diff --git a/src/Makefile b/src/Makefile
index 16a649f..27c6c5b 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -8,7 +8,12 @@ all: $(JAR) $(SHARED)
 JAVA_SOURCES=org/pEp/jniadapter/pEpException.java \
 			 org/pEp/jniadapter/AbstractEngine.java \
 			 org/pEp/jniadapter/Message.java \
-			 org/pEp/jniadapter/Engine.java
+			 org/pEp/jniadapter/Engine.java \
+			 org/pEp/jniadapter/Identity.java \
+			 org/pEp/jniadapter/_Identity.java \
+			 org/pEp/jniadapter/Blob.java \
+			 org/pEp/jniadapter/_Blob.java \
+			 org/pEp/jniadapter/CommType.java
 
 C_SOURCES=org_pEp_jniadapter_Engine.cc \
 		  org_pEp_jniadapter_Engine.h \
diff --git a/src/org/pEp/jniadapter/Blob.java b/src/org/pEp/jniadapter/Blob.java
index 4db23a9..d55e895 100644
--- a/src/org/pEp/jniadapter/Blob.java
+++ b/src/org/pEp/jniadapter/Blob.java
@@ -11,8 +11,10 @@ public class Blob {
 
     Blob(_Blob b) {
         data = b.data;
-        mime_type = AbstractEngine.toUTF16(b.mime_type);
-        filename = AbstractEngine.toUTF16(b.filename);
+        if (b.mime_type != null)
+            mime_type = AbstractEngine.toUTF16(b.mime_type);
+        if (b.filename != null)
+            filename = AbstractEngine.toUTF16(b.filename);
     }
 }
 
diff --git a/src/org/pEp/jniadapter/Identity.java b/src/org/pEp/jniadapter/Identity.java
index 40e8183..d5e98cf 100644
--- a/src/org/pEp/jniadapter/Identity.java
+++ b/src/org/pEp/jniadapter/Identity.java
@@ -11,19 +11,26 @@ public class Identity {
 
     public Identity() {
         this.me = false;
+        comm_type = CommType.PEP_ct_unknown;
     }
 
     public Identity(boolean me) {
         this.me = me;
+        comm_type = CommType.PEP_ct_unknown;
     }
 
     public Identity(_Identity i) {
-        address = AbstractEngine.toUTF16(i.address);
-        fpr = AbstractEngine.toUTF16(i.address);
-        user_id = AbstractEngine.toUTF16(i.address);
-        username = AbstractEngine.toUTF16(i.address);
+        if (i.address != null)
+            address = AbstractEngine.toUTF16(i.address);
+        if (i.fpr != null)
+            fpr = AbstractEngine.toUTF16(i.fpr);
+        if (i.user_id != null)
+            user_id = AbstractEngine.toUTF16(i.user_id);
+        if (i.username != null)
+            username = AbstractEngine.toUTF16(i.username);
         comm_type = CommType.Management.tag.get(i.comm_type);
-        lang = AbstractEngine.toUTF16(i.address);
+        if (i.lang != null)
+            lang = AbstractEngine.toUTF16(i.lang);
         me = i.me;
     }
 }
diff --git a/src/org/pEp/jniadapter/_Blob.java b/src/org/pEp/jniadapter/_Blob.java
index 9432781..c8c5fa5 100644
--- a/src/org/pEp/jniadapter/_Blob.java
+++ b/src/org/pEp/jniadapter/_Blob.java
@@ -9,8 +9,10 @@ public class _Blob {
 
     _Blob(Blob b) {
         data = b.data;
-        mime_type = AbstractEngine.toUTF8(b.mime_type);
-        filename = AbstractEngine.toUTF8(b.filename);
+        if (b.mime_type != null)
+            mime_type = AbstractEngine.toUTF8(b.mime_type);
+        if (b.filename != null)
+            filename = AbstractEngine.toUTF8(b.filename);
     }
 }
 
diff --git a/src/org/pEp/jniadapter/_Identity.java b/src/org/pEp/jniadapter/_Identity.java
index 980c77d..49e3707 100644
--- a/src/org/pEp/jniadapter/_Identity.java
+++ b/src/org/pEp/jniadapter/_Identity.java
@@ -18,12 +18,17 @@ public class _Identity {
     }
 
     public _Identity(Identity i) {
-        address = AbstractEngine.toUTF8(i.address);
-        fpr = AbstractEngine.toUTF8(i.address);
-        user_id = AbstractEngine.toUTF8(i.address);
-        username = AbstractEngine.toUTF8(i.address);
+        if (i.address != null)
+            address = AbstractEngine.toUTF8(i.address);
+        if (i.fpr != null)
+            fpr = AbstractEngine.toUTF8(i.fpr);
+        if (i.user_id != null)
+            user_id = AbstractEngine.toUTF8(i.user_id);
+        if (i.username != null)
+            username = AbstractEngine.toUTF8(i.username);
         comm_type = i.comm_type.value;
-        lang = AbstractEngine.toUTF8(i.address);
+        if (i.lang != null)
+            lang = AbstractEngine.toUTF8(i.lang);
         me = i.me;
     }
 }
diff --git a/test/Testing.java b/test/Testing.java
index 13668f4..dedc25f 100644
--- a/test/Testing.java
+++ b/test/Testing.java
@@ -1,16 +1,25 @@
 import org.pEp.jniadapter.Engine;
 import org.pEp.jniadapter.pEpException;
+import org.pEp.jniadapter.Identity;
 
 class Testing {
     public static void main(String[] args) {
+        Engine e;
+
+        // load
         try {
-            Engine e = new Engine();
+            e = new Engine();
         }
         catch (pEpException ex) {
             System.out.println("Cannot load");
             return;
         }
         System.out.println("Test loaded");
+
+        // trustwords
+        Identity vb = new Identity();
+        vb.fpr = "DB4713183660A12ABAFA7714EBE90D44146F62F4";
+        String t = e.trustwords(vb);
     }
 }