diff --git a/core/src/main/java/com/taobao/arthas/core/util/ObjectUtils.java b/core/src/main/java/com/taobao/arthas/core/util/ObjectUtils.java
index 6a6d57b61..6cbdd9314 100644
--- a/core/src/main/java/com/taobao/arthas/core/util/ObjectUtils.java
+++ b/core/src/main/java/com/taobao/arthas/core/util/ObjectUtils.java
@@ -444,12 +444,10 @@ public abstract class ObjectUtils {
             if(length == 0) {
                 return "{}";
             } else {
-                StringBuilder sb = new StringBuilder();
+                StringBuilder sb = new StringBuilder("{");
 
                 for(int i = 0; i < length; ++i) {
-                    if(i == 0) {
-                        sb.append("{");
-                    } else {
+                    if(i > 0) {
                         sb.append(", ");
                     }
 
@@ -470,12 +468,10 @@ public abstract class ObjectUtils {
             if(length == 0) {
                 return "{}";
             } else {
-                StringBuilder sb = new StringBuilder();
+                StringBuilder sb = new StringBuilder("{");
 
                 for(int i = 0; i < length; ++i) {
-                    if(i == 0) {
-                        sb.append("{");
-                    } else {
+                    if(i > 0) {
                         sb.append(", ");
                     }
 
@@ -496,12 +492,10 @@ public abstract class ObjectUtils {
             if(length == 0) {
                 return "{}";
             } else {
-                StringBuilder sb = new StringBuilder();
+                StringBuilder sb = new StringBuilder("{");
 
                 for(int i = 0; i < length; ++i) {
-                    if(i == 0) {
-                        sb.append("{");
-                    } else {
+                    if(i > 0) {
                         sb.append(", ");
                     }
 
@@ -522,12 +516,10 @@ public abstract class ObjectUtils {
             if(length == 0) {
                 return "{}";
             } else {
-                StringBuilder sb = new StringBuilder();
+                StringBuilder sb = new StringBuilder("{");
 
                 for(int i = 0; i < length; ++i) {
-                    if(i == 0) {
-                        sb.append("{");
-                    } else {
+                    if(i > 0) {
                         sb.append(", ");
                     }
 
@@ -548,12 +540,10 @@ public abstract class ObjectUtils {
             if(length == 0) {
                 return "{}";
             } else {
-                StringBuilder sb = new StringBuilder();
+                StringBuilder sb = new StringBuilder("{");
 
                 for(int i = 0; i < length; ++i) {
-                    if(i == 0) {
-                        sb.append("{");
-                    } else {
+                    if(i > 0) {
                         sb.append(", ");
                     }
 
@@ -574,12 +564,10 @@ public abstract class ObjectUtils {
             if(length == 0) {
                 return "{}";
             } else {
-                StringBuilder sb = new StringBuilder();
+                StringBuilder sb = new StringBuilder("{");
 
                 for(int i = 0; i < length; ++i) {
-                    if(i == 0) {
-                        sb.append("{");
-                    } else {
+                    if(i > 0) {
                         sb.append(", ");
                     }
 
@@ -600,12 +588,10 @@ public abstract class ObjectUtils {
             if(length == 0) {
                 return "{}";
             } else {
-                StringBuilder sb = new StringBuilder();
+                StringBuilder sb = new StringBuilder("{");
 
                 for(int i = 0; i < length; ++i) {
-                    if(i == 0) {
-                        sb.append("{");
-                    } else {
+                    if(i > 0) {
                         sb.append(", ");
                     }
 
@@ -626,12 +612,10 @@ public abstract class ObjectUtils {
             if(length == 0) {
                 return "{}";
             } else {
-                StringBuilder sb = new StringBuilder();
+                StringBuilder sb = new StringBuilder("{");
 
                 for(int i = 0; i < length; ++i) {
-                    if(i == 0) {
-                        sb.append("{");
-                    } else {
+                    if(i > 0) {
                         sb.append(", ");
                     }
 
@@ -652,12 +636,10 @@ public abstract class ObjectUtils {
             if(length == 0) {
                 return "{}";
             } else {
-                StringBuilder sb = new StringBuilder();
+                StringBuilder sb = new StringBuilder("{");
 
                 for(int i = 0; i < length; ++i) {
-                    if(i == 0) {
-                        sb.append("{");
-                    } else {
+                    if(i > 0) {
                         sb.append(", ");
                     }