使用bodyhandler上传Java vertx 3.2文件

Question

java.lang.IllegalStateException: Request has already been read exception in vertx3.0. I tried in many ways. The simple formupload is working fine. But when i use body handler, it is throwing below exception. Can anybody help ?

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)

Answer 1

You are reading the request body twice. The first read is via BodyHandler (see BodyHanderImpl ) and the second is by your own handler (see HttpServerRequestImpl and HttpServerFileUploadImpl ).

BodyHandler reads the body from the request fully and makes it available in context.body . The way your router is configured:

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

the body will be read completely on every single request handled by your router.

Your handler is also reading the request body fully and writing its contents to the file system. Your router is configured to only execute your handler when a POST is made to /form .

To recap the flow, when you submit the upload to /form BodyHandler is reading the request fully, storing the contents in context.body, and marking the request body as read. Your router matches the uri path to your upload handler and attempts to read the body again but since it has already been read the exception is raised.

Some thoughts...

If your intent is to write the uploaded file to the file system you really don't need BodyHandler configured in your router. You would want to use BodyHandler when you needed the body in memory in order to process it in some way. Unless you intend to execute a handler on very single request received by your router, you should not configure a handler without matching criteria (ie router.route().handler(...) ). A good use case for this type of handler is CookieHandler.

Answer 2

http://grepcode.com/file/repo1.maven.org/maven2/io.vertx/vertx-web/3.0.0/io/vertx/ext/web/impl/RouterImpl.java#RouterImpl

Gogs, I was looking at this code, and quite possible we could implement our own Router or something similar that could then be managed in the accept method...

Answer 3

我们可能可以创建自己的bodyhandler ...在配置文件中提供被忽略路由的列表： http ://grepcode.com/file/repo1.maven.org/maven2/io.vertx/vertx-web/3.0.0 /io/vertx/ext/web/handler/impl/BodyHandlerImpl.java#BodyHandlerImpl