java - 多线程 Java HTTP 服务器

Question

我使用 sun.net.httpServer 在我的应用程序中运行 HTTP 服务器(不要问我为什么)。

问题是它只在一个线程中处理我的请求，所以我的吞吐量是一场灾难。

我想如果我 setExecutor 到我的 httpServer 这个问题就会解决，但我开始在服务器端和客户端(SOAP-UI )。我测试了各种执行器，包括 Executors.newCachedThreadPool 、 Executors.newFixedThreadPool 、 Executors.newWorkStealingPool 、 Executors.newScheduledThreadPool没有任何运气。

正如我所说，当我 setExecutor 为 null 时，我的代码工作正常，但在此配置中，我的代码按顺序处理请求。

我不知道该怎么办。这是我的代码:

public class HTTPListener {
    private HttpServer httpServer;
    private int port = 1253;

    public void stop() {
        if (httpServer != null) {
            httpServer.stop(0);
            httpServer = null;
        }
    }
    public void startHTTPServer() {
        try {
            httpServer = HttpServer.create(new InetSocketAddress(1252), 100);
            httpServer.setExecutor(null);
            httpServer.createContext("/", new RequestHandler());
            httpServer.start();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

当我设置 Executors 时出现此错误

java.io.IOException: stream closed
    at sun.net.httpserver.FixedLengthOutputStream.write(FixedLengthOutputStream.java:68)
    at sun.net.httpserver.PlaceholderOutputStream.write(ExchangeImpl.java:444)
    at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
    at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
    at java.io.FilterOutputStream.close(FilterOutputStream.java:158)
    at com.RequestHandler.sendResponse(RequestHandler.java:61)
    at com..RequestHandler.handle(RequestHandler.java:18)
    at com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:79)
    at sun.net.httpserver.AuthFilter.doFilter(AuthFilter.java:83)
    at com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:82)
    at sun.net.httpserver.ServerImpl$Exchange$LinkHandler.handle(ServerImpl.java:675)
    at com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:79)
    at sun.net.httpserver.ServerImpl$Exchange.run(ServerImpl.java:645)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

这是我的 RequestHandler 类:

public class RequestHandler implements HttpHandler {
    private HttpExchange sender;

    @Override
    public void handle(HttpExchange httpExchange) throws IOException {
        this.sender = httpExchange;
        try {
            String request = readRequestBody();
            sendResponse(200, "Hello World !");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            this.sender.close();
        }
    }

    private String readRequestBody() throws Exception {
        try (InputStream isr = sender.getRequestBody()) {
            byte[] buffer = new byte[isr.available()];
            isr.read(buffer);
            return Arrays.toString(buffer);
        } catch (IOException ex) {
            throw new Exception(ex.getMessage());
        }
    }

    private void sendResponse(int httpResponseCode, String response) throws IOException {
        OutputStream outputStream = null;
        try {
            sender.getResponseHeaders().set("Content-Type", "text/html; charset=UTF-8");
            sender.sendResponseHeaders(httpResponseCode, response.length());
            outputStream = sender.getResponseBody();
            outputStream.write(response.getBytes());
        } finally {
            if (outputStream != null)
                outputStream.close();
        }

    }
}

我也在客户端收到此错误代码

org.apache.http.ConnectionClosedException: Premature end of Content-Length delimited message body (expected: 13; received: 0
    at org.apache.http.impl.io.ContentLengthInputStream.read(ContentLengthInputStream.java:180)
    at org.apache.http.conn.EofSensorInputStream.read(EofSensorInputStream.java:137)
    at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
    at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
    at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
    at java.io.InputStreamReader.read(InputStreamReader.java:184)
    at java.io.Reader.read(Reader.java:140)
    at org.apache.http.util.EntityUtils.toString(EntityUtils.java:247)
    at org.apache.http.util.EntityUtils.toString(EntityUtils.java:291)
    at Business.HTTPHandler.Client.send(Client.java:68)
    at main.Main.lambda$main$1(Main.java:86)
    at java.lang.Thread.run(Thread.java:745)

    org.apache.http.client.ClientProtocolException
    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:186)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:107)
    at Business.HTTPHandler.Client.send(Client.java:67)
    at main.Main.lambda$main$1(Main.java:86)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.http.ProtocolException: Invalid header: *
    at org.apache.http.impl.io.AbstractMessageParser.parseHeaders(AbstractMessageParser.java:232)
    at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:268)
    at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:165)
    at org.apache.http.impl.conn.CPoolProxy.receiveResponseHeader(CPoolProxy.java:167)
    at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:272)
    at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:124)
    at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:271)
    at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:184)
    at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:88)
    at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
    ... 5 more

    Caused by: org.apache.http.ProtocolException: Invalid header: 13
    at org.apache.http.impl.io.AbstractMessageParser.parseHeaders(AbstractMessageParser.java:232)
    at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:268)
    at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:165)
    at org.apache.http.impl.conn.CPoolProxy.receiveResponseHeader(CPoolProxy.java:167)
    at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:272)
    at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:124)
    at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:271)
    at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:184)
    at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:88)
    at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
    ... 5 more

Answer 1

您的 RequestHandler 类不是线程安全的，这就是为什么它在您运行单线程时有效，而在使用执行程序时失败。

请勿不要将 HttpExchange 对象存储在 sender 变量中。当所有线程都覆盖同一个变量时，它会导致竞争条件，并且可能看到处于错误状态的错误对象(例如，流已经关闭的对象)。

您可以将其作为参数传递给您的方法。您确实不需要额外的变量。