Question

我在Spring 4.2.0.BUILD-SNAPSHOT中使用了新增的HTTP Streaming功能和ResponseBodyEmitter。

我想在（可能是java）客户端和服务器之间的不可用数据流上实现长时间运行的持久TCP连接，直到客户端断开连接。我想避免使用websocket协议。

如果客户端在流式传输时断开连接，则抛出运行时IllegalStateException。我想优雅地处理这个并清理发射器。没有捕获运行时异常，有没有办法优雅地处理它？</ li>
我必须在发射器上为＆＃34; persistent＆＃34;指定一个人为高的超时值。连接。我可以设置暂停吗？

webapp部署在apache-tomcat-7.0.62上。

相关代码如下：

    while (true) {
        for (Iterator<ResponseBodyEmitter> iterator = emitters.iterator(); iterator.hasNext();) {
            ResponseBodyEmitter emitter = iterator.next();
            try {
                emitter.send("data...", MediaType.TEXT_PLAIN);
            } catch (IOException | IllegalStateException e) {
                LOGGER.error(e);
                iterator.remove();
            }
        }

        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            LOGGER.error(e);
        }
    }

INFO: An error occurred in processing while on a non-container thread. The connection will be closed immediately
java.net.SocketException: Broken pipe
    at java.net.SocketOutputStream.socketWrite0(Native Method)
    at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:109)
    at java.net.SocketOutputStream.write(SocketOutputStream.java:153)
    at org.apache.coyote.http11.InternalOutputBuffer.realWriteBytes(InternalOutputBuffer.java:215)
    at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:480)
    at org.apache.coyote.http11.InternalOutputBuffer.flush(InternalOutputBuffer.java:119)
    at org.apache.coyote.http11.AbstractHttp11Processor.action(AbstractHttp11Processor.java:801)
    at org.apache.coyote.Response.action(Response.java:172)
    at org.apache.catalina.connector.OutputBuffer.doFlush(OutputBuffer.java:363)
    at org.apache.catalina.connector.OutputBuffer.flush(OutputBuffer.java:331)
    at org.apache.catalina.connector.CoyoteOutputStream.flush(CoyoteOutputStream.java:101)
    at sun.nio.cs.StreamEncoder.implFlush(StreamEncoder.java:297)
    at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:141)
    at java.io.OutputStreamWriter.flush(OutputStreamWriter.java:229)
    at org.springframework.util.StreamUtils.copy(StreamUtils.java:106)
    at org.springframework.http.converter.StringHttpMessageConverter.writeInternal(StringHttpMessageConverter.java:109)
    at org.springframework.http.converter.StringHttpMessageConverter.writeInternal(StringHttpMessageConverter.java:40)
    at org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:193)
    at org.springframework.web.servlet.mvc.method.annotation.ResponseBodyEmitterReturnValueHandler$HttpMessageConvertingHandler.sendInternal(ResponseBodyEmitterReturnValueHandler.java:157)
    at org.springframework.web.servlet.mvc.method.annotation.ResponseBodyEmitterReturnValueHandler$HttpMessageConvertingHandler.send(ResponseBodyEmitterReturnValueHandler.java:150)
    at org.springframework.web.servlet.mvc.method.annotation.ResponseBodyEmitter.sendInternal(ResponseBodyEmitter.java:180)
    at org.springframework.web.servlet.mvc.method.annotation.ResponseBodyEmitter.send(ResponseBodyEmitter.java:164)
    ....

[ERROR] [02/07/15 18:11 PM] [Controller$TestResponseBodyEmitter:74] - java.lang.IllegalStateException: The request associated with the AsyncContext has already completed processing.

日志：

curl http://localhost:8080/myapp/stream -v -N
data...data...
Ctrl-C

命令：

NewObject

Answer 1

根据ResponseBodyEmitter的构造函数的Javadoc（找到here）。

使用自定义超时值创建ResponseBodyEmitter。默认情况下不设置在MVC Java Config中配置的默认值使用MVC命名空间，或者如果未设置，则超时取决于底层服务器的默认值。

因此，在创建c实例时，会发出超时。

PS：在我的环境中，ResponseBodyEmitter＃getTimeout（）返回null;这并不意味着存在无限超时。相反，5-10秒后连接超时。

在Spring-MVC中使用ResponseBodyEmitter进行HTTP Streaming时出现IllegalStateException

1 个答案: