Removed json-simple library usages

Author: trinopoty

engine.io-server/src/main/java/io/socket/engineio/server/EngineIoServer.java

@@ -1,9 +1,9 @@
 package io.socket.engineio.server;
 
-import io.socket.engineio.server.json.JSONObject;
 import io.socket.engineio.server.parser.Parser;
 import io.socket.engineio.server.transport.Polling;
 import io.socket.engineio.server.transport.WebSocket;
+import io.socket.engineio.server.utils.JsonUtils;
 import io.socket.engineio.server.utils.ParseQS;
 import io.socket.engineio.server.utils.ServerYeast;
 
@@ -39,6 +39,8 @@ public interface HandshakeInterceptor {
         boolean intercept(Map<String, String> query, Map<String, List<String>> headers);
     }
 
+    private static final String ERROR_JSON = "{\"code\": %d, \"message\": \"%s\"}";
+
     private final Map<String, EngineIoSocket> mClients = new ConcurrentHashMap<>();
     private final EngineIoServerOptions mOptions;
     private final HashSet<String> mAllowedCorsOrigins;
@@ -231,19 +233,17 @@ private void sendErrorMessage(HttpServletResponse response,
         response.setCharacterEncoding(StandardCharsets.UTF_8.name());
 
         if(code != null) {
-            final JSONObject jsonObject = new JSONObject();
-            jsonObject.put("code", code.getCode());
-            jsonObject.put("message", code.getMessage());
-
             response.setStatus(400);
-            response.getWriter().write(JSONObject.toJSONString(jsonObject));
+            response.getWriter().write(String.format(
+                    ERROR_JSON,
+                    code.getCode(),
+                    JsonUtils.escape(code.getMessage())));
         } else {
-            final JSONObject jsonObject = new JSONObject();
-            jsonObject.put("code", ServerErrors.FORBIDDEN.getCode());
-            jsonObject.put("message", ServerErrors.FORBIDDEN.getMessage());
-
             response.setStatus(403);
-            response.getWriter().write(JSONObject.toJSONString(jsonObject));
+            response.getWriter().write(String.format(
+                    ERROR_JSON,
+                    ServerErrors.FORBIDDEN.getCode(),
+                    JsonUtils.escape(ServerErrors.FORBIDDEN.getMessage())));
         }
     }
 

engine.io-server/src/main/java/io/socket/engineio/server/EngineIoSocket.java

@@ -1,10 +1,9 @@
 package io.socket.engineio.server;
 
-import io.socket.engineio.server.json.JSONArray;
-import io.socket.engineio.server.json.JSONObject;
 import io.socket.engineio.server.parser.Packet;
 import io.socket.engineio.server.transport.Polling;
 import io.socket.engineio.server.transport.WebSocket;
+import io.socket.engineio.server.utils.JsonUtils;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
@@ -31,6 +30,10 @@ public interface SocketedListener {
         add(new Packet<>(Packet.NOOP));
     }};
 
+    private static final String EMPTY_UPGRADES = JsonUtils.toJson(new String[]{});
+    private static final String WEBSOCKET_UPGRADES = JsonUtils.toJson(new String[] { WebSocket.NAME });
+    private static final String HANDSHAKE_JSON = "{\"sid\": \"%s\", \"upgrades\": %s, \"pingInterval\": %d, \"pingTimeout\": %d}";
+
     private final String mSid;
     private final int mProtocolVersion;
     private final EngineIoServer mServer;
@@ -326,17 +329,20 @@ private void clearTransport() {
     private void onOpen() {
         mReadyState = ReadyState.OPEN;
 
-        JSONArray upgrades = new JSONArray();
-        upgrades.add(WebSocket.NAME);
-
-        JSONObject handshakePacket = new JSONObject();
-        handshakePacket.put("sid", mSid);
-        handshakePacket.put("upgrades", upgrades);
-        handshakePacket.put("pingInterval", mServer.getOptions().getPingInterval());
-        handshakePacket.put("pingTimeout", mServer.getOptions().getPingTimeout());
+        final String upgrades;
+        if (mTransport.getName().equals(Polling.NAME)) {
+            upgrades = WEBSOCKET_UPGRADES;
+        } else {
+            upgrades = EMPTY_UPGRADES;
+        }
 
         Packet<String> openPacket = new Packet<>(Packet.OPEN);
-        openPacket.data = JSONObject.toJSONString(handshakePacket);
+        openPacket.data = String.format(
+                HANDSHAKE_JSON,
+                JsonUtils.escape(mSid),
+                upgrades,
+                mServer.getOptions().getPingInterval(),
+                mServer.getOptions().getPingTimeout());
 
         sendPacket(openPacket);
 

engine.io-server/src/main/java/io/socket/engineio/server/utils/JsonUtils.java

@@ -0,0 +1,57 @@
+package io.socket.engineio.server.utils;
+
+import java.util.Arrays;
+import java.util.Locale;
+
+public interface JsonUtils {
+
+    /**
+     * Replacements for the first 255 characters
+     */
+    String[] REPLACEMENTS = new String[] {
+            "\\u0000", "\\u0001", "\\u0002", "\\u0003", "\\u0004", "\\u0005", "\\u0006", "\\u0007", "\\u0008", "\\u0009", "\\u000A", "\\u000B", "\\u000C", "\\u000D", "\\u000E", "\\u000F",
+            "\\u0010", "\\u0011", "\\u0012", "\\u0013", "\\u0014", "\\u0015", "\\u0016", "\\u0017", "\\u0018", "\\u0019", "\\u001A", "\\u001B", "\\u001C", "\\u001D", "\\u001E", "\\u001F",
+            null, null, "\\\"", null, null, null, null, null, null, null, null, null, null, null, null, null,
+            null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null,
+            null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null,
+            null, null, null, null, null, null, null, null, null, null, null, null, "\\\\", null, null, null,
+            null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null,
+            null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null,
+    };
+
+    String EMPTY_ARRAY = "[]";
+
+    static String toJson(String[] array) {
+        if (array.length <= 0) {
+            return EMPTY_ARRAY;
+        }
+
+        return '[' +
+                String.join(",", Arrays.stream(array).map(s -> "\"" + escape(s) + "\"").toArray(String[]::new)) +
+                ']';
+    }
+
+    static String escape(String input) {
+        if (input == null) {
+            return null;
+        }
+
+        final StringBuilder sb = new StringBuilder(input.length());
+        for (int i = 0; i < input.length(); i++) {
+            final char ch = input.charAt(i);
+            if (ch < 0x80) {
+                final String replacement = REPLACEMENTS[ch];
+                if (replacement != null) {
+                    sb.append(replacement);
+                    continue;
+                }
+            } else if (ch < 0x100) {
+                sb.append("\\u00").append(Integer.toHexString(ch).toLowerCase(Locale.ROOT));
+                continue;
+            }
+
+            sb.append(ch);
+        }
+        return sb.toString();
+    }
+}