
-                        .row("main_class", PidUtils.mainClass())
-                        .row("pid", PidUtils.currentPid())
-                        .row("time", DateUtils.getCurrentDateTime());
+                        .row("main_class", PidUtils.mainClass());
+
+        if (appName != null) {
+            table.row("app_name", appName);
+        }
+        table.row("pid", PidUtils.currentPid())
+             .row("start_time", DateUtils.getStartDateTime())
+             .row("currnt_time", DateUtils.getCurrentDateTime());
         for (Entry<String, String> entry : infos.entrySet()) {
             table.row(entry.getKey(), entry.getValue());
         }

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

@@ -1,6 +1,10 @@
 package com.taobao.arthas.core.util;
 
+import java.lang.management.ManagementFactory;
+import java.lang.management.RuntimeMXBean;
+import java.time.Instant;
 import java.time.LocalDateTime;
+import java.time.ZoneId;
 import java.time.format.DateTimeFormatter;
 
 /**
@@ -21,4 +25,16 @@ public static String getCurrentDateTime() {
     public static String formatDateTime(LocalDateTime dateTime) {
         return DATE_TIME_FORMATTER.format(dateTime);
     }
+
+    public static String getStartDateTime() {
+        try {
+            RuntimeMXBean runtimeMXBean = ManagementFactory.getRuntimeMXBean();
+            long startTime = runtimeMXBean.getStartTime();
+            Instant startInstant = Instant.ofEpochMilli(startTime);
+            LocalDateTime startDateTime = LocalDateTime.ofInstant(startInstant, ZoneId.systemDefault());
+            return DATE_TIME_FORMATTER.format(startDateTime);
+        } catch (Throwable e) {
+            return "unknown";
+        }
+    }
 }