Do not autogenerate Version class on every compile.

Instead, use a properties template file and Maven filtering
to set the correct version while building the output jar.
At runtime, load the properties file from the classpath and
statically initialize the version parameter.

pom.xml

@@ -36,6 +36,12 @@
   <dependencies/>
 
   <build>
+    <resources>
+      <resource>
+        <directory>src/main/resources</directory>
+        <filtering>true</filtering>
+      </resource>
+    </resources>
     <plugins>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>

src/main/java/org/umlgraph/doclet/Version.java

@@ -0,0 +1,29 @@
+package org.umlgraph.doclet;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Properties;
+
+class Version {
+    private final static String filename = "version.properties";
+    private final static String key = "umlgraph.version";
+    public static String VERSION;
+
+    static {
+        Properties props = new Properties();
+        InputStream in = Version.class.getClassLoader().getResourceAsStream(filename);
+        try {
+            props.load(in);
+            if (props.get(key) == null) {
+                System.err.println("Could not find version property");
+                VERSION = "0";
+            } else {
+                VERSION = props.get(key).toString();
+            }
+
+            in.close();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}

src/main/resources/version.properties

@@ -0,0 +1 @@
+umlgraph.version=${pom.version}