EasyExcel缺少字体导出报错

问题描述：使用easyexcel导出数据，开发、测试环境能正常导出，在生产导出时数据为空。代码FontConfiguration.getVersion处报空指针。

报错信息：

java.lang.InternalError: java.lang.reflect.InvocationTargetException
com.alibaba.excel.exception.ExcelGenerateException: java.lang.InternalError: java.lang.reflect.InvocationTargetException
        at com.alibaba.excel.write.ExcelBuilderImpl.addContent(ExcelBuilderImpl.java:64)
        at com.alibaba.excel.ExcelWriter.write(ExcelWriter.java:161)
        at com.alibaba.excel.ExcelWriter.write(ExcelWriter.java:146)
        at com.alibaba.excel.write.builder.ExcelWriterSheetBuilder.doWrite(ExcelWriterSheetBuilder.java:61)
        at com.xxx.xxx.utils.ExcelUtil.writeExcel(ExcelUtil.java:54)
        at com.xxx.xxx.utils.ExcelUtil.writeExcel(ExcelUtil.java:27)
        at com.xxx.xxx.service.SlaInstanseSrv.exportData(SlaInstanseSrv.java:423)
        at com.xxx.xxx.control.SlaInstanseController.exportData(SlaInstanseController.java:44)
        at com.xxx.xxx.control.SlaInstanseController$$FastClassBySpringCGLIB$$5c1d4c50.invoke()
        at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:771)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749)
        at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:88)
        at com.xxx.web.common.aop.LoggingAspect.logAround(LoggingAspect.java:36)
        at jdk.internal.reflect.GeneratedMethodAccessor210.invoke(Unknown Source)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:566)
        at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:644)
        at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:633)
        at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:70)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749)
        at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:95)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749)
        at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:691)
        at com.xxx.xxx.control.SlaInstanseController$$EnhancerBySpringCGLIB$$d3b1a689.exportData()
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:566)
        at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190)
        at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
        at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:878)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:792)
        at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
        at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:645)
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:750)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:888)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1597)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.InternalError: java.lang.reflect.InvocationTargetException
        at java.desktop/sun.font.FontManagerFactory$1.run(FontManagerFactory.java:86)
        at java.base/java.security.AccessController.doPrivileged(Native Method)
        at java.desktop/sun.font.FontManagerFactory.getInstance(FontManagerFactory.java:74)
        at java.desktop/java.awt.Font.getFont2D(Font.java:497)
        at java.desktop/java.awt.Font.canDisplayUpTo(Font.java:2246)
        at java.desktop/java.awt.font.TextLayout.singleFont(TextLayout.java:469)
        at java.desktop/java.awt.font.TextLayout.(TextLayout.java:530)
        at org.apache.poi.ss.util.SheetUtil.getDefaultCharWidth(SheetUtil.java:275)
        at org.apache.poi.xssf.streaming.AutoSizeColumnTracker.(AutoSizeColumnTracker.java:117)
        at org.apache.poi.xssf.streaming.SXSSFSheet.(SXSSFSheet.java:82)
        at org.apache.poi.xssf.streaming.SXSSFWorkbook.createAndRegisterSXSSFSheet(SXSSFWorkbook.java:658)
        at org.apache.poi.xssf.streaming.SXSSFWorkbook.createSheet(SXSSFWorkbook.java:679)
        at org.apache.poi.xssf.streaming.SXSSFWorkbook.createSheet(SXSSFWorkbook.java:90)
        at com.alibaba.excel.util.WorkBookUtil.createSheet(WorkBookUtil.java:66)
        at com.alibaba.excel.context.WriteContextImpl.createSheet(WriteContextImpl.java:205)
        at com.alibaba.excel.context.WriteContextImpl.initSheet(WriteContextImpl.java:185)
        at com.alibaba.excel.context.WriteContextImpl.currentSheet(WriteContextImpl.java:122)
        at com.alibaba.excel.write.ExcelBuilderImpl.addContent(ExcelBuilderImpl.java:53)
        ... 77 common frames omitted
Caused by: java.lang.reflect.InvocationTargetException: null
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)
        at java.desktop/sun.font.FontManagerFactory$1.run(FontManagerFactory.java:84)
        ... 94 common frames omitted
Caused by: java.lang.NullPointerException: null
        at java.desktop/sun.awt.FontConfiguration.getVersion(FontConfiguration.java:1262)
        at java.desktop/sun.awt.FontConfiguration.readFontConfigFile(FontConfiguration.java:225)
        at java.desktop/sun.awt.FontConfiguration.init(FontConfiguration.java:107)
        at java.desktop/sun.awt.X11FontManager.createFontConfiguration(X11FontManager.java:719)
        at java.desktop/sun.font.SunFontManager$2.run(SunFontManager.java:367)
        at java.base/java.security.AccessController.doPrivileged(Native Method)
        at java.desktop/sun.font.SunFontManager.(SunFontManager.java:312)
        at java.desktop/sun.awt.FcFontManager.(FcFontManager.java:35)
        at java.desktop/sun.awt.X11FontManager.(X11FontManager.java:56)
        ... 99 common frames omitted

错误原因：linux主机上不存在一个字体（使用fc-list命令来查看是否存在字体）。

开发环境问题重现：

1.编辑 /etc/fonts/fonts.conf文件，注释掉字体目录

2. :wq保存退出，执行fc-cache命令刷新字体（fc-list命令能查看到字体），然后重启服务

此时导出excel时报错，如果再放开/etc/fonts/fonts.conf中的注释，fc-cache后重启服务，则正常。

实际测试只有fc-list命令能随便看到一种字体，则可以正常导出excel。

解决方法：从正常的机器上拷贝一个字体到/etc/fonts/fonts.conf中指定的目录下，然后fc-cache后重启服务，则能正常导出excel