Read client version from version.properties file

Author: technige

java-client/src/main/java/co/elastic/clients/base/UserAgent.java

@@ -19,20 +19,42 @@
 
 package co.elastic.clients.base;
 
+import java.io.IOException;
+import java.io.InputStream;
 import java.util.Collections;
 import java.util.Map;
+import java.util.Properties;
 
 /**
  * Models a user agent, consisting of a name, version,
  * and optional key-value metadata.
  */
 public class UserAgent {
 
-    // TODO: move this to a resource file
     static final String DEFAULT_NAME = "elasticsearch-java";
 
-    // TODO: move this to a resource file
-    static final String DEFAULT_VERSION = "1.2.3";
+    // The client version is loaded from the 'version.properties' file
+    static final String DEFAULT_VERSION;
+    static {
+        InputStream in = UserAgent.class.getResourceAsStream("/co.elastic.clients.elasticsearch/version.properties");
+        if (in != null) {
+            Properties prop = new Properties();
+            String version;
+            try {
+                prop.load(in);
+                version = prop.getProperty("version", "?");
+            } catch (IOException e) {
+                // Unable to read properties file
+                version = "?";
+            }
+            DEFAULT_VERSION = version;
+        }
+        else {
+            // Unable to locate properties file
+            DEFAULT_VERSION = "?";
+        }
+        // TODO: log error if DEFAULT_VERSION now equals "?"
+    }
 
     // Default user agent, constructed from default repo name and version
     public static final UserAgent DEFAULT = new UserAgent(DEFAULT_NAME, DEFAULT_VERSION);