From 5b2de72f6cd3cd06845cd2ccd4e762cd8c320f54 Mon Sep 17 00:00:00 2001
From: "shrek.wang" <shrek.wang@gmail.com>
Date: Thu, 30 Aug 2012 10:52:22 +0800
Subject: [PATCH] fixes nullpoint problem if no sqlstat data when execute cmd
 tool

---
 .../druid/stat/DruidStatManagerFacade.java     |  4 +++-
 .../druid/support/console/DruidStat.java       | 12 ++++++++++--
 .../alibaba/druid/support/console/Option.java  | 18 +++++++++++++++++-
 3 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/src/main/java/com/alibaba/druid/stat/DruidStatManagerFacade.java b/src/main/java/com/alibaba/druid/stat/DruidStatManagerFacade.java
index 1891eb4092..7c9cfb9bfe 100644
--- a/src/main/java/com/alibaba/druid/stat/DruidStatManagerFacade.java
+++ b/src/main/java/com/alibaba/druid/stat/DruidStatManagerFacade.java
@@ -183,7 +183,9 @@ public final class DruidStatManagerFacade {
         List<List<String>> traceList = new ArrayList<List<String>>();
         for (Object dataSource : getDruidDataSourceInstances()) {
             List<String> stacks = ((DruidDataSource) dataSource).getActiveConnectionStackTrace();
-            traceList.add(stacks);
+			if (stacks.size() > 0 ) {
+				traceList.add(stacks);
+			}
         }
         return traceList;
     }
diff --git a/src/main/java/com/alibaba/druid/support/console/DruidStat.java b/src/main/java/com/alibaba/druid/support/console/DruidStat.java
index 6f922e1835..aca6aa9ccb 100644
--- a/src/main/java/com/alibaba/druid/support/console/DruidStat.java
+++ b/src/main/java/com/alibaba/druid/support/console/DruidStat.java
@@ -74,12 +74,20 @@ public class DruidStat {
         
         if (option.printSqlData()) {
             List<Map<String, Object>> content = (List<Map<String, Object>>) invokeService(jmxConn, Option.SQL);
-            TabledDataPrinter.printSqlData(content, option);
+			if (content == null ) { 
+				System.out.println("无SqlStat统计数据,请检查是否已执行了SQL");
+			} else {
+				TabledDataPrinter.printSqlData(content, option);
+			}
         }
        
         if (option.printActiveConn()) {
             List<List<String>> content = (List<List<String>>) invokeService(jmxConn, Option.ACTIVE_CONN);
-            TabledDataPrinter.printActiveConnStack(content, option);
+			if (content == null || content.size() == 0 ) {
+				System.out.println("目前无活动中的数据库连接");
+			} else {
+				TabledDataPrinter.printActiveConnStack(content, option);
+			}
         }
         
     }
diff --git a/src/main/java/com/alibaba/druid/support/console/Option.java b/src/main/java/com/alibaba/druid/support/console/Option.java
index efa4f5d3c4..b358f26792 100644
--- a/src/main/java/com/alibaba/druid/support/console/Option.java
+++ b/src/main/java/com/alibaba/druid/support/console/Option.java
@@ -155,10 +155,26 @@ public class Option {
 
         System.out.println();
         System.out.println("说明: ");
-        System.out.println("  -sql,-ds,-act参数中要至少指定一种数据进行打印, 可以组合使用, 比如 -sql -ds 一起的话就打印两种统计数据");
+        System.out.println("  -sql,-ds,-act参数中要至少指定一种数据进行打印, 可以");
+        System.out.println("    组合使用, 比如 -sql -ds 一起的话就打印两种统计数据");
         System.out.println("  -id id可以跟 -sql 或-ds组合, 比如  -sql -id 5 或 -ds -id 1086752");
         System.out.println("  pid必需指定, refresh-interval可选, 如不指定,则打印数据后退出");
         System.out.println("  pid和refresh-interval参数必需放在命令行的最后, 否则解析会出错");
+
+        System.out.println();
+        System.out.println("例子: ");
+        System.out.println("  打印3983进程的sql 统计数据.");
+        System.out.println("      >druidStat -sql 3983");
+        System.out.println("  打印3983进程的ds统计数据.");
+        System.out.println("      >druidStat -ds 3983");
+        System.out.println("  打印3983进程的sql的id为10的详细统计数据.");
+        System.out.println("      >druidStat -sql -id 10 -detail 3983");
+        System.out.println("  打印3983进程的当前活动连接的堆栈信息");
+        System.out.println("      >druidStat -act 3983");
+        System.out.println("  打印3983进程的ds,sql,和act信息");
+        System.out.println("      >druidStat -ds -sql -act 3983");
+        System.out.println("  每隔5秒自动打印ds统计数据");
+        System.out.println("      >druidStat -ds 3983 5");
 	}
 
 	public int getId() {