Implement Globalstar protocol

1 files changed, 119 insertions, 0 deletions

diff --git a/src/main/java/org/traccar/protocol/GlobalstarProtocolDecoder.java b/src/main/java/org/traccar/protocol/GlobalstarProtocolDecoder.java
new file mode 100644
index 000000000..ab9e5dccf
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/GlobalstarProtocolDecoder.java
@@ -0,0 +1,119 @@
+/*
+ * Copyright 2019 Anton Tananaev (anton@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.protocol;
+
+import com.fasterxml.jackson.databind.util.ByteBufferBackedInputStream;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
+import io.netty.handler.codec.http.FullHttpRequest;
+import io.netty.handler.codec.http.HttpResponseStatus;
+import org.traccar.BaseHttpProtocolDecoder;
+import org.traccar.DeviceSession;
+import org.traccar.Protocol;
+import org.traccar.helper.DataConverter;
+import org.traccar.model.Position;
+import org.w3c.dom.Document;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.xpath.XPath;
+import javax.xml.xpath.XPathConstants;
+import javax.xml.xpath.XPathExpression;
+import javax.xml.xpath.XPathExpressionException;
+import javax.xml.xpath.XPathFactory;
+import java.net.SocketAddress;
+import java.util.Date;
+import java.util.LinkedList;
+import java.util.List;
+
+public class GlobalstarProtocolDecoder extends BaseHttpProtocolDecoder {
+
+    private DocumentBuilder documentBuilder;
+    private XPath xPath;
+    private XPathExpression messageExpression;
+
+    public GlobalstarProtocolDecoder(Protocol protocol) {
+        super(protocol);
+        try {
+            DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
+            builderFactory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
+            builderFactory.setFeature("http://xml.org/sax/features/external-general-entities", false);
+            builderFactory.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
+            builderFactory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
+            builderFactory.setXIncludeAware(false);
+            builderFactory.setExpandEntityReferences(false);
+            documentBuilder = builderFactory.newDocumentBuilder();
+            xPath = XPathFactory.newInstance().newXPath();
+            messageExpression = xPath.compile("//stuMessages/stuMessage");
+        } catch (ParserConfigurationException | XPathExpressionException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    @Override
+    protected Object decode(
+            Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {
+
+        FullHttpRequest request = (FullHttpRequest) msg;
+
+        Document document = documentBuilder.parse(new ByteBufferBackedInputStream(request.content().nioBuffer()));
+        NodeList nodes = (NodeList) messageExpression.evaluate(document, XPathConstants.NODESET);
+
+        List<Position> positions = new LinkedList<>();
+
+        for (int i = 0; i < nodes.getLength(); i++) {
+            Node node = nodes.item(i);
+            DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, xPath.evaluate("esn", node));
+            if (deviceSession != null) {
+
+                Position position = new Position(getProtocolName());
+                position.setDeviceId(deviceSession.getDeviceId());
+
+                position.setValid(true);
+                position.setTime(new Date(Long.parseLong(xPath.evaluate("unixTime", node)) * 1000));
+
+                ByteBuf buf = Unpooled.wrappedBuffer(
+                        DataConverter.parseHex(xPath.evaluate("payload", node).substring(2)));
+
+                buf.readUnsignedByte(); // flags
+
+                position.setLatitude(buf.readUnsignedMedium() * 90.0 / (1 << 23));
+                if (position.getLatitude() > 90) {
+                    position.setLatitude(position.getLatitude() - 180);
+                }
+
+                position.setLongitude(buf.readUnsignedMedium() * 90.0 / (1 << 23));
+                if (position.getLongitude() > 180) {
+                    position.setLongitude(position.getLongitude() - 360);
+                }
+
+                buf.readUnsignedByte(); // status
+                buf.readUnsignedByte(); // status
+
+                positions.add(position);
+
+            }
+        }
+
+        sendResponse(channel, HttpResponseStatus.OK);
+        return positions;
+    }
+
+}