radom string

 package common
 
 import (
+	"bytes"
 	"fmt"
 	"encoding/json"
+	"math/rand"
 )
 
 // Must panics if err is not nil.
@@ -33,4 +35,17 @@ func AssertJson(object interface{})string{
 		return ""
 	}
 	return string(json)
+}
+
+var randomChars = "ABCDEFGHJKMNPQRSTWXYZabcdefhjkmnprstwxyz2345678" /****默认去掉了容易混淆的字符oOLl,9gq,Vv,Uu,I1****/
+func RandomString(l int)string{
+	if l<=0{
+		return ""
+	}
+	lenChars :=len(randomChars) -1
+	rsp :=bytes.NewBuffer(nil)
+	for i:=0;i<l;i++{
+		rsp.WriteByte(randomChars[rand.Intn(lenChars)])
+	}
+	return rsp.String()
 }
\ No newline at end of file

+package common
+
+import (
+	"testing"
+)
+
+func Test_RandomString(t *testing.T){
+	input :=[]int{6,10,20,16,32}
+	for i:=range input{
+		l :=input[i]
+		out := RandomString(l)
+		if len(out)!=l{
+			t.Fatal("length not equal want :",l," out:",out)
+		}
+	}
+}
+
+func Benchmark_RandomString(b *testing.B) {
+	input :=[]int{10,20,16,32}
+	l :=0
+	out :=""
+	for i:=0;i<b.N;i++{
+		l=i%4
+		l=input[l]
+		out = RandomString(l)
+		if len(out)!=l{
+			b.Fatal("length not equal want :",l," out:",out)
+		}
+	}
+}
\ No newline at end of file