1 files changed, 59 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/StringProtocolEncoder.java b/src/main/java/org/traccar/StringProtocolEncoder.java
new file mode 100644
index 000000000..e9fb65500
--- /dev/null
+++ b/src/main/java/org/traccar/StringProtocolEncoder.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2015 - 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;
+
+import org.traccar.model.Command;
+
+public abstract class StringProtocolEncoder extends BaseProtocolEncoder {
+
+    public StringProtocolEncoder(Protocol protocol) {
+        super(protocol);
+    }
+
+    public interface ValueFormatter {
+        String formatValue(String key, Object value);
+    }
+
+    protected String formatCommand(Command command, String format, ValueFormatter valueFormatter, String... keys) {
+
+        Object[] values = new String[keys.length];
+        for (int i = 0; i < keys.length; i++) {
+            String value = null;
+            if (keys[i].equals(Command.KEY_UNIQUE_ID)) {
+                value = getUniqueId(command.getDeviceId());
+            } else {
+                Object object = command.getAttributes().get(keys[i]);
+                if (valueFormatter != null) {
+                    value = valueFormatter.formatValue(keys[i], object);
+                }
+                if (value == null && object != null) {
+                    value = object.toString();
+                }
+                if (value == null) {
+                    value = "";
+                }
+            }
+            values[i] = value;
+        }
+
+        return String.format(format, values);
+    }
+
+    protected String formatCommand(Command command, String format, String... keys) {
+        return formatCommand(command, format, null, keys);
+    }
+
+}