version properties , args, see main() comments for example usage.

Author: jayunit100

src/main/java/org/apache/hadoop/fs/glusterfs/Version.java

@@ -1,23 +1,51 @@
 package org.apache.hadoop.fs.glusterfs;
 
 import java.io.IOException;
-import java.util.Properties;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import java.util.Properties;
 
+/**
+ * Versioning stuff for the shim.  This class is not tested since there is no 
+ * deterministic behaviour (i.e. it might not work if not building from binary), 
+ * and the effects are pure side effects.
+ */
 public class Version extends Properties{
-    final static Logger lg = LoggerFactory.getLogger(Version.class);
     public Version() {
         super();
         try{
             load(this.getClass().getClassLoader().getResourceAsStream("git.properties"));
         }
         catch(Throwable t){
-            lg.error("Couldn't find git properties for version info " + t.getMessage());
+            throw new RuntimeException("Couldn't find git properties for version info " + t.getMessage());
         }
     }
     public String getTag(){
         return this.getProperty("git.commit.id.describe").split("-")[0];
     }
+    
+    /**
+     * For use with terminal version checking. 
+       
+       Example, run with an argument to get single property:
+             java -cp /home/Development/hadoop-glusterfs/glusterfs-2.0-SNAPSHOT.jar \
+                 org.apache.hadoop.fs.glusterfs.Version git.commit.id.describe | cut -d'-' -f 1     
+
+       Or just run (no args, prints all properties)
+             java -cp /home/Development/hadoop-glusterfs/glusterfs-2.0-SNAPSHOT.jar \
+    */
+    public static void main(String[] args){
+        Version v = new Version();
+        //Dump the whole version info if no arg
+        if(args.length==0){
+            System.out.println(v);
+        }
+        //if specific arg given, print just that.
+        else{
+            String prop = v.get(args[0])+"";
+            System.out.println(
+                    prop!=null?
+                        prop
+                        :"Couldnt find property "+prop);
+        }
+    }
 }