alter language to kotlin

src/java/com/wasteinformationserver/website/MainPage.kt

@@ -0,0 +1,56 @@
+package com.wasteinformationserver.website
+
+import com.sun.net.httpserver.HttpExchange
+import com.sun.net.httpserver.HttpHandler
+import com.wasteinformationserver.basicutils.Log.Log.debug
+import com.wasteinformationserver.basicutils.Log.Log.warning
+import com.wasteinformationserver.website.datarequests.login.LoginState
+import java.io.IOException
+
+class MainPage : HttpHandler {
+    @Throws(IOException::class)
+    override fun handle(t: HttpExchange) {
+        var path = t.requestURI.path
+        if (path == "/") {
+            path += "index.html"
+        }
+        debug("looking for: $path")
+        if (path.contains(".html")) {
+            if (LoginState.getObject().isLoggedIn || path == "/register.html" || path == "/index.html") { //pass only register page
+                sendPage(path, t)
+            } else {
+                warning("user not logged in --> redirecting to login page")
+                sendPage("/index.html", t)
+            }
+        } else { //only detect login state on html pages
+            sendPage(path, t)
+        }
+    }
+
+    @Throws(IOException::class)
+    private fun sendPage(path: String, t: HttpExchange) {
+        val fs = javaClass.getResourceAsStream("/wwwroot$path")
+        if (fs == null && path.contains(".html")) {
+            warning("wrong page sending 404")
+            sendPage("/404Error.html", t)
+        } else if (fs == null) {
+            warning("requested resource doesnt exist --> $path")
+        } else { // Object exists and is a file: accept with response code 200.
+            var mime = "text/html"
+            val s = path.substring(path.length - 3)
+            if (s == ".js") mime = "application/javascript"
+            if (s == "css") mime = "text/css"
+            val h = t.responseHeaders
+            h["Content-Type"] = mime
+            t.sendResponseHeaders(200, 0)
+            val os = t.responseBody
+            val buffer = ByteArray(0x10000)
+            var count: Int
+            while (fs.read(buffer).also { count = it } >= 0) {
+                os.write(buffer, 0, count)
+            }
+            fs.close()
+            os.close()
+        }
+    }
+}