环境信息 （必填）

• pigx版本: 3.6.0
• 是否修改包名: 否

docker-compose部署验证码出不来 报500

描述（无法理解工单，将直接关闭）

日志、截图、回显步骤
INFO: log output type is: file
INFO: log charset is: utf-8
INFO: log base dir is: /root/logs/csp/
INFO: log name use pid is: false
2020-04-07 16:17:43.559 ERROR 1 --- [or-http-epoll-4] a.w.r.e.AbstractErrorWebExceptionHandler : [5424d3d3] 500 Server Error for HTTP GET "/code?randomStr=59821586247463451"

java.lang.NullPointerException: null
at com.wf.captcha.base.ArithmeticCaptchaAbstract.alphas(ArithmeticCaptchaAbstract.java:42) ~[easy-captcha-1.6.2.jar!/:na]
Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException:
Error has been observed at the following site(s):
|_ checkpoint ? org.springframework.cloud.gateway.filter.WeightCalculatorWebFilter [DefaultWebFilterChain]
|_ checkpoint ? com.alibaba.csp.sentinel.adapter.spring.webflux.SentinelWebFluxFilter [DefaultWebFilterChain]
|_ checkpoint ? org.springframework.boot.actuate.metrics.web.reactive.server.MetricsWebFilter [DefaultWebFilterChain]
|_ checkpoint ? HTTP GET "/code?randomStr=59821586247463451" [ExceptionHandlingWebHandler]
Stack trace:
at com.wf.captcha.base.ArithmeticCaptchaAbstract.alphas(ArithmeticCaptchaAbstract.java:42) ~[easy-captcha-1.6.2.jar!/:na]
at com.wf.captcha.base.Captcha.checkAlpha(Captcha.java:156) ~[easy-captcha-1.6.2.jar!/:na]
at com.wf.captcha.base.Captcha.text(Captcha.java:137) ~[easy-captcha-1.6.2.jar!/:na]
at com.pig4cloud.pigx.gateway.handler.ImageCodeHandler.handle(ImageCodeHandler.java:57) ~[classes!/:na]
at org.springframework.web.reactive.function.server.support.HandlerFunctionAdapter.handle(HandlerFunctionAdapter.java:61) ~[spring-webflux-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.web.reactive.DispatcherHandler.invokeHandler(DispatcherHandler.java:161) ~[spring-webflux-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at org.springframework.web.reactive.DispatcherHandler.lambda$handle$1(DispatcherHandler.java:146) ~[spring-webflux-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:118) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.MonoNext$NextSubscriber.onNext(MonoNext.java:76) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.innerNext(FluxConcatMap.java:274) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxConcatMap$ConcatMapInner.onNext(FluxConcatMap.java:851) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxMap$MapSubscriber.onNext(FluxMap.java:114) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxPeek$PeekSubscriber.onNext(FluxPeek.java:192) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2186) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.set(Operators.java:1994) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onSubscribe(Operators.java:1868) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.MonoJust.subscribe(MonoJust.java:54) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.Mono.subscribe(Mono.java:4105) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.drain(FluxConcatMap.java:441) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.onSubscribe(FluxConcatMap.java:211) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:139) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:63) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at com.alibaba.csp.sentinel.adapter.reactor.MonoSentinelOperator.subscribe(MonoSentinelOperator.java:40) ~[sentinel-reactor-adapter-1.7.0.jar!/:na]
at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.Mono.subscribe(Mono.java:4105) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:172) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55) ~[reactor-core-3.3.1.RELEASE.jar!/:3.3.1.RELEASE]
at reactor.netty.http.server.HttpServerHandle.onStateChange(HttpServerHandle.java:64) ~[reactor-netty-0.9.2.RELEASE.jar!/:0.9.2.RELEASE]
at reactor.netty.tcp.TcpServerBind$ChildObserver.onStateChange(TcpServerBind.java:226) ~[reactor-netty-0.9.2.RELEASE.jar!/:0.9.2.RELEASE]
at reactor.netty.http.server.HttpServerOperations.onInboundNext(HttpServerOperations.java:441) ~[reactor-netty-0.9.2.RELEASE.jar!/:0.9.2.RELEASE]
at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:89) ~[reactor-netty-0.9.2.RELEASE.jar!/:0.9.2.RELEASE]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at reactor.netty.http.server.HttpTrafficHandler.channelRead(HttpTrafficHandler.java:167) ~[reactor-netty-0.9.2.RELEASE.jar!/:0.9.2.RELEASE]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:326) ~[netty-codec-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:300) ~[netty-codec-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:253) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1422) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:931) ~[netty-transport-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:792) ~[netty-transport-native-epoll-4.1.43.Final-linux-x86_64.jar!/:4.1.43.Final]
at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:502) ~[netty-transport-native-epoll-4.1.43.Final-linux-x86_64.jar!/:4.1.43.Final]
at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:407) ~[netty-transport-native-epoll-4.1.43.Final-linux-x86_64.jar!/:4.1.43.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$6.run(SingleThreadEventExecutor.java:1050) ~[netty-common-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.43.Final.jar!/:4.1.43.Final]
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.43.Final.jar!/:4.1.43.Final]
at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_202]

2020-04-07 16:31:37.047 INFO 1 --- [or-http-epoll-4] c.netflix.loadbalancer.BaseLoadBalancer : Client: aiot-basicdata-biz instantiated a LoadBalancer: DynamicServerListLoadBalancer:{NFLoadBalancer:name=aiot-basicdata-biz,current list of Servers=[],Load balancer stats=Zone stats: {},Server stats: []}ServerList:null
2020-04-07 16:31:37.071 INFO 1 --- [or-http-epoll-4] c.n.l.DynamicServerListLoadBalancer : Using serverListUpdater PollingServerListUpdater
2020-04-07 16:31:37.134 INFO 1 --- [or-http-epoll-4] c.n.l.DynamicServerListLoadBalancer : DynamicServerListLoadBalancer for client aiot-basicdata-biz initialized: DynamicServerListLoadBalancer:{NFLoadBalancer:name=aiot-basicdata-biz,current list of Servers=[172.16.152.205:5000],Load balancer stats=Zone stats: {unknown=[Zone:unknown; Instance count:1; Active connections count: 0; Circuit breaker tripped count: 0; Active connections per server: 0.0;]
},Server stats: [[Server:172.16.152.205:5000; Zone:UNKNOWN; Total Requests:0; Successive connection failure:0; Total blackout seconds:0; Last connection made:Thu Jan 01 08:00:00 CST 1970; First connection made: Thu Jan 01 08:00:00 CST 1970; Active Connections:0; total failure count in last (1000) msecs:0; average resp time:0.0; 90 percentile resp time:0.0; 95 percentile resp time:0.0; min resp time:0.0; max resp time:0.0; stddev resp time:0.0]
]}ServerList:com.alibaba.cloud.nacos.ribbon.NacosServerList@66803a15
2020-04-07 16:33:49.210 ERROR 1 --- [or-http-epoll-2] a.w.r.e.AbstractErrorWebExceptionHandler : [a78367ac] 500 Server Error for HTTP GET "/code?randomStr=37791586248429127"