From 98194e83aa7696f5c0e6dd9e7c025657ea835731 Mon Sep 17 00:00:00 2001
From: Paul Speed <pspeed42@users.noreply.github.com>
Date: Tue, 22 Dec 2015 05:33:44 -0500
Subject: [PATCH] Modified the RPC layer to pass exceptions over the wire if
 they are serializable.  They are still wrapped but at least the original
 exception is intact if callers want to peel it out.

---
 .../network/service/rpc/RpcConnection.java    |  5 +++
 .../service/rpc/msg/RpcResponseMessage.java   | 38 ++++++++++++++++---
 2 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/jme3-networking/src/main/java/com/jme3/network/service/rpc/RpcConnection.java b/jme3-networking/src/main/java/com/jme3/network/service/rpc/RpcConnection.java
index f457e426b..0ced410c4 100644
--- a/jme3-networking/src/main/java/com/jme3/network/service/rpc/RpcConnection.java
+++ b/jme3-networking/src/main/java/com/jme3/network/service/rpc/RpcConnection.java
@@ -225,6 +225,7 @@ public class RpcConnection {
     private class ResponseHolder {
         private Object response;
         private String error;
+        private Throwable exception;
         private RpcCallMessage msg;
         boolean received = false;
  
@@ -235,6 +236,7 @@ public class RpcConnection {
         public synchronized void setResponse( RpcResponseMessage msg ) {
             this.response = msg.getResult();
             this.error = msg.getError();
+            this.exception = msg.getThrowable();
             this.received = true;
             notifyAll();
         }
@@ -250,6 +252,9 @@ public class RpcConnection {
             if( error != null ) {
                 throw new RuntimeException("Error calling remote procedure:" + msg + "\n" + error);
             }
+            if( exception != null ) {
+                throw new RuntimeException("Error calling remote procedure:" + msg, exception);
+            } 
             return response;              
         }
         
diff --git a/jme3-networking/src/main/java/com/jme3/network/service/rpc/msg/RpcResponseMessage.java b/jme3-networking/src/main/java/com/jme3/network/service/rpc/msg/RpcResponseMessage.java
index c8ca8083a..8e15514e7 100644
--- a/jme3-networking/src/main/java/com/jme3/network/service/rpc/msg/RpcResponseMessage.java
+++ b/jme3-networking/src/main/java/com/jme3/network/service/rpc/msg/RpcResponseMessage.java
@@ -34,6 +34,7 @@ package com.jme3.network.service.rpc.msg;
 
 import com.jme3.network.AbstractMessage;
 import com.jme3.network.serializing.Serializable;
+import com.jme3.network.serializing.Serializer;
 import java.io.PrintWriter;
 import java.io.StringWriter;
 
@@ -50,6 +51,7 @@ public class RpcResponseMessage extends AbstractMessage {
     private long msgId;
     private Object result;
     private String error;
+    private Object exception; // if it was serializable
 
     public RpcResponseMessage() {
     }
@@ -61,12 +63,31 @@ public class RpcResponseMessage extends AbstractMessage {
 
     public RpcResponseMessage( long msgId, Throwable t ) {
         this.msgId = msgId;
-         
-        StringWriter sOut = new StringWriter();
-        PrintWriter out = new PrintWriter(sOut);
-        t.printStackTrace(out);
-        out.close();
-        this.error = sOut.toString();
+ 
+        // See if the exception is serializable
+        if( isSerializable(t) ) {
+            // Can send the exception itself
+            this.exception = t;
+        } else {
+            // We'll compose all of the info into a string           
+            StringWriter sOut = new StringWriter();
+            PrintWriter out = new PrintWriter(sOut);
+            t.printStackTrace(out);
+            out.close();
+            this.error = sOut.toString();
+        }
+    }
+ 
+    public static boolean isSerializable( Throwable error ) {
+        if( error == null ) {
+            return false;
+        }
+        for( Throwable t = error; t != null; t = t.getCause() ) {
+            if( Serializer.getExactSerializerRegistration(t.getClass()) == null ) {
+                return false;
+            }
+        }
+        return true; 
     }
  
     public long getMessageId() {
@@ -81,10 +102,15 @@ public class RpcResponseMessage extends AbstractMessage {
         return error;
     }
     
+    public Throwable getThrowable() {
+        return (Throwable)exception;
+    }
+    
     @Override
     public String toString() {
         return getClass().getSimpleName() + "[#" + msgId + ", result=" + result
                                           + (error != null ? ", error=" + error : "")
+                                          + (exception != null ? ", exception=" + exception : "")
                                           + "]";
     }
 }