一直在做公司的支付中心，因為公司的業務比較多，也比較雜，有的業務是PHP寫的有的是Java。
在一次新業務對接在支付中心的時候，用restTemplate調接口時報了一個錯誤：Could not extract response: no suitable HttpMessageConverter found for response type xxxxx and content type [text/html]。
第一反應是他們那邊沒返回Json格式。
於是邊去找PHP那邊溝通，他們說他們設置了返回Json格式。我一看的確是設置了，為了兼容各種格式，於是我加了一下轉換代碼：
MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter = new MappingJackson2HttpMessageConverter(); mappingJackson2HttpMessageConverter.setSupportedMediaTypes(Arrays.asList(MediaType.APPLICATION_JSON, MediaType.TEXT_HTML)); restTemplate.getMessageConverters().add(mappingJackson2HttpMessageConverter);
測試了下，完美解決，於是開開心心上線了，結果沒過多久線上支付出現了問題，
java.util.ConcurrentModificationException: null at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1388) at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481) at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471) at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708) at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499) at org.springframework.web.client.RestTemplate$AcceptHeaderRequestCallback.doWithRequest(RestTemplate.java:851) at org.springframework.web.client.RestTemplate$HttpEntityRequestCallback.doWithRequest(RestTemplate.java:911) at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:733) at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:670) at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:608) at com.lingzhi.retail.payment.api.service.order.impl.PayOrderInfoServiceImpl.getOrderInfo(PayOrderInfoServiceImpl.java:111) at com.lingzhi.retail.payment.api.service.order.impl.PayOrderInfoServiceImpl.buildPayOrderInfo(PayOrderInfoServiceImpl.java:73) at com.lingzhi.retail.payment.route.service.impl.RoutePaymentBusinessServiceImpl.pay(RoutePaymentBusinessServiceImpl.java:58) at com.lingzhi.retail.payment.route.controller.RouteController.route(RouteController.java:58) at com.lingzhi.retail.payment.route.controller.RouteController$$FastClassBySpringCGLIB$$dcb2f075.invoke(<generated>) at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:750) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:88) at com.alibaba.csp.sentinel.annotation.aspectj.SentinelResourceAspect.invokeResourceWithSentinel(SentinelResourceAspect.java:57) at sun.reflect.GeneratedMethodAccessor106.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) 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:175) at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:88) at com.lingzhi.dubhe.log.DubheRestParamsAspect.execute(DubheRestParamsAspect.java:118) at sun.reflect.GeneratedMethodAccessor93.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) 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:175) at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:56) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:175) at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689) at com.lingzhi.retail.payment.route.controller.RouteController$$EnhancerBySpringCGLIB$$a3feecfc.route(<generated>) at sun.reflect.GeneratedMethodAccessor105.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) 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:893) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:798) 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.doPost(FrameworkServlet.java:909) at javax.servlet.http.HttpServlet.service(HttpServlet.java:665) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) at javax.servlet.http.HttpServlet.service(HttpServlet.java:750) at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:74) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129) at com.alibaba.csp.sentinel.adapter.servlet.CommonFilter.doFilter(CommonFilter.java:110) at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:94) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) at com.lingzhi.dubhe.web.ServletContextInterceptor.doFilter(ServletContextInterceptor.java:41) at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) at com.lingzhi.dubhe.language.filter.LanguageResourceFilter.doFilter(LanguageResourceFilter.java:55) at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) at com.lingzhi.dubhe.web.LanguageContextFilter.doFilter(LanguageContextFilter.java:44) at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) at com.lingzhi.dubhe.service.trace.servlet.filter.ServiceTraceServletFilter.doFilter(ServiceTraceServletFilter.java:41) at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) at com.lingzhi.dubhe.security.filter.RequestResponseSecurityFilter.doFilter(RequestResponseSecurityFilter.java:45) at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) at com.lingzhi.dubhe.log.trace.servlet.LogTraceServletFilter.doFilter(LogTraceServletFilter.java:43) at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84) at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62) at io.undertow.servlet.handlers.ServletChain$1.handleRequest(ServletChain.java:68) at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36) at io.undertow.servlet.handlers.RedirectDirHandler.handleRequest(RedirectDirHandler.java:68) at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:132) at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46) at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64) at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60) at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77) at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:269) at io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:78) at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:133) at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:130) at io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48) at io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43) at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:249) at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:78) at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:99) at io.undertow.server.Connectors.executeRootHandler(Connectors.java:376) at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:830) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748)
認真排查發現原來是自己代碼有問題，因為我是通過@Autowired注入的restTemplate，然后每次都會執行restTemplate.getMessageConverters().add(mappingJackson2HttpMessageConverter);
restTemplate.getMessageConverters是個list,然后就是沒調一次都會addmappingJackson2HttpMessageConverter。
然后因為我們的一天支付量還挺多的，一下就內存滿了。
問題找到，那就得解決
1、不通過@Autowired注入，每次都new restTemplate();
2、通過@Autowired注入，但是 類實現InitializingBean 接口，在 afterPropertiesSet方法里面去add一次就好了，不需要每次都設置
3、通過@PostConstruct注解完成2中的的功能。
總之解決思路就是 只執行一次restTemplate.getMessageConverters().add(mappingJackson2HttpMessageConverter);就好了。