fetch sql files and save Queries into List

src/main/kotlin/fr/postgresjson/connexion/Connection.kt

@@ -5,6 +5,7 @@ import com.github.jasync.sql.db.postgresql.PostgreSQLConnection
 import com.github.jasync.sql.db.postgresql.PostgreSQLConnectionBuilder
 import fr.postgresjson.entity.EntityI
 import fr.postgresjson.serializer.Serializer
+import java.io.File
 
 
 class Connection(
@@ -12,11 +13,24 @@ class Connection(
     private val port: Int = 5432,
     private val database: String = "dc-project",
     private val username: String = "dc-project",
-    private val password: String = "dc-project"
+    private val password: String = "dc-project",
+    queriesDirectory: File? = null
 ) {
+    private val queries = mutableMapOf<String, MutableMap<String, String>>()
     private lateinit var connection: ConnectionPool<PostgreSQLConnection>
     val serializer = Serializer()
 
+    init {
+        if (queriesDirectory === null) {
+            val resource = this::class.java.getResource("/sql/query")
+            if (resource !== null) {
+                fetchQueries(File(resource.toURI()))
+            }
+        } else {
+            fetchQueries(queriesDirectory)
+        }
+    }
+
     fun connect(): ConnectionPool<PostgreSQLConnection> {
         if (!::connection.isInitialized || !connection.isConnected()) {
             connection = PostgreSQLConnectionBuilder.createConnectionPool(
@@ -26,7 +40,13 @@ class Connection(
         return connection
     }
 
-    inline fun <T, reified R : EntityI<T?>> selectOne(sql: String, values: List<Any?> = emptyList()): R? {
+    inline fun <T, reified R : EntityI<T?>?> selectOne(group: String, name: String, values: List<Any?> = emptyList()): R? {
+        val sql: String = getQuery(group, name)
+
+        return selectOne<T, R>(sql, values)
+    }
+
+    inline fun <T, reified R : EntityI<T?>?> selectOne(sql: String, values: List<Any?> = emptyList()): R? {
         val future = connect().sendPreparedStatement(sql, values)
         val json = future.get().rows[0].getString(0)
         if (json === null) {
@@ -49,4 +69,24 @@ class Connection(
             return obj
         }
     }
+
+    private fun fetchQueries(queriesDirectory: File) {
+        queriesDirectory.walk().filter{it.isDirectory}.forEach { directory ->
+            val group = directory.name
+            directory.walk().filter{it.isFile}.forEach { file ->
+                val sql = file.readText()
+                if (queries[group] === null) {
+                    queries[group] = mutableMapOf()
+                }
+                queries[group]!![file.nameWithoutExtension] = sql
+            }
+        }
+    }
+
+    fun getQuery(group: String, name: String): String {
+        if (queries[group] === null || queries[group]!![name] === null) {
+            throw Exception("No query defined for $group/$name")
+        }
+        return queries[group]!![name]!!
+    }
 }