一直用的好好的，改了下代码，但并没有动PDF模板，就报错了

PDF header signature not found.
	at com.itextpdf.text.pdf.PRTokeniser.getHeaderOffset(PRTokeniser.java:208)
	at com.itextpdf.text.pdf.PdfReader.getOffsetTokeniser(PdfReader.java:421)
	at com.itextpdf.text.pdf.PdfReader.<init>(PdfReader.java:182)
	at com.itextpdf.text.pdf.PdfReader.<init>(PdfReader.java:249)
	at com.itextpdf.text.pdf.PdfReader.<init>(PdfReader.java:240)
	at com.juyo.visa.admin.autofill.util.TemplateUtil.mergePdf(TemplateUtil.java:167)
	at com.juyo.visa.admin.autofill.service.NewAutofillService.generateConfirmFile(NewAutofillService.java:8233)
	at com.juyo.visa.admin.autofill.service.NewAutofillService.downloadConfirmPage(NewAutofillService.java:7979)
	at com.juyo.visa.admin.autofill.service.NewAutofillService.downloadPDF(NewAutofillService.java:7949)
	at com.juyo.visa.admin.autofill.module.NewAutofillModule.downloadPDF(NewAutofillModule.java:214)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.nutz.mvc.impl.processor.MethodInvokeProcessor.process(MethodInvokeProcessor.java:25)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at com.uxuexi.core.web.chain.ValidProcessor.process(ValidProcessor.java:79)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at com.uxuexi.core.web.chain.SqlInjectProcessor.process(SqlInjectProcessor.java:69)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at org.nutz.mvc.impl.processor.AdaptorProcessor.process(AdaptorProcessor.java:33)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at org.nutz.mvc.impl.processor.ActionFiltersProcessor.process(ActionFiltersProcessor.java:58)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at org.nutz.mvc.impl.processor.ModuleProcessor.process(ModuleProcessor.java:123)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at org.nutz.mvc.impl.processor.EncodingProcessor.process(EncodingProcessor.java:27)
	at org.nutz.mvc.impl.NutActionChain.doChain(NutActionChain.java:44)
	at org.nutz.mvc.impl.ActionInvoker.invoke(ActionInvoker.java:67)
	at org.nutz.mvc.ActionHandler.handle(ActionHandler.java:31)
	at org.nutz.mvc.NutFilter.doFilter(NutFilter.java:198)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at com.uxuexi.core.web.filter.EncodingFilter.doFilter(EncodingFilter.java:36)
	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.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:436)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:745)