feat: add used demo

README.md

@@ -1,2 +1,39 @@
 # gocommon
-golang common tools set
+This repository relies only on standard libraries.
+
+### crypto/aes
+```go
+var ecb128pkcs7 = aes.New([]byte("1234567890123456"))
+ecb128pkcs7.Encrypt([]byte("msg"))
+ecb128pkcs7.Bytes()
+ecb128pkcs7.Error
+
+var buf,e = aes.Encrypt([]byte("1234567890123456"), []byte("msg"))
+```
+### crypto/rsa 
+### injects 
+```go
+package xxstore
+
+type store struct{}
+
+func init(){
+	injects.Service.Register(&store{}, &injects.Config{Name:"store:mysql", Step: 10})
+}
+```
+### otp
+```go
+
+var totp = otp.NewTOTP("secret", otp.TOTPWithPeriod(60))
+var code, _ = totp.Generate()
+var ok, _ = totp.Validate(code)
+var url = totp.URL("Gcommon", "testid") // return url string. encode qrcode for scan 2FA.
+```
+### encoding/json 
+```go
+var buf = []byte(`{"a":1,"b":"hello","c":false,"d":{"a":1.234}}`)
+var m,_ = json.Parse(buf) 
+// map[a:1 b:hello c:false d:map[a:1.234]]
+buf,_ = json.Stringify(m)
+// []byte({"d":{"a":1.234},"a":1,"b":"hello","c":false})
+```