Too many connections already

I am connecting to a remote postgres database (version 9.0) using sleep mode. I get the following error

2011-03-08 06: 48: 25,695 ERROR [org.hibernate.util.JDBCExceptionReporter] (http-69.89.2.245-8080-9) FATAL: sorry, too many clients already
2011-03-08 06: 48: 25,695 ERROR [org.apache.catalina.core.ContainerBase. [Jboss.web]. [Localhost]. [/ JBOSSINI]. [Com.java.misc.feedback]] (http- 69.89.2.245-8080-9) Servlet.service () for servlet com.java.misc.feedback threw exception: java.lang.NullPointerException
    at com.java.model.HiberEx.InsertsimpleReport (HiberEx.java:95) [:]
    at com.java.misc.feedback.doGet (feedback.java:87) [:]
    at javax.servlet.http.HttpServlet.service (HttpServlet.java:734) [: 1.0.0.Final]
    at javax.servlet.http.HttpServlet.service (HttpServlet.java:847) [: 1.0.0.Final]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter (ApplicationFilterChain.java:324) [: 6.0.0.Final]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter (ApplicationFilterChain.java:242) [: 6.0.0.Final]
    at org.apache.catalina.core.StandardWrapperValve.invoke (StandardWrapperValve.java:275) [: 6.0.0.Final]
    at org.apache.catalina.core.StandardContextValve.invoke (StandardContextValve.java:191) [: 6.0.0.Final]
    at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke (SecurityAssociationValve.java:181) [: 6.0.0.Final]
    at org.jboss.modcluster.catalina.CatalinaContext $ RequestListenerValve.event (CatalinaContext.java:285) [: 1.1.0.Final]
    at org.jboss.modcluster.catalina.CatalinaContext $ RequestListenerValve.invoke (CatalinaContext.java:261) [: 1.1.0.Final]
    at org.jboss.web.tomcat.security.JaccContextValve.invoke (JaccContextValve.java:88) [: 6.0.0.Final]
    at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke (SecurityContextEstablishmentValve.java:100) [: 6.0.0.Final]
    at org.apache.catalina.core.StandardHostValve.invoke (StandardHostValve.java:127) [: 6.0.0.Final]
    at org.apache.catalina.valves.ErrorReportValve.invoke (ErrorReportValve.java:102) [: 6.0.0.Final]
    at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke (CachedConnectionValve.java:158) [: 6.0.0.Final]
    at org.apache.catalina.core.StandardEngineValve.invoke (StandardEngineValve.java:109) [: 6.0.0.Final]
    at org.jboss.web.tomcat.service.request.ActiveRequestResponseCacheValve.invoke (ActiveRequestResponseCacheValve.java:53) [: 6.0.0.Final]
    at org.apache.catalina.connector.CoyoteAdapter.service (CoyoteAdapter.javahaps62) [: 6.0.0.Final]
    at org.apache.coyote.http11.Http11Processor.process (Http11Processor.java:877) [: 6.0.0.Final]
    at org.apache.coyote.http11.Http11Protocol $ Http11ConnectionHandler.process (Http11Protocol.java:654) [: 6.0.0.Final]
    at org.apache.tomcat.util.net.JIoEndpoint $ Worker.run (JIoEndpoint.java:951) [: 6.0.0.Final]
    at java.lang.Thread.run (Thread.java:619) [: 1.6.0_21]

this is my code

public void InsertfailReport (String destination, 
                String source
                String status,
                String timedate, String smsc,
                String failreason,
                String smsid,
                String message){
                SessionFactory sessionFactory = new Configuration().configure("com/java/hibernate.cfg.xml").buildSessionFactory();
                Session session = sessionFactory.openSession();
                Transaction transaction = null;

                try {
                    transaction = session.beginTransaction();
                    Failreport sobj=new Failreport();
                    sobj.setDestination(destination);
                    sobj.setFailreason(failreason);
                    sobj.setMessage(message);
                    sobj.setSmsc(smsc);
                    sobj.setSmsid(smsid);
                    sobj.setSource(source);
                    sobj.setStatus(status);
                    sobj.setTimedate(timedate);
                    session.save(sobj);
                    transaction.commit();
                } catch (HibernateException e) {
                    transaction.rollback();
                    e.printStackTrace();
                } finally {
                    session.close();
                }
        }

hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory name="MyFactory">
        <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
        <property name="hibernate.connection.password">xxxx</property>
        <property name="hibernate.connection.url">jdbc:postgresql://xx.xx.xx.xx:5432/smslog</property>
        <property name="hibernate.connection.username">xxxxx</property>
        <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
        <property name="hibernate.validator.apply_to_ddl">false</property>
        <property name="hibernate.validator.autoregister_listeners">false</property>
        <property name="hibernate.show_sql">true</property>
        <property name="hibernate.jdbc.batch_size">0</property>
          <mapping resource="com/java/model/Kannel.hbm.xml"/>
          <mapping resource="com/java/model/Smsc.hbm.xml"/>
          <mapping resource="com/java/model/Dlr.hbm.xml"/>
          <mapping resource="com/java/model/Routesmsc.hbm.xml"/>
          <mapping resource="com/java/model/Simplereport.hbm.xml"/>
          <mapping resource="com/java/model/Failreport.hbm.xml"/>
    </session-factory>
</hibernate-configuration>