2
votes

I use weblogic application server and oracle database. I use jdbc for communicating with the oracle database. I get the connection from weblogic datasource and insert a record to the table. The problem is that when I want to close the connection (after inserting to the database) I'll face with an exception (Connection has already been closed) .This is my code:

private Connection getConnection() {
    try {
        Context context = new InitialContext();
        DataSource datasource = (DataSource) context.lookup("jdbc/datasource-uat");
        Connection connection = datasource.getConnection();
        connection.setAutoCommit(false);
        return connection;
    } catch (Throwable throwable) {
        throwable.printStackTrace();
        return null;
    }
}


    public void persist(Long id) {
    Connection connection = null;
    try {
        connection = getConnection();
        PreparedStatement preparedStatement;
        ResultSet resultSet = null;
        if (id == 0L) {
            synchronized (this) {
                preparedStatement = connection.prepareStatement("SELECT MY_BEAN_SEQ.NEXTVAL FROM DUAL");
                resultSet = preparedStatement.executeQuery();
            }
            resultSet.next();
            id = resultSet.getLong("NEXTVAL");
        }

        preparedStatement = connection.prepareStatement("INSERT INTO MY_BEAN (ID) VALUES (?)");
        preparedStatement.setLong(1, id);
        preparedStatement.executeUpdate();
        connection.commit();
        if (resultSet != null) {
            resultSet.close();
        }
        preparedStatement.close();


    } catch (Throwable throwable) {
        throwable.printStackTrace();
    }

    finally {
        closeConnection(connection);
    }
}


private void closeConnection(Connection connection) {
    if (connection != null)
        try {
            connection.close();
        } catch (Throwable throwable) {
            throwable.printStackTrace();
        }
}

But connection.close statement throws an exception:

java.sql.SQLException: Connection has already been closed.
at weblogic.jdbc.wrapper.PoolConnection.checkConnection(PoolConnection.java:62)
at weblogic.jdbc.wrapper.Connection.preInvocationHandler(Connection.java:100)
at weblogic.jdbc.wrapper.Connection.getMetaData(Connection.java:476)
at com.DataAccess.closeConnection(DataAccess.java:61)
at com.DataAccess.persist(DataAccess.java:289)
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.apache.cxf.service.invoker.AbstractInvoker.performInvocation(AbstractInvoker.java:188)
at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:104)
at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:204)
at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:101)
at org.apache.cxf.interceptor.ServiceInvokerInterceptor$1.run(ServiceInvokerInterceptor.java:58)
at org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:94)
at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:272)
at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121)
at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:249)
at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:248)
at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:222)
at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:153)
at org.apache.cxf.transport.servlet.CXFNonSpringServlet.invoke(CXFNonSpringServlet.java:181)
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.handleRequest(AbstractHTTPServlet.java:289)
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.doPost(AbstractHTTPServlet.java:209)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.service(AbstractHTTPServlet.java:265)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:301)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:184)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3732)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3696)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2273)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2179)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1490)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:256)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:221)

I tried to avoid connection.close statement (because I taught that connection is closed automatically!! but after a while all of the connections were opened and an exception was thrown due to that)

2
SO is full of questions covering this error message? Did you do any research before posting?Tim Biegeleisen
@Tim Biegeleisen: Did you just remove your answer? Anyway, in my case I haven't any idea what is reason of this exception. Do you have?Mohammad
add a check into closeConnection method if the connection is also still open, something like if (connection != null && connection.isOpen()) (I don't remember the exact syntax)Leviand
@Leviand Scroll down in his code. He is already doing this.Tim Biegeleisen
@TimBiegeleisen no man, he's only checking if is != nullLeviand

2 Answers

1
votes

Try using a try-with-resources Statement to "automatically" close your connection.

Similar to this

0
votes

Check out PreparedStatement sample for reference.