From 7b0c82e0cd8c9844909bc6ddb8c0dabac457ef5f Mon Sep 17 00:00:00 2001
From: Matt Sicker <boards@gmail.com>
Date: Sun, 2 Feb 2014 21:43:04 -0600
Subject: [PATCH] Fix LOG4J2-475

---
 .../core/appender/db/nosql/mongo/MongoDBConnection.java     | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/db/nosql/mongo/MongoDBConnection.java b/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/db/nosql/mongo/MongoDBConnection.java
index 26dd2de..cef8d30 100644
--- a/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/db/nosql/mongo/MongoDBConnection.java
+++ b/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/db/nosql/mongo/MongoDBConnection.java
@@ -21,6 +21,7 @@ import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.core.appender.AppenderLoggingException;
 import org.apache.logging.log4j.core.appender.db.nosql.NoSQLConnection;
 import org.apache.logging.log4j.core.appender.db.nosql.NoSQLObject;
+import org.apache.logging.log4j.core.helpers.Strings;
 import org.apache.logging.log4j.status.StatusLogger;
 import org.bson.BSON;
 import org.bson.Transformer;
@@ -41,7 +42,7 @@ public final class MongoDBConnection implements NoSQLConnection<BasicDBObject, M
     private static final Logger LOGGER = StatusLogger.getLogger();
 
     static {
-        BSON.addDecodingHook(Level.class, new Transformer() {
+        BSON.addEncodingHook(Level.class, new Transformer() {
             @Override
             public Object transform(Object o) {
                 if (o instanceof Level) {
@@ -50,6 +51,12 @@ public final class MongoDBConnection implements NoSQLConnection<BasicDBObject, M
                 return o;
             }
         });
+        BSON.addDecodingHook(Level.class, new Transformer() {
+            @Override
+            public Object transform(final Object o) {
+                return Level.getLevel(String.valueOf(o));
+            }
+        });
     }
 
     private final DBCollection collection;
@@ -76,9 +83,9 @@ public final class MongoDBConnection implements NoSQLConnection<BasicDBObject, M
     public void insertObject(final NoSQLObject<BasicDBObject> object) {
         try {
             final WriteResult result = this.collection.insert(object.unwrap(), this.writeConcern);
-            if (result.getError() != null && result.getError().length() > 0) {
+            if (Strings.isNotEmpty(result.getError())) {
                 throw new AppenderLoggingException("Failed to write log event to MongoDB due to error: " +
-                        result.getError() + ".");
+                        result.getError() + '.');
             }
         } catch (final MongoException e) {
             throw new AppenderLoggingException("Failed to write log event to MongoDB due to error: " + e.getMessage(),
-- 
1.8.5.3