jdbc exception

java.lang.AbstractMethodError: org.postgresql.jdbc3g.Jdbc3gPreparedStatement.isClosed()Z
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.postgresql.ds.jdbc23.AbstractJdbc23PooledConnection$StatementHandler.invoke(AbstractJdbc23PooledConnection.java:453)
        at com.sun.proxy.$Proxy218.isClosed(Unknown Source)
        at com.sun.gjc.spi.jdbc40.PreparedStatementWrapper40.isClosed(PreparedStatementWrapper40.java:530)
        at com.xxx.pe.ThreadContext.getCachedStatement(ThreadContext.java:734)
        at com.xxx.pe.ThreadContext.getCachedStatement(ThreadContext.java:755)
        at com.xxx.json.AAsset.loadFromDB(AAsset.java:333)