Cannot get session id from managed bean

Question

I have this managed bean:

package com.DX_57.SR_57;
/** include default packages for Beans */
import java.io.Serializable;
import javax.enterprise.context.SessionScoped;
   // or import javax.faces.bean.SessionScoped;
import javax.inject.Named;
/** include package for SHA-256 encryption */
import java.security.NoSuchAlgorithmException;
/** include SQL Packages */
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.sql.DataSource;
import javax.annotation.Resource;
import javax.faces.context.FacesContext;
import javax.inject.Inject;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
   // or import javax.faces.bean.ManagedBean;   
import org.DX_57.osgi.CL_27.api.CryptoSHA;
import org.glassfish.osgicdi.OSGiService;
import org.DX_57.osgi.SH_27.api.SessionHandle;


@Named("loginController")

@SessionScoped

public class userCheck implements Serializable {
    private String user = null;
    private String password = null;  
    private String error_Message = null;
    private String error_Database = null;

       public userCheck(){
       }

       /** Call the Oracle JDBC Connection driver */
       @Resource(name="jdbc/Oracle")
       private DataSource ds;

       /** Call OSGI Bundle SH_27 SessionHandle Library */
       /** Use transient in order to disable serialization when calling OSGI Bundle */
       @Inject @OSGiService(dynamic=true) transient SessionHandle SH;

       public String OSGISHCheckUserDB(String CheckUser) throws SQLException{        
            return SH.CheckUserDB(CheckUser);
       }

       public String OSGISHSessionRegister(String User) throws SQLException{        
            return SH.SessionRegister(User);
       }

       /** Call OSGI Bundle CL_27 Crypto Library */
       /** Use transient in order to disable serialization when calling OSGI Bundle */
       @Inject @OSGiService(dynamic=true) transient CryptoSHA CL;

       public String OSGICLShaEncryptHash(String CString) throws NoSuchAlgorithmException{        
            return CL.ShaEncryptHash(CString);
       }      

       /** get the content of the variables from the JSF Login page */
       public void setUser(String newValue) { 
           user = newValue; 
       }

       public String getUser(){
           return user;       
       }

       public void setPassword(String newValue) { 
           password = newValue; 
       } 

       public String getPassword(){
           return password;
       }

       public String geterror_Database(){
           return error_Database;
       }

       public String geterror_Message(){
           return error_Message;
       }


       /** get user session id */
       FacesContext fCtx = FacesContext.getCurrentInstance();
       HttpSession session = (HttpSession) fCtx.getExternalContext().getSession(false);
       String sessionId = session.getId();             

       /** get user IP address */           
       FacesContext context = FacesContext.getCurrentInstance();
       HttpServletRequest request = (HttpServletRequest)context.getExternalContext().getRequest();
       String remoteHost = request.getRemoteAddr();



       /** compare the user and the password */
       public String userCompare() throws NoSuchAlgorithmException, SQLException { 
            String hash_passwd = null;           
            String passwdQuery = null;

            /** check the password into Oracle using the username */
            passwdQuery = OSGISHCheckUserDB(user);

            /** convert the plain password in SHA-256 hash */
//          hash_passwd = string_hash(password); 

            /** compare the encrypted passwords */
            if (password.equals(passwdQuery)){     
                /** insert into users session table the time when the user login */
//                SessionRegister(user);
                /* success */                                 
                return "0";       
            } else {  
                /* failer */ 
                return "1";              
            }            
       }   

}

I can successfully compile it with Netbeans. When I deploy it on Glassfish and I open it I get this error stack:

[#|2012-02-04T18:29:36.554+0200|INFO|glassfish3.1.1|org.glassfish.osgijavaeebase|_ThreadID=64;_ThreadName=Thread-2;|deployed bundle com.DX_57.SR_57 [296] at file:/tmp/osgiapp4499752333201324876/|#]

[#|2012-02-04T18:29:48.047+0200|SEVERE|glassfish3.1.1|javax.enterprise.resource.webcontainer.jsf.application|_ThreadID=143;_ThreadName=Thread-2;|Error Rendering View[/home.xhtml]
com.sun.faces.mgbean.ManagedBeanCreationException: Cant instantiate class: com.DX_57.SR_57.userCheck.
    at com.sun.faces.mgbean.BeanBuilder.newBeanInstance(BeanBuilder.java:193)
    at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:102)
    at com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:409)
    at com.sun.faces.mgbean.BeanManager.create(BeanManager.java:269)
    at com.sun.faces.el.ManagedBeanELResolver.resolveBean(ManagedBeanELResolver.java:244)
    at com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:116)
    at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
    at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
    at com.sun.el.parser.AstIdentifier.getValue(AstIdentifier.java:99)
    at com.sun.el.parser.AstValue.getValue(AstValue.java:158)
    at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:219)
    at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
    at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)
    at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182)
    at javax.faces.component.UIOutput.getValue(UIOutput.java:169)
    at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getValue(HtmlBasicInputRenderer.java:205)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getCurrentValue(HtmlBasicRenderer.java:355)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeEnd(HtmlBasicRenderer.java:164)
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1763)
    at javax.faces.render.Renderer.encodeChildren(Renderer.java:168)
    at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1756)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1759)
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:401)
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:594)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1539)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:98)
    at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:91)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:162)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:330)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:174)
    at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:828)
    at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:725)
    at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1019)
    at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:225)
    at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
    at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
    at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
    at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
    at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
    at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
    at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
    at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.NullPointerException
    at com.DX_57.SR_57.userCheck.<init>(userCheck.java:103)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
    at java.lang.Class.newInstance0(Class.java:372)
    at java.lang.Class.newInstance(Class.java:325)
    at com.sun.faces.mgbean.BeanBuilder.newBeanInstance(BeanBuilder.java:188)
    ... 54 more
|#]

The problem is in these lines:

 /** get user session id */
       FacesContext fCtx = FacesContext.getCurrentInstance();
       HttpSession session = (HttpSession) fCtx.getExternalContext().getSession(false);
       String sessionId = session.getId();

Can you give me some advice how to fix them?

Answer 1

The culprit is here:

...getExternalContext().getSession(false);

Read the javadoc what the boolean argument does.

If the create parameter is true , create (if necessary) and return a session instance associated with the current request. If the create parameter is false return any existing session instance associated with the current request, or return null if there is no such session .