oracle - SQL error 17002 : Physical DB connection is invalid -

i trying connect oracle db(installed in remote machine) java application. but, getting sql error code 17022. pls let me know how solve issue.

full stack trace

msg: connecting jdbc:oracle:thin:@(description=(address_list=(address=(protocol=tcp)(host=dlocdb04)(port=50000))(address=(protocol=tcp)(host=dlocdb04)(port=50000)))(connect_data=(service_name=os02rtdb01svc.world)(server=dedicated))) oracle jdbc driver version: 9.2.0.1.0 [cumulative retries=0]      user_id: unknown      level: warn       date: 2015-09-21 10:51:45,563  category: com.retek.merch.utils.connectionpool  msg: [sql error code: 17002, state: null] physical db connection invalid. restarting pool due following error.      user_id: unknown  java.sql.sqlexception: io exception: connection refused(description=(err=1153)(vsnnum=0)(error_stack=(error=(code=1153)(emfi=4)(args='(description=(address=(protocol=tcp)(host=dlocdb0401)(port=27320))(connect_data=(cid=(program=)(host=__jdbc__)(user=))null))'))(error=(code=303)(emfi=1))))     @ oracle.jdbc.dbaccess.dberror.throwsqlexception(dberror.java:134)     @ oracle.jdbc.dbaccess.dberror.throwsqlexception(dberror.java:179)     @ oracle.jdbc.dbaccess.dberror.throwsqlexception(dberror.java:333)     @ oracle.jdbc.driver.oracleconnection.<init>(oracleconnection.java:404)     @ oracle.jdbc.driver.oracledriver.getconnectioninstance(oracledriver.java:468)     @ oracle.jdbc.driver.oracledriver.connect(oracledriver.java:314)     @ java.sql.drivermanager.getconnection(drivermanager.java:512)     @ java.sql.drivermanager.getconnection(drivermanager.java:140)     @ oracle.jdbc.pool.oracledatasource.getconnection(oracledatasource.java:169)     @ oracle.jdbc.pool.oracleconnectionpooldatasource.getphysicalconnection(oracleconnectionpooldatasource.java:149)     @ oracle.jdbc.pool.oracleconnectionpooldatasource.getpooledconnection(oracleconnectionpooldatasource.java:95)     @ oracle.jdbc.pool.oracleconnectionpooldatasource.getpooledconnection(oracleconnectionpooldatasource.java:63)     @ oracle.jdbc.pool.oracleconnectioncacheimpl.getnewpoolorxaconnection(oracleconnectioncacheimpl.java:547)     @ oracle.jdbc.pool.oracleconnectioncacheimpl.getpooledconnection(oracleconnectioncacheimpl.java:404)     @ oracle.jdbc.pool.oracleconnectioncacheimpl.getconnection(oracleconnectioncacheimpl.java:298)     @ oracle.jdbc.pool.oracleconnectioncacheimpl.getconnection(oracleconnectioncacheimpl.java:268)     @ com.retek.merch.utils.connectionpool.get(connectionpool.java:346)     @ com.retek.merch.utils.transactionmanager.start(transactionmanager.java:59)     @ com.retek.reim.merch.utils.reimtransactionmanager.start(reimtransactionmanager.java:49)     @ com.retek.reim.manager.loginmanager.login(loginmanager.java:72)     @ com.retek.reim.ui.login.loginaction.perform(loginaction.java:47)     @ org.apache.struts.action.actionservlet.processactionperform(actionservlet.java:1786)     @ org.apache.struts.action.actionservlet.process(actionservlet.java:1585)     @ org.apache.struts.action.actionservlet.dopost(actionservlet.java:509)     @ javax.servlet.http.httpservlet.service(httpservlet.java:638)     @ javax.servlet.http.httpservlet.service(httpservlet.java:720)     @ org.apache.catalina.core.applicationfilterchain.internaldofilter(applicationfilterchain.java:199)     @ org.apache.catalina.core.applicationfilterchain.dofilter(applicationfilterchain.java:145)     @ org.apache.catalina.core.standardwrappervalve.invoke(standardwrappervalve.java:210)     @ org.apache.catalina.core.standardpipeline$standardpipelinevalvecontext.invokenext(standardpipeline.java:596)     @ org.apache.catalina.core.standardpipeline.invoke(standardpipeline.java:433)     @ org.apache.catalina.core.containerbase.invoke(containerbase.java:955)     @ org.apache.catalina.core.standardcontextvalve.invoke(standardcontextvalve.java:139)     @ org.apache.catalina.core.standardpipeline$standardpipelinevalvecontext.invokenext(standardpipeline.java:596)     @ org.apache.catalina.core.standardpipeline.invoke(standardpipeline.java:433)     @ org.apache.catalina.core.containerbase.invoke(containerbase.java:955)     @ org.apache.catalina.core.standardcontext.invoke(standardcontext.java:2460)     @ org.apache.catalina.core.standardhostvalve.invoke(standardhostvalve.java:133)     @ org.apache.catalina.core.standardpipeline$standardpipelinevalvecontext.invokenext(standardpipeline.java:596)     @ org.apache.catalina.valves.errordispatchervalve.invoke(errordispatchervalve.java:119)     @ org.apache.catalina.core.standardpipeline$standardpipelinevalvecontext.invokenext(standardpipeline.java:594)     @ org.apache.catalina.valves.errorreportvalve.invoke(errorreportvalve.java:116)     @ org.apache.catalina.core.standardpipeline$standardpipelinevalvecontext.invokenext(standardpipeline.java:594)     @ org.apache.catalina.core.standardpipeline.invoke(standardpipeline.java:433)     @ org.apache.catalina.core.containerbase.invoke(containerbase.java:955)     @ org.apache.catalina.core.standardenginevalve.invoke(standardenginevalve.java:127)     @ org.apache.catalina.core.standardpipeline$standardpipelinevalvecontext.invokenext(standardpipeline.java:596)     @ org.apache.catalina.core.standardpipeline.invoke(standardpipeline.java:433)     @ org.apache.catalina.core.containerbase.invoke(containerbase.java:955)     @ org.apache.coyote.tomcat4.coyoteadapter.service(coyoteadapter.java:157)     @ org.apache.coyote.http11.http11processor.process(http11processor.java:873)     @ org.apache.coyote.http11.http11baseprotocol$http11connectionhandler.processconnection(http11baseprotocol.java:665)     @ org.apache.tomcat.util.net.pooltcpendpoint.processsocket(pooltcpendpoint.java:528)     @ org.apache.tomcat.util.net.leaderfollowerworkerthread.runit(leaderfollowerworkerthread.java:81)     @ org.apache.tomcat.util.threads.threadpool$controlrunnable.run(threadpool.java:689)     @ java.lang.thread.run(thread.java:534)