Issue Scenario:Issue in Fetching VTN Dataflows, 500 internal server error returned when GET operation is performed using Query string from VTN Coordinator.

Reproduce the BUG:

Controller:

curl -v --user admin:adminpass -H 'content-type: application/json' -X POST -d '{"controller": {"controller_id": "odc", "ipaddr":"10.106.138.191", "type": "odc", "version": "1.0", "auditstatus":"enable"}}' http://127.0.0.1:8083/vtn-webapi/controllers.json

VTN:

curl -v --user admin:adminpass -H 'content-type: application/json' -X POST -d '{"vtn" : {"vtn_name":"vtn1","description":"test VTN" }}' http://127.0.0.1:8083/vtn-webapi/vtns.json

VBRIDGE:

curl -v --user admin:adminpass -H 'content-type: application/json' -X POST -d '{"vbridge" : {"vbr_name":"vBridge1","controller_id":"odc","domain_id":"(DEFAULT)","description": "creating vbrif update" }}' http://127.0.0.1:8083/vtn-webapi/vtns/vtn1/vbridges.json

INTERFACES:

curl --user admin:adminpass -H 'content-type: application/json' -X POST -d '{"interface": {"if_name": "if2","description": "if_desc1"}}' http://127.0.0.1:8083/vtn-webapi/vtns/vtn1/vbridges/vBridge1/interfaces.json

curl --user admin:adminpass -H 'content-type: application/json' -X POST -d '{"interface": {"if_name": "if1","description": "if_desc1"}}' http://127.0.0.1:8083/vtn-webapi/vtns/vtn1/vbridges/vBridge1/interfaces.json

PORTMAPPING:

curl -v --user admin:adminpass -H 'content-type: application/json' -X PUT -d '{"portmap":{"logical_port_id": "PP-OF:openflow:2-s2-eth1"}}' http://127.0.0.1:8083/vtn-webapi/vtns/vtn1/vbridges/vBridge1/interfaces/if2/portmap.json

curl -v --user admin:adminpass -H 'content-type: application/json' -X PUT -d '{"portmap":{"logical_port_id": "PP-OF:openflow:3-s3-eth1"}}' http://127.0.0.1:8083/vtn-webapi/vtns/vtn1/vbridges/vBridge1/interfaces/if1/portmap.json

THEN Give Ping in mininet (topo tree-2 level script) for h1 to h3:

Now GET command with Query string:

curl -v -X GET -H 'content-type: application/json' --user 'admin:adminpass' -H 'ipaddr:127.0.0.1' "http://127.0.0.1:8083/vtn-webapi/vtns/vtn1/dataflows?vnode_name=vBridge1&srcmacaddr=4690.da0b.3a29&no_vlan_id=true"

THE COORDINATOR LOGS:

2016-01-14 23:31:02.613480: [26799]: INFO: odcdriver: write to cache succes
2016-01-14 23:31:02.613503: [26799]: INFO: dataflow: 12. flow_count=1
2016-01-14 23:31:02.613557: [26799]: TRACE: dataflow: inside sessOutDataflow fn with getres_pos as 13
2016-01-14 23:31:02.613776: [26799]: DEBUG: dataflow: 13. [VAL_FLOW_CMN: valid: 111111111111111111001 ]
controller_name: odc
controller_type: 5
flow_id: 14
created_time: 2147483647
idle_timeout: 300
hard_timeout:0
ingress_vnode: vBridge1
ingress_vinterface: if2
ingress_switch_id: openflow:2
ingress_port_id: s2-eth1
ingress_logical_port_id: PP-openflow2-s2-eth1
ingress_domain: (DEFAULT)
egress_vnode: vBridge1
egress_vinterface: if1
egress_switch_id: openflow:3
egress_port_id: s3-eth1
egress_logical_port_id: PP-openflow3-s3-eth1
egress_domain: (DEFAULT)
match_count: 2
action_count: 0
path_info_count: 1

2016-01-14 23:31:02.613823: [26799]: DEBUG: dataflow: 14. [VAL_FLOW_MATCH: match_type: 1 ]

2016-01-14 23:31:02.613856: [26799]: DEBUG: dataflow: 15. [VAL_FLOW_MATCH_DL_ADDR: dl_addr: 4690.da0b.3a29, v_mask: 0, dl_addr_mask: 0000.0000.0000 ]

2016-01-14 23:31:02.613868: [26799]: DEBUG: dataflow: 16. [VAL_FLOW_MATCH: match_type: 2 ]

2016-01-14 23:31:02.613878: [26799]: DEBUG: dataflow: 17. [VAL_FLOW_MATCH_DL_ADDR: dl_addr: 6e9e.c20d.b568, v_mask: 0, dl_addr_mask: 0000.0000.0000 ]

2016-01-14 23:31:02.613886: [26799]: TRACE: dataflow: inside sessOutDataflow fn sending actions after match struct sessout.
2016-01-14 23:31:02.613903: [26799]: DEBUG: dataflow: 18. [VAL_FLOW_PATH_INFO: valid: 111111 ]
in_vnode: vBridge1
in_vif: if2
out_vnode: vBridge1
out_vif: if1
vlink_flag: 1
status: 0

2016-01-14 23:31:02.613914: [26799]: DEBUG: dataflow: Return value 0
2016-01-14 23:31:02.613922: [26799]: TRACE: dataflow: DataflowCmn -Destructor call
2016-01-14 23:31:02.613935: [26799]: TRACE: dataflow: DataflowCmn - Destructor call end
2016-01-14 23:31:02.613943: [26799]: DEBUG: dataflow: sessOutDataflowsFromDriver befor df_segment delete
2016-01-14 23:31:02.613948: [26799]: TRACE: dataflow: DataflowDetail -Destructor call
2016-01-14 23:31:02.613954: [26799]: TRACE: dataflow: out_matches map entry is deleted
2016-01-14 23:31:02.613958: [26799]: TRACE: dataflow: out_matches map entry is deleted
2016-01-14 23:31:02.613964: [26799]: TRACE: dataflow: vtn_path_infos vector entry is deleted
2016-01-14 23:31:02.613972: [26799]: DEBUG: dataflow: ~DataflowUtil ctrlr_dom_count_map.size=0 firstCtrlrFlows.size=0 pfc_flows.size=0