depend on com.fasterxml.jackson.core 2.8.4

pom.xml

diff --git a/pom.xml b/pom.xml
index 3f1f390..cc8884f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -378,6 +378,12 @@
             </dependency>
 
             <dependency>
+                <groupId>com.fasterxml.jackson.core</groupId>
+                <artifactId>jackson-core</artifactId>
+                <version>2.8.4</version>
+            </dependency>
+
+            <dependency>
                 <groupId>commons-io</groupId>
                 <artifactId>commons-io</artifactId>
                 <version>2.4</version>

vxquery-core/pom.xml

diff --git a/vxquery-core/pom.xml b/vxquery-core/pom.xml
index 920a195..47015a9 100644
--- a/vxquery-core/pom.xml
+++ b/vxquery-core/pom.xml
@@ -252,6 +252,11 @@
         </dependency>
 
         <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-core</artifactId>
+        </dependency>
+
+        <dependency>
             <groupId>commons-io</groupId>
             <artifactId>commons-io</artifactId>
         </dependency>

vxquery-core/src/main/java/org/apache/vxquery/jsonparser/JSONParser.java

diff --git a/vxquery-core/src/main/java/org/apache/vxquery/jsonparser/JSONParser.java b/vxquery-core/src/main/java/org/apache/vxquery/jsonparser/JSONParser.java
index 68fbb82..ad8db4e 100644
--- a/vxquery-core/src/main/java/org/apache/vxquery/jsonparser/JSONParser.java
+++ b/vxquery-core/src/main/java/org/apache/vxquery/jsonparser/JSONParser.java
@@ -20,9 +20,6 @@
 import java.util.ArrayList;
 import java.util.List;
 
-import org.apache.htrace.fasterxml.jackson.core.JsonFactory;
-import org.apache.htrace.fasterxml.jackson.core.JsonParser;
-import org.apache.htrace.fasterxml.jackson.core.JsonToken;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
 import org.apache.hyracks.data.std.primitive.UTF8StringPointable;
 import org.apache.hyracks.data.std.util.ArrayBackedValueStorage;
@@ -33,6 +30,10 @@
 import org.apache.vxquery.datamodel.values.ValueTag;
 import org.apache.vxquery.xmlparser.IParser;
 
+import com.fasterxml.jackson.core.JsonFactory;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonToken;
+
 public class JSONParser implements IParser {
 
     final JsonFactory factory;

vxquery-core/src/main/java/org/apache/vxquery/runtime/functions/util/FunctionHelper.java

diff --git a/vxquery-core/src/main/java/org/apache/vxquery/runtime/functions/util/FunctionHelper.java b/vxquery-core/src/main/java/org/apache/vxquery/runtime/functions/util/FunctionHelper.java
index 85f519e..49e1271 100644
--- a/vxquery-core/src/main/java/org/apache/vxquery/runtime/functions/util/FunctionHelper.java
+++ b/vxquery-core/src/main/java/org/apache/vxquery/runtime/functions/util/FunctionHelper.java
@@ -16,7 +16,6 @@
  */
 package org.apache.vxquery.runtime.functions.util;
 
-import java.io.BufferedReader;
 import java.io.DataInputStream;
 import java.io.DataOutput;
 import java.io.File;
@@ -32,8 +31,6 @@
 
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
-import org.apache.htrace.fasterxml.jackson.core.JsonParseException;
-import org.apache.hyracks.api.exceptions.HyracksDataException;
 import org.apache.hyracks.data.std.api.IPointable;
 import org.apache.hyracks.data.std.primitive.DoublePointable;
 import org.apache.hyracks.data.std.primitive.LongPointable;