java.lang.NullPointerException at com.mysteel.site.album.web.tag.AlbumTag.getPhotoById(AlbumTag.java:42) at sun.reflect.GeneratedMethodAccessor247.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.doInvoke(UberspectImpl.java:571) at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:554) at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:221) at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:368) at org.apache.velocity.runtime.parser.node.ASTReference.value(ASTReference.java:704) at org.apache.velocity.runtime.parser.node.ASTExpression.value(ASTExpression.java:75) at org.apache.velocity.runtime.parser.node.ASTSetDirective.render(ASTSetDirective.java:242) at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:439) at org.apache.velocity.Template.merge(Template.java:358) at org.apache.velocity.Template.merge(Template.java:262) at org.apache.velocity.tools.view.VelocityView.performMerge(VelocityView.java:854) at org.apache.velocity.tools.view.VelocityView.merge(VelocityView.java:814) at org.apache.velocity.tools.view.VelocityViewServlet.mergeTemplate(VelocityViewServlet.java:386) at org.apache.velocity.tools.view.VelocityViewServlet.doRequest(VelocityViewServlet.java:239) at org.apache.velocity.tools.view.VelocityViewServlet.doGet(VelocityViewServlet.java:193) at javax.servlet.http.HttpServlet.service(HttpServlet.java:489) at javax.servlet.http.HttpServlet.service(HttpServlet.java:583) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:212) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:156) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:181) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:156) at org.apache.logging.log4j.web.Log4jServletFilter.doFilter(Log4jServletFilter.java:71) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:181) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:156) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:168) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:483) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:130) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:346) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:617) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:934) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1698) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:63) at java.lang.Thread.run(Thread.java:750)
