create or load a destination from a file

host-cache/src/main/groovy/com/muwire/hostcache/HostCache.groovy

@@ -1,9 +1,45 @@
 package com.muwire.hostcache
 
+import net.i2p.client.I2PClientFactory
+import net.i2p.util.SystemVersion
+
 public class HostCache {
 
     public static void main(String[] args) {
-        print "Hello world"
+        if (SystemVersion.isWindows()) {
+            println "This will likely not run on windows"
+            System.exit(1)
+        }
+            
+        def home = System.getProperty("user.home") + "/.MuWireHostCache"
+        home = new File(home)
+        if (home.exists() && !home.isDirectory()) {
+            println "${home} exists but not a directory?  Delete it or make it a directory"
+            System.exit(1)
+        }
+        
+        if (!home.exists()) {
+            home.mkdir()
+        }
+        
+        def keyfile = new File(home, "key.dat")
+        
+        def i2pClientFactory = new I2PClientFactory()
+        def i2pClient = i2pClientFactory.createClient()
+        
+        def myDest
+        def session
+        if (!keyfile.exists()) {
+            def os = new FileOutputStream(keyfile);
+            myDest = i2pClient.createDestination(os)
+            os.close()
+            println "No key.dat file was found, so creating a new destination."
+            println "This is the destination you want to give out for your new HostCache"
+            println myDest.toBase64()
+        } 
+        
+        session = i2pClient.createSession(new FileInputStream(keyfile), System.getProperties())
+        myDest = session.getMyDestination()
     }
 
 }