VelocityViewServlet : Error processing the template

Invocation of method 'getRequestURLfromAtt' in  class tenders.util.VelocityTools threw exception java.lang.NullPointerException at /WEB-INF/templates/template/header.vm[line 37, column 105]
org.apache.velocity.exception.MethodInvocationException: Invocation of method 'getRequestURLfromAtt' in class tenders.util.VelocityTools threw exception java.lang.NullPointerException at /WEB-INF/templates/template/header.vm[line 37, column 105] at org.apache.velocity.runtime.parser.node.ASTMethod.handleInvocationException(ASTMethod.java:243) at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:187) at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:280) at org.apache.velocity.runtime.parser.node.ASTReference.render(ASTReference.java:369) at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:342) at org.apache.velocity.runtime.parser.node.ASTStringLiteral.value(ASTStringLiteral.java:330) at org.apache.velocity.runtime.parser.node.ASTExpression.value(ASTExpression.java:71) at org.apache.velocity.runtime.parser.node.ASTSetDirective.render(ASTSetDirective.java:142) at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:342) at org.apache.velocity.runtime.directive.Parse.render(Parse.java:260) at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:207) at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:342) at org.apache.velocity.Template.merge(Template.java:356) at org.apache.velocity.Template.merge(Template.java:260) at org.apache.velocity.tools.view.servlet.VelocityLayoutServlet.mergeTemplate(VelocityLayoutServlet.java:253) at org.apache.velocity.tools.view.servlet.VelocityViewServlet.doRequest(VelocityViewServlet.java:434) at org.apache.velocity.tools.view.servlet.VelocityViewServlet.doGet(VelocityViewServlet.java:392) at javax.servlet.http.HttpServlet.service(HttpServlet.java:624) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2517) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2506) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Unknown Source) Caused by: java.lang.NullPointerException at tenders.util.VelocityTools.getRequestURLfromAtt(VelocityTools.java:73) at sun.reflect.GeneratedMethodAccessor78.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.doInvoke(UberspectImpl.java:395) at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:384) at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:173) ... 38 more