log fix and abs hashcode

Author: dapeng

kafka-base/kafka-base-sink/src/main/java/com/dtstack/flink/sql/sink/kafka/CustomerFlinkPartition.java

@@ -22,11 +22,12 @@ public void open(int parallelInstanceId, int parallelInstances) {
 
     public int partition(T record, byte[] key, byte[] value, String targetTopic, int[] partitions) {
         Preconditions.checkArgument(partitions != null && partitions.length > 0, "Partitions of the target topic is empty.");
-        System.out.println("partitionKey=" + new String(key));
         if(key == null){
+            System.out.println("partitionKey=null");
             return partitions[this.parallelInstanceId % partitions.length];
         }
-        return partitions[new String(key).hashCode() % partitions.length];
+        System.out.println("partitionKey=" + new String(key));
+        return partitions[Math.abs(new String(key).hashCode()) % partitions.length];
     }
 
     public boolean equals(Object o) {