Backports User-Agent header changes (#154)

Author: jchen293

CHANGELOG

@@ -1,3 +1,6 @@
+=== Next Release
+- Backports User-Agent header changes
+
 === 4.0.4 2020-10-29
 - Actually bump User-Agent (which hadn't been bumped since 4.0.0)
 

src/main/java/com/easypost/net/EasyPostResource.java

@@ -148,29 +148,25 @@ private static String urlEncodePair(String k, String v) throws UnsupportedEncodi
 	static Map<String, String> getHeaders(String apiKey) {
 		Map<String, String> headers = new HashMap<String, String>();
 		headers.put("Accept-Charset", CHARSET);
-		headers.put("User-Agent", String.format("EasyPost/v2 JavaClient/%s", EasyPost.VERSION));
+		headers.put("User-Agent", String.format("EasyPost/v2 JavaClient/%s Java/%s OS/%s OSVersion/%s OSArch/%s " +
+                "Implementation/%s", EasyPost.VERSION, System.getProperty("java.version"),
+                convertSpaceToHyphen(System.getProperty("os.name")), System.getProperty("os.version"),
+                convertSpaceToHyphen(System.getProperty("os.arch")),
+                convertSpaceToHyphen(System.getProperties().getProperty("java.vm.name"))));
 
 		if (apiKey == null) {
 			apiKey = EasyPost.apiKey;
 		}
 
 		headers.put("Authorization", String.format("Bearer %s", apiKey));
 
-		// debug headers
-		String[] propertyNames = { "os.name", "os.version", "os.arch",
-			"java.version", "java.vendor", "java.vm.version",
-			"java.vm.vendor" };
-		Map<String, String> propertyMap = new HashMap<String, String>();
-		for (String propertyName : propertyNames) {
-			propertyMap.put(propertyName, System.getProperty(propertyName));
-		}
-		propertyMap.put("lang", "Java");
-		propertyMap.put("publisher", "EasyPost");
-		headers.put("X-Client-User-Agent", gson.toJson(propertyMap));
-
-		return headers;
+        return headers;
 	}
 
+    private static String convertSpaceToHyphen(String string) {
+        return string.replace(' ', '-');
+    }
+
 	private static javax.net.ssl.HttpsURLConnection createEasyPostConnection(String url, String apiKey) throws IOException {
 		URL easypostURL = null;
 		String customURLStreamHandlerClassName = System.getProperty(CUSTOM_URL_STREAM_HANDLER_PROPERTY_NAME, null);