Implement jsonRpc command

Co-authored-by: technillogue <technillogue@gmail.com>

Closes #668

src/main/java/org/asamk/signal/jsonrpc/JsonRpcResponse.java

@@ -0,0 +1,120 @@
+package org.asamk.signal.jsonrpc;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ValueNode;
+
+/**
+ * Represents a JSON-RPC response.
+ * https://www.jsonrpc.org/specification#response_object
+ */
+public class JsonRpcResponse extends JsonRpcMessage {
+
+    /**
+     * A String specifying the version of the JSON-RPC protocol. MUST be exactly "2.0".
+     */
+    String jsonrpc;
+
+    /**
+     * This member is REQUIRED on success.
+     * This member MUST NOT exist if there was an error invoking the method.
+     * The value of this member is determined by the method invoked on the Server.
+     */
+    @JsonInclude(JsonInclude.Include.NON_NULL)
+    JsonNode result;
+
+    /**
+     * This member is REQUIRED on error.
+     * This member MUST NOT exist if there was no error triggered during invocation.
+     * The value for this member MUST be an Object as defined in section 5.1.
+     */
+    @JsonInclude(JsonInclude.Include.NON_NULL)
+    Error error;
+
+    /**
+     * This member is REQUIRED.
+     * It MUST be the same as the value of the id member in the Request Object.
+     * If there was an error in detecting the id in the Request object (e.g. Parse error/Invalid Request), it MUST be Null.
+     */
+    ValueNode id;
+
+    public static JsonRpcResponse forSuccess(JsonNode result, ValueNode id) {
+        return new JsonRpcResponse("2.0", result, null, id);
+    }
+
+    public static JsonRpcResponse forError(Error error, ValueNode id) {
+        return new JsonRpcResponse("2.0", null, error, id);
+    }
+
+    private JsonRpcResponse() {
+    }
+
+    private JsonRpcResponse(final String jsonrpc, final JsonNode result, final Error error, final ValueNode id) {
+        this.jsonrpc = jsonrpc;
+        this.result = result;
+        this.error = error;
+        this.id = id;
+    }
+
+    public String getJsonrpc() {
+        return jsonrpc;
+    }
+
+    public JsonNode getResult() {
+        return result;
+    }
+
+    public Error getError() {
+        return error;
+    }
+
+    public ValueNode getId() {
+        return id;
+    }
+
+    public static class Error {
+
+        public static final int PARSE_ERROR = -32700;
+        public static final int INVALID_REQUEST = -32600;
+        public static final int METHOD_NOT_FOUND = -32601;
+        public static final int INVALID_PARAMS = -32602;
+        public static final int INTERNAL_ERROR = -32603;
+
+        /**
+         * A Number that indicates the error type that occurred.
+         * This MUST be an integer.
+         */
+        int code;
+
+        /**
+         * A String providing a short description of the error.
+         * The message SHOULD be limited to a concise single sentence.
+         */
+        String message;
+
+        /**
+         * A Primitive or Structured value that contains additional information about the error.
+         * This may be omitted.
+         * The value of this member is defined by the Server (e.g. detailed error information, nested errors etc.).
+         */
+        JsonNode data;
+
+        public Error(final int code, final String message, final JsonNode data) {
+            this.code = code;
+            this.message = message;
+            this.data = data;
+        }
+
+        public int getCode() {
+            return code;
+        }
+
+        public String getMessage() {
+            return message;
+        }
+
+        public JsonNode getData() {
+            return data;
+        }
+    }
+}