Improve handling of HTTP responses

Makes it so that responses area all uniformly JSON and wrapped
into the proper response envelope.

src/main/java/org/asamk/signal/http/HttpServerException.java

@@ -0,0 +1,14 @@
+package org.asamk.signal.http;
+
+public class HttpServerException extends RuntimeException {
+
+    private int httpStatus;
+
+    public HttpServerException(final int aHttpStatus, final String message) {
+        super(message);
+    }
+
+    public int getHttpStatus() {
+        return httpStatus;
+    }
+}

src/main/java/org/asamk/signal/http/HttpServerHandler.java

@@ -1,8 +1,10 @@
 package org.asamk.signal.http;
 
+import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.node.ContainerNode;
 import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.fasterxml.jackson.databind.node.POJONode;
 import com.sun.net.httpserver.HttpExchange;
 import com.sun.net.httpserver.HttpServer;
 
@@ -11,10 +13,10 @@ import org.asamk.signal.commands.JsonRpcNamespace;
 import org.asamk.signal.commands.LocalCommand;
 import org.asamk.signal.commands.MultiLocalCommand;
 import org.asamk.signal.commands.RegistrationCommand;
+import org.asamk.signal.commands.exceptions.CommandException;
 import org.asamk.signal.jsonrpc.JsonRpcException;
 import org.asamk.signal.jsonrpc.JsonRpcRequest;
 import org.asamk.signal.jsonrpc.JsonRpcResponse;
-import org.asamk.signal.jsonrpc.SignalJsonRpcDispatcherHandler;
 import org.asamk.signal.manager.Manager;
 import org.asamk.signal.manager.MultiAccountManager;
 import org.asamk.signal.manager.RegistrationManager;
@@ -27,13 +29,12 @@ import java.io.IOException;
 import java.io.StringWriter;
 import java.net.InetSocketAddress;
 import java.nio.channels.OverlappingFileLockException;
-import java.nio.charset.StandardCharsets;
 import java.util.Map;
 import java.util.concurrent.Executors;
 
 public class HttpServerHandler {
 
-    private final static Logger logger = LoggerFactory.getLogger(SignalJsonRpcDispatcherHandler.class);
+    private final static Logger logger = LoggerFactory.getLogger(HttpServerHandler.class);
 
     private final ObjectMapper objectMapper = Util.createJsonObjectMapper();
 
@@ -41,26 +42,76 @@ public class HttpServerHandler {
 
         try {
 
-            System.out.println("Starting server on port " + port);
+            logger.info("Starting server on port " + port);
 
             final var server = HttpServer.create(new InetSocketAddress(port), 0);
             server.setExecutor(Executors.newFixedThreadPool(10));
 
             server.createContext("/api/v1", httpExchange -> {
+
+                JsonRpcRequest request = null;
+
                 try {
                     if (!"POST".equals(httpExchange.getRequestMethod())) {
-                        sendResponse(405, "NOT SUPPORTED", httpExchange);
+                        throw new HttpServerException(405, "Method not supported.");
                     }
 
-                    final var request = objectMapper.readValue(httpExchange.getRequestBody(), JsonRpcRequest.class);
+                    request = objectMapper.readValue(httpExchange.getRequestBody(), JsonRpcRequest.class);
                     final Map params = objectMapper.treeToValue(request.getParams(), Map.class);
 
-                    System.out.println("Command called " + request.getMethod());
+                    logger.debug("Command called " + request.getMethod());
 
-                    final var command = Commands.getCommand(request.getMethod());
-                    final var writer = new StringWriter();
                     final var ns = new JsonRpcNamespace(params);
 
+                    final var responseBody = processRequest(m, ns, request);
+
+                    sendResponse(200, responseBody, httpExchange);
+
+                }
+                catch (JsonRpcException aEx) {
+                    logger.error("Failed to process request.", aEx);
+                    sendResponse(500, JsonRpcResponse.forError(aEx.getError(), request.getId()), httpExchange);
+                }
+                catch (HttpServerException aEx) {
+                    logger.error("Failed to process request.", aEx);
+                    sendResponse(aEx.getHttpStatus(), JsonRpcResponse.forError(
+                            new JsonRpcResponse.Error(JsonRpcResponse.Error.INVALID_REQUEST,
+                                    aEx.getMessage(), null), null), httpExchange);
+                }
+                catch (Throwable aEx) {
+                    logger.error("Failed to process request.", aEx);
+                    sendResponse(500, JsonRpcResponse.forError(
+                            new JsonRpcResponse.Error(JsonRpcResponse.Error.INTERNAL_ERROR,
+                            "An internal server error has occured.", null), null), httpExchange);
+                }
+            });
+
+            server.start();
+
+            // TODO there may be a better way to keep the main thread running.
+            try {
+                while (true) {
+                    Thread.sleep(1000);
+                }
+            } catch (InterruptedException ex) { }
+
+            logger.info("Server shut down");
+
+        } catch (Throwable ex) {
+            ex.printStackTrace();
+        }
+
+    }
+
+    private JsonRpcResponse processRequest(
+            final MultiAccountManager m,
+            final JsonRpcNamespace ns,
+            final JsonRpcRequest request
+    ) throws JsonRpcException, CommandException, IOException {
+
+        final var writer = new StringWriter();
+        final var command = Commands.getCommand(request.getMethod());
+
         if (command instanceof LocalCommand) {
             final var manager = getManagerFromParams(request.getParams(), m);
             ((LocalCommand) command).handleCommand(ns, manager, new JsonWriterImpl(writer));
@@ -77,40 +128,25 @@ public class HttpServerHandler {
             }
         }
         else {
-                        sendResponse(404, "COMMAND NOT FOUND", httpExchange);
+            throw new JsonRpcException(new JsonRpcResponse.Error(JsonRpcResponse.Error.METHOD_NOT_FOUND,
-                        return;
+                    "The specified method is not supported.",
+                    null));
         }
 
-                    // TODO if writer empty return some generic response
+        final var rawJson = writer.toString();
-                    sendResponse(200, writer.toString(), httpExchange);
+        final JsonNode dataNode;
 
-                }
+        if (rawJson.isEmpty()) {
-                catch (Throwable aEx) {
+            dataNode = new POJONode(new HttpSimpleResponse("OK"));
-                    aEx.printStackTrace();
+        } else {
-                    //TODO if this is a JSON RPC Error serialize and return the error
+            dataNode = objectMapper.readTree(rawJson);
-                    sendResponse(500, "ERROR", httpExchange);
-                }
-            });
-
-            server.start();
-
-            // TODO there may be a better way to keep the main thread running.
-            try {
-                while (true) {
-                    Thread.sleep(1000);
-                }
-            } catch (InterruptedException ex) { }
-
-            System.out.println("Server shut down");
-
-        } catch (Throwable ex) {
-            ex.printStackTrace();
         }
 
+        return JsonRpcResponse.forSuccess(dataNode, request.getId());
     }
 
-    private void sendResponse(int status, String body, HttpExchange httpExchange) throws IOException {
+    private void sendResponse(int status, JsonRpcResponse response, HttpExchange httpExchange) throws IOException {
-        final var byteResponse = body.getBytes(StandardCharsets.UTF_8);
+        final var byteResponse = objectMapper.writeValueAsBytes(response);
         httpExchange.sendResponseHeaders(status, byteResponse.length);
         httpExchange.getResponseBody().write(byteResponse);
         httpExchange.getResponseBody().close();

src/main/java/org/asamk/signal/http/HttpSimpleResponse.java

@@ -0,0 +1,3 @@
+package org.asamk.signal.http;
+
+public record HttpSimpleResponse(String status) {}