diff --git a/packet/const.go b/packet/const.go
index 8772508..72dcd9f 100644
--- a/packet/const.go
+++ b/packet/const.go
@@ -1,5 +1,7 @@
 package packet
 
+import "errors"
+
 const (
 	//publish类型 缓存最小大小
 	PUBLISH_CACHE_MINLENGTH = 1024 * 1024 * 1024
@@ -120,3 +122,10 @@ const (
 	PARSE_NOT_ENOUGH_LACK        //解析字节不够，下次提供新增字节
 	PARSE_REMAINDER              //剩余字节
 )
+
+var (
+	// ErrNoTopic PUBLISH 未设置主题
+	ErrNoTopic = errors.New("PUBLISH 未设置主题")
+	// 主题包含U+0000字符
+	ErrTopicU0000 = errors.New("主题包含U+0000字符")
+)
diff --git a/packet/packet_test.go b/packet/packet_test.go
index 8c215e6..ac27dc7 100644
--- a/packet/packet_test.go
+++ b/packet/packet_test.go
@@ -82,7 +82,7 @@ func TestPublishPacketAndUnPacket(t *testing.T) {
 		newconn.remlen = int(datalen)
 		fmt.Printf("%X\n", tmp[1+clen:])
 		newconn.UnPacket(tmp[0], tmp[1+clen:])
-		fmt.Printf("解析后结果:\n%s", newconn)
+		fmt.Printf("解析后结果:\n%v", newconn)
 
 	}
 
diff --git a/packet/publish.go b/packet/publish.go
index f023ab2..0820241 100644
--- a/packet/publish.go
+++ b/packet/publish.go
@@ -5,7 +5,6 @@
 package packet
 
 import (
-	"errors"
 	"fmt"
 	"io"
 	"time"
@@ -209,7 +208,7 @@ func formatPayload(payload []byte) string {
 	return fmt.Sprintf("(%d)%X", len(payload), payload[0:n])
 }
 func (c *Publish) String() string {
-	return fmt.Sprintf("PUBLISH重发标志:%t 服务质量等级(Qos):%d 保留标志:%t 主题名:%s 报文标志:%d  接收时间:%v有效载荷:%s", c.GetDupFlag(), c.GetQos(), c.GetRetain(), c.topic, c.packetId, c.ReciveStartTime, formatPayload(c.payload))
+	return fmt.Sprintf("PUBLISH DUP:%t QoS:%d Retain:%t Topic:%s id:%d time:%v payload:%s", c.GetDupFlag(), c.GetQos(), c.GetRetain(), c.topic, c.packetId, c.ReciveStartTime, formatPayload(c.payload))
 }
 
 //解包
@@ -217,6 +216,9 @@ func (c *Publish) UnPacket(header byte, msg []byte) error {
 	c.cache = false
 
 	c.remlen = len(msg)
+	if c.remlen < 2 {
+		return ErrNoTopic
+	}
 	// c.SetRetain(header&0x1 == 0x1)
 	// c.SetQos(QoS(header >> 1 & 0x3))
 	// c.SetDupFlag(header&0x8 == 0x8)
@@ -232,7 +234,7 @@ func (c *Publish) UnPacket(header byte, msg []byte) error {
 	}
 
 	if !util.VerifyZeroByMqtt([]rune(c.GetTopicByString())) {
-		return errors.New("主题包含U+0000字符关闭连接")
+		return ErrTopicU0000
 	}
 	//c.setBuffByRemdata(msg)
 	return nil