java - 使用bodyhandler上传Java vertx 3.2文件

java.lang.IllegalStateException：在vertx3.0中，请求已被读取为异常。我尝试了很多方法。简单的formupload工作正常。但是，当我使用主体处理程序时，它会抛出以下异常。有人可以帮忙吗？

import io.vertx.core.AbstractVerticle;
import io.vertx.core.http.HttpHeaders;

import io.vertx.ext.web.Router;
import io.vertx.ext.web.handler.BodyHandler;

/*
 * @author Gogs
 */

public class TestServer extends AbstractVerticle {

  // Convenience method so you can run it in your IDE
  public static void main(String[] args) {
    Runner.runExample(TestServer.class);
  }

  @Override
  public void start() throws Exception {

    Router router = Router.router(vertx);

    // Enable multipart form data parsing
    router.route().handler(BodyHandler.create());

    router.route("/").handler(routingContext -> {
      routingContext.response().putHeader("content-type", "text/html").end(
          "<form action=\"/form\" ENCTYPE=\"multipart/form-data\" method=\"POST\" name=\"wibble\">\n" +
           "choose a file to upload:<input type=\"file\" name=\"myfile\"/><br>"+
          " <input type=\"submit\"/>"+
          "</form>"
      );
    });

    // handle the form
    router.post("/form").handler(ctx -> {

      ctx.request().setExpectMultipart(true);
      ctx.request().uploadHandler(upload -> {
          upload.exceptionHandler(cause -> {
            ctx.response().setChunked(true).end("Upload failed");
          });

          upload.endHandler(v -> {
            ctx.response().setChunked(true).end("Successfully uploaded to " + upload.filename());
          });
          // FIXME - Potential security exploit! In a real system you must check this filename
          // to make sure you're not saving to a place where you don't want!
          // Or better still, just use Vert.x-Web which controls the upload area.
          upload.streamToFileSystem(upload.filename());
        });


    });

    vertx.createHttpServer().requestHandler(router::accept).listen(8090);
  }
}

Am seeing the below exception.


Feb 02, 2016 6:48:54 PM io.vertx.ext.web.impl.RoutingContextImplBase

SEVERE: Unexpected exception in route

java.lang.IllegalStateException: Request has already been read

    at io.vertx.core.http.impl.HttpServerRequestImpl.checkEnded(HttpServerRequestImpl.java:426)
    at io.vertx.core.http.impl.HttpServerRequestImpl.setExpectMultipart(HttpServerRequestImpl.java:322)
    at io.vertx.ext.web.impl.HttpServerRequestWrapper.setExpectMultipart(HttpServerRequestWrapper.java:166)
    at com.vertx.http.upload.TestServer.lambda$1(TestServer.java:43)
    at io.vertx.ext.web.impl.RouteImpl.handleContext(RouteImpl.java:221)
    at io.vertx.ext.web.impl.RoutingContextImplBase.iterateNext(RoutingContextImplBase.java:78)
    at io.vertx.ext.web.impl.RoutingContextImpl.next(RoutingContextImpl.java:93)
    at io.vertx.ext.web.handler.impl.BodyHandlerImpl$BHandler.doEnd(BodyHandlerImpl.java:155)
    at io.vertx.ext.web.handler.impl.BodyHandlerImpl$BHandler.uploadEnded(BodyHandlerImpl.java:135)
    at io.vertx.ext.web.handler.impl.BodyHandlerImpl$BHandler.lambda$null$35(BodyHandlerImpl.java:109)
    at io.vertx.core.http.impl.HttpServerFileUploadImpl.notifyEndHandler(HttpServerFileUploadImpl.java:213)
    at io.vertx.core.http.impl.HttpServerFileUploadImpl.lambda$handleComplete$165(HttpServerFileUploadImpl.java:206)
    at io.vertx.core.file.impl.AsyncFileImpl.lambda$doClose$226(AsyncFileImpl.java:470)
    at io.vertx.core.impl.ContextImpl.lambda$wrapTask$16(ContextImpl.java:335)
    at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:358)
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:357)
    at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:112)
    at java.lang.Thread.run(Unknown Source)

最佳答案

您正在阅读请求正文两次。第一次读取是通过BodyHandler（请参见BodyHanderImpl），第二次是通过您自己的处理程序（请参见HttpServerRequestImpl和HttpServerFileUploadImpl）。

BodyHandler完全从请求中读取正文，并使其在context.body中可用。路由器的配置方式：

router.route().handler(BodyHandler.create());

在路由器处理的每个单个请求中，都会完整读取正文。

您的处理程序还正在完全读取请求正文并将其内容写入文件系统。将路由器配置为仅在对/form进行POST时执行处理程序。

概括一下流程，当您将上载提交到/form BodyHandler时，它是在完全读取请求，将内容存储在context.body中，并将请求正文标记为已读。您的路由器将uri路径与您的上传处理程序匹配，并尝试再次读取正文，但由于已经读取了正文，因此引发了异常。

一些想法...

如果您打算将上传的文件写入文件系统，则实际上不需要在路由器中配置BodyHandler。您需要在内存中需要主体以某种方式进行处理时，使用BodyHandler。除非打算对路由器收到的单个请求执行处理程序，否则不应配置没有匹配条件（即router.route().handler(...)）的处理程序。此类处理程序的一个很好的用例是CookieHandler。