问题描述

在做java导出Excel数据的时候，接口层面需要有HttpServletResponse的入参来设置输出流

然后执行的时候报getOutputStream() has already been called for this response错误

问题排查

返回的错误信息

{
    "timestamp": "2024-04-16T11:49:54.900+00:00",
    "status": 500,
    "error": "Internal Server Error",
    "message": "getOutputStream() has already been called for this response",
    "path": "/export/exportData"
}

查询错误日志

java.lang.IllegalStateException: getOutputStream() has already been called for this response
	at org.apache.catalina.connector.Response.getWriter(Response.java:586)
	at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:225)
	at com.alibaba.fastjson.serializer.ASMSerializer_5_ResponseFacade.write(Unknown Source)
	at com.alibaba.fastjson.serializer.JSONSerializer.write(JSONSerializer.java:312)
	at com.alibaba.fastjson.JSON.toJSONString(JSON.java:793)
	at com.alibaba.fastjson.JSON.toJSONString(JSON.java:731)
	at com.alibaba.fastjson.JSON.toJSONString(JSON.java:688)
	at com.XXX.open.record.aspect.ServiceAspect.before(ServiceAspect.java:54)
	at sun.reflect.GeneratedMethodAccessor296.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:626)
	at org.springframework.aop.aspectj.AspectJMethodBeforeAdvice.before(AspectJMethodBeforeAdvice.java:44)
	at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:55)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
	at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:88)

从错误日志可以发现是在切面ServiceAspect类的before方法报错的

点击进入报错的代码，发现此处的方式是

@Before(value = POINT_CUT)
    public void before(JoinPoint joinPoint) {
        String className = joinPoint.getTarget().getClass().getName();
        String methodName = joinPoint.getSignature().getName();
        StringBuilder logStr = new StringBuilder();
        logStr.append(className)
                .append(".")
                .append(methodName)
                .append("() , params: ");
        Object[] args = joinPoint.getArgs();
        for (Object arg : args) {
            logStr.append(JSONObject.toJSONString(arg) + ", ");//报错代码
        }
        RequestContext requestContext = RequestContext.getCurrentContext();
        requestContext.set(ConfigConstants.REQUEST_DATA, logStr.toString());
        // 通过Sleuth的Tracer获取本次请求的唯一标识，并作为logId打印
        if (null != tracer && null != tracer.currentSpan()) {
            requestContext.set(RequestParamConst.LOG_ID, tracer.currentSpan().context().traceIdString());
        } else {
            requestContext.set(RequestParamConst.LOG_ID, "");
        }

看来是json序列化HttpServletResponse参数时报错的。

解决方法

添加判断，如果入参类型是HttpServletResponse，则不序列号。问题解决

@Before(value = POINT_CUT)
    public void before(JoinPoint joinPoint) {
        String className = joinPoint.getTarget().getClass().getName();
        String methodName = joinPoint.getSignature().getName();
        StringBuilder logStr = new StringBuilder();
        logStr.append(className)
                .append(".")
                .append(methodName)
                .append("() , params: ");
        Object[] args = joinPoint.getArgs();
        for (Object arg : args) {
            if(arg instanceof HttpServletResponse){
                continue;
            }
            logStr.append(JSONObject.toJSONString(arg) + ", ");
        }
        RequestContext requestContext = RequestContext.getCurrentContext();
        requestContext.set(ConfigConstants.REQUEST_DATA, logStr.toString());
        // 通过Sleuth的Tracer获取本次请求的唯一标识，并作为logId打印
        if (null != tracer && null != tracer.currentSpan()) {
            requestContext.set(RequestParamConst.LOG_ID, tracer.currentSpan().context().traceIdString());
        } else {
            requestContext.set(RequestParamConst.LOG_ID, "");
        }
    }