如何在Handler中正确读取POST请求的请求体？

Question

我现在使用的代码：

    Pooled<ByteBuffer> pooledByteBuffer = exchange.getConnection().getBufferPool().allocate();
    ByteBuffer byteBuffer = pooledByteBuffer.getResource();

    int limit = byteBuffer.limit();

    byteBuffer.clear();

    exchange.getRequestChannel().read(byteBuffer);
    int pos = byteBuffer.position();
    byteBuffer.rewind();
    byte[] bytes = new byte[pos];
    byteBuffer.get(bytes);

    String requestBody = new String(bytes, Charset.forName("UTF-8") );

    byteBuffer.clear();
    pooledByteBuffer.free();

看起来它运行良好，但我不确定在将ByteBuffer返回到池之前是否需要使用clear()。我甚至不确定是否应该使用exchange.getConnection().getBufferPool().allocate();。文档中对此没有太多信息。

- atok

---

请使用 Exchange.getRequestReceiver().receiveFullBytes(cb, ecb) 函数来异步读取请求体。 - Ravi Upadhyay

Answer 1

更简单的读取请求体的方法是将其分派到工作线程，这使得HttpExchange#getInputStream()可用。

有两种方法可以做到这一点：使用BlockingHandler或在文档中展示的分派模式。以下是使用BlockingHandler的示例： new BlockingHandler(myHandler) BlockingHandler基本上为您完成了分派。

- Mwanji Ezana

Answer 2

为了以非阻塞的方式完成它，请参见io.undertow.io.Receiver接口。处理程序的示例可能如下：

pathHandler.put("/test", new HttpHandler() {
    @Override
    public void handleRequest(HttpServerExchange exchange) throws Exception {
        exchange.getRequestReceiver().receiveFullBytes(new FullBytesCallback() {
            @Override
            public void handle(HttpServerExchange exchange, byte[] message) {
                System.out.println(new String(message));
            }                    
        });

        exchange.getResponseSender().send("Hello World");
    }
});

如果是Java 8：

pathHandler.put("/test", (ex) -> {
    ex.getRequestReceiver().receiveFullBytes((e, m) -> {
        System.out.println(new String(m));
    });
    ex.getResponseSender().send("Hello World");
});

- Mike Shauneu

Answer 3

@atok，我已经使用你的方法一段时间了，但有时在读取调用之前关闭流时，我会得到一个空的正文。这个方法非常好用：

BufferedReader reader = null;
StringBuilder builder = new StringBuilder( );

try {
    exchange.startBlocking( );
    reader = new BufferedReader( new InputStreamReader( exchange.getInputStream( ) ) );

    String line;
    while( ( line = reader.readLine( ) ) != null ) {
        builder.append( line );
    }
} catch( IOException e ) {
    e.printStackTrace( );
} finally {
    if( reader != null ) {
        try {
            reader.close( );
        } catch( IOException e ) {
            e.printStackTrace( );
        }
    }
}

String body = builder.toString( );

- eheck

Answer 4

import io.undertow.Handlers;
import io.undertow.Undertow;
import io.undertow.server.HttpHandler;
import io.undertow.server.HttpServerExchange;
import io.undertow.server.handlers.BlockingHandler;


public static void main(String[] args) {

    Undertow server = Undertow.builder()
            .addHttpListener(8087, "xx.xx.xx.xx")
            .setHandler(Handlers.pathTemplate().add("/webhook", new BlockingHandler(new ItemHandler())))
            .build();
    server.start();
}

static class ItemHandler implements HttpHandler {


    @Override
    public void handleRequest(HttpServerExchange exchange) throws Exception {
       exchange.getInputStream());
    }
}

- Rob Austin