Sorry, this is the complete stacktrace of my error:

com.ibm.xsp.extlib.jdbc.datasource.xpages.JdbcPoolDataSource.getConnection(JdbcPoolDataSource.java:53)
com.ibm.xsp.extlib.jdbc.jndi.JndiDataSourceProxy.getConnection(JndiDataSourceProxy.java:128)
com.ibm.xsp.extlib.util.JdbcUtil.createNamedConnection(JdbcUtil.java:84)
com.ibm.xsp.extlib.util.JdbcUtil.getConnection(JdbcUtil.java:68)
com.sipjn.DB2DAO.crearConexion(DB2DAO.java:30)
com.sipjn.DB2DAO.recuperar(DB2DAO.java:47)
com.sipjn.ncpp.dao.LegajoDAO.recuperarLegajos(LegajoDAO.java:37)
com.sipjn.ncpp.dao.facade.LegajoCRUDFacade.recuperarLegajos(LegajoCRUDFacade.java:26)
com.sipjn.ncpp.bean.LegajoBean.cargarLegajos(LegajoBean.java:38)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:60)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
java.lang.reflect.Method.invoke(Method.java:611)
com.ibm.jscript.types.JavaAccessObject.call(JavaAccessObject.java:321)
com.ibm.jscript.types.FBSObject.call(FBSObject.java:161)
com.ibm.jscript.ASTTree.ASTCall.interpret(ASTCall.java:175)
com.ibm.jscript.ASTTree.ASTProgram.interpret(ASTProgram.java:119)
com.ibm.jscript.ASTTree.ASTProgram.interpretEx(ASTProgram.java:139)
com.ibm.jscript.JSExpression._interpretExpression(JSExpression.java:435)
com.ibm.jscript.JSExpression.access$1(JSExpression.java:424)
com.ibm.jscript.JSExpression$2.run(JSExpression.java:414)
java.security.AccessController.doPrivileged(AccessController.java:284)
com.ibm.jscript.JSExpression.interpretExpression(JSExpression.java:410)
com.ibm.jscript.JSExpression.evaluateValue(JSExpression.java:251)
com.ibm.jscript.JSExpression.evaluateValue(JSExpression.java:234)
com.ibm.xsp.javascript.JavaScriptInterpreter.interpret(JavaScriptInterpreter.java:221)
com.ibm.xsp.binding.javascript.JavaScriptMethodBinding.invoke(JavaScriptMethodBinding.java:111)
com.ibm.xsp.component.UIViewRootEx.initAfterContents(UIViewRootEx.java:1690)
com.ibm.xsp.page.compiled.AbstractCompiledPage.initComponent(AbstractCompiledPage.java:335)
com.ibm.xsp.page.compiled.AbstractCompiledPage.createTree(AbstractCompiledPage.java:256)
com.ibm.xsp.page.compiled.AbstractCompiledPage.createViewRoot(AbstractCompiledPage.java:167)
com.ibm.xsp.application.ViewHandlerExImpl._createViewRoot(ViewHandlerExImpl.java:511)
com.ibm.xsp.application.ViewHandlerExImpl.createViewRoot(ViewHandlerExImpl.java:557)
com.ibm.xsp.application.ViewHandlerExImpl.doCreateView(ViewHandlerExImpl.java:141)
com.ibm.xsp.application.ViewHandlerEx.createView(ViewHandlerEx.java:90)
com.ibm.xsp.webapp.FacesServlet.serviceView(FacesServlet.java:238)
com.ibm.xsp.webapp.FacesServletEx.serviceView(FacesServletEx.java:204)
com.ibm.xsp.webapp.FacesServlet.service(FacesServlet.java:160)
com.ibm.xsp.webapp.FacesServletEx.service(FacesServletEx.java:138)
com.ibm.xsp.webapp.DesignerFacesServlet.service(DesignerFacesServlet.java:103)
com.ibm.designer.runtime.domino.adapter.ComponentModule.invokeServlet(ComponentModule.java:583)
com.ibm.domino.xsp.module.nsf.NSFComponentModule.invokeServlet(NSFComponentModule.java:1281)
com.ibm.designer.runtime.domino.adapter.ComponentModule$AdapterInvoker.invokeServlet(ComponentModule.java:854)
com.ibm.designer.runtime.domino.adapter.ComponentModule$ServletInvoker.doService(ComponentModule.java:803)
com.ibm.designer.runtime.domino.adapter.ComponentModule.doService(ComponentModule.java:572)
com.ibm.domino.xsp.module.nsf.NSFComponentModule.doService(NSFComponentModule.java:1265)
com.ibm.domino.xsp.module.nsf.NSFService.doServiceInternal(NSFService.java:658)
com.ibm.domino.xsp.module.nsf.NSFService.doService(NSFService.java:481)
com.ibm.designer.runtime.domino.adapter.LCDEnvironment.doService(LCDEnvironment.java:341)
com.ibm.designer.runtime.domino.adapter.LCDEnvironment.service(LCDEnvironment.java:297)
com.ibm.domino.xsp.bridge.http.engine.XspCmdManager.service(XspCmdManager.java:272)