feat(metrics): 运行指标服务端支持设置 HTTP 认证.

支持对运行指标服务端设置 HTTP 认证, 以防止运行指标被非法获取.

scalabot-app/src/main/kotlin/util/UsernameAuthenticator.kt

@@ -0,0 +1,65 @@
+package net.lamgc.scalabot.util
+
+import com.google.gson.*
+import com.sun.net.httpserver.BasicAuthenticator
+import java.lang.reflect.Type
+
+class UsernameAuthenticator(private val username: String, private val password: String) :
+    BasicAuthenticator("metrics") {
+    override fun checkCredentials(username: String?, password: String?): Boolean =
+        this.username == username && this.password == password
+
+    fun toJsonObject(): JsonObject = JsonObject().apply {
+        addProperty("username", username)
+        addProperty("password", password)
+    }
+
+    override fun equals(other: Any?): Boolean {
+        return other is UsernameAuthenticator && this.username == other.username && this.password == other.password
+    }
+
+    override fun hashCode(): Int {
+        var result = username.hashCode()
+        result = 31 * result + password.hashCode()
+        return result
+    }
+
+}
+
+object UsernameAuthenticatorSerializer : JsonSerializer<UsernameAuthenticator>,
+    JsonDeserializer<UsernameAuthenticator> {
+
+    override fun serialize(
+        src: UsernameAuthenticator,
+        typeOfSrc: Type?,
+        context: JsonSerializationContext?
+    ): JsonElement {
+        return src.toJsonObject()
+    }
+
+    override fun deserialize(
+        json: JsonElement,
+        typeOfT: Type?,
+        context: JsonDeserializationContext?
+    ): UsernameAuthenticator? {
+        if (json.isJsonNull) {
+            return null
+        } else if (!json.isJsonObject) {
+            throw JsonParseException("Invalid attribute value type.")
+        }
+
+        val jsonObj = json.asJsonObject
+
+        if (jsonObj["username"]?.isJsonPrimitive != true) {
+            throw JsonParseException("Invalid attribute value: username")
+        } else if (jsonObj["password"]?.isJsonPrimitive != true) {
+            throw JsonParseException("Invalid attribute value: password")
+        }
+
+        if (jsonObj["username"].asString.isEmpty() || jsonObj["password"].asString.isEmpty()) {
+            throw JsonParseException("`username` or `password` is empty.")
+        }
+        return UsernameAuthenticator(jsonObj["username"].asString, jsonObj["password"].asString)
+    }
+
+}