diff --git a/src/gaea.app/src/main/kotlin/com/synebula/gaea/app/ILogin.kt b/src/gaea.app/src/main/kotlin/com/synebula/gaea/app/ILogin.kt
deleted file mode 100644
index 22a30ff..0000000
--- a/src/gaea.app/src/main/kotlin/com/synebula/gaea/app/ILogin.kt
+++ /dev/null
@@ -1,15 +0,0 @@
-package com.synebula.gaea.app
-
-import com.synebula.gaea.data.message.Message
-
-
-interface ILogin {
-    /**
-     * 定义登录方法。
-     *
-     * @param name 登录名
-     * @param password 登录密码
-     * @return StatusMessage, data 内容为 map 其中 key account中存储用户账户名称
-     */
-    fun login(name: String, password: String): Message<Any>
-}
diff --git a/src/gaea.app/src/main/kotlin/com/synebula/gaea/app/ISignInOut.kt b/src/gaea.app/src/main/kotlin/com/synebula/gaea/app/ISignInOut.kt
new file mode 100644
index 0000000..098ff75
--- /dev/null
+++ b/src/gaea.app/src/main/kotlin/com/synebula/gaea/app/ISignInOut.kt
@@ -0,0 +1,24 @@
+package com.synebula.gaea.app
+
+import org.springframework.http.HttpMessage
+
+/**
+ * 用户登入登出接口定义
+ */
+interface ISignInOut {
+    /**
+     * 定义登录方法。
+     *
+     * @param name 登录名
+     * @param password 登录密码
+     * @return StatusMessage, data 内容为 map 其中 key account中存储用户账户名称
+     */
+    fun signIn(name: String, password: String): HttpMessage
+
+    /**
+     * 登出
+     *
+     * @param user 登出的用户
+     */
+    fun signOut(user: String): HttpMessage
+}
diff --git a/src/gaea/src/main/kotlin/com/synebula/gaea/extension/StringExt.kt b/src/gaea/src/main/kotlin/com/synebula/gaea/extension/StringExt.kt
index bbb7df2..490d14f 100644
--- a/src/gaea/src/main/kotlin/com/synebula/gaea/extension/StringExt.kt
+++ b/src/gaea/src/main/kotlin/com/synebula/gaea/extension/StringExt.kt
@@ -1,9 +1,32 @@
 package com.synebula.gaea.extension
 
+import java.math.BigInteger
+import java.security.MessageDigest
+import java.security.NoSuchAlgorithmException
+
+/**
+ * 首字母小写
+ */
 fun String.firstCharLowerCase(): String {
-    if (Character.isLowerCase(this.elementAt(0)))
-        return this
+    return if (Character.isLowerCase(this.elementAt(0)))
+        this
     else
-        return StringBuilder().append(Character.toLowerCase(this.elementAt(0)))
+        StringBuilder().append(Character.toLowerCase(this.elementAt(0)))
                 .append(this.substring(1)).toString()
-}
\ No newline at end of file
+}
+
+/**
+ * 获取字符串的MD值
+ */
+fun String.toMd5(): String {
+    val secretBytes = try {
+        MessageDigest.getInstance("md5").digest(this.toByteArray())
+    } catch (e: NoSuchAlgorithmException) {
+        throw RuntimeException("没有这个md5算法！")
+    }
+    var md5code = BigInteger(1, secretBytes).toString(16)
+    for (i in 0 until 32 - md5code.length) {
+        md5code = "0$md5code"
+    }
+    return md5code
+}