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我已经为 http 服务器编写了一个代码，它假设根据客户端输入向客户端发送响应。

我已经写了两次相同的代码，一次使用简单的套接字连接，第二次使用com.sun.net.httpserver.

基于简单套接字的代码工作正常，我可以使用以下命令读取来自客户端的请求：

DataInputStream in = new DataInputStream (threadSocket.getInputStream());
int ln = in.available();
byte [] bytes  = new byte [ln];
in.read(bytes);
String msg = new String(bytes);

但是，当我尝试使用 httpserver 时，我无法从客户端获得任何输入。

这是 http 服务器处理程序的代码：

static class ntripHandler implements HttpHandler {
    public void handle(HttpExchange t){ 
        try {
            int ln = t.getRequestBody().available();
            byte [] bt  = new byte [ln];
            t.getRequestBody().read(bt);
            String msg = new String(bt);
            System.out.println(msg);
        } 
        catch (IOException ex) {System.out.println(ex);}

        //// some operations sholuld be made here .......

    }
}

目前，我正在尝试使用来自的输入流，HttpExchange.getRequestBody()但它始终为空。我也尝试过，httpExchange.getRequestURI().getQuery()但它也总是为空。

来自客户端的输入如下所示： GET / HTTP/1.0 User-Agent: NTRIP GnssSurferV1.10 Authorization: Basic

我做错了什么，我该如何解决？任何帮助，将不胜感激。

4

1 回答 1

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你应该关闭HttpExchange.

另请注意，您的使用方式available()很棘手。它返回

可以读取的字节数的估计...

和：

请注意，虽然 {@code InputStream} 的某些实现会返回流中的字节总数，但许多不会。使用此方法的返回值来分配旨在保存此流中所有数据的缓冲区是不正确的。

完整示例（不完全是您的用例，但它回答了您的问题）：

/**
 * To test: 
 * 
 * ```` bash
 * $ curl -v -H "Content-Type: application/json" \
 *   -d '{"name":"Testing!"}' http://localhost:8000
 * ````
 */
public static void main(String[] args) throws IOException {
    // Creates a basic HTTP server, with default Executor and system default socket
    // backlog (second parameter in create method, 0)
    final HttpServer server = HttpServer.create(
        new InetSocketAddress("localhost", 8000), 0);
    // context MUST start with "/". Root context is just "/"
    // HttpHandler implemented as lambda, note that HttpHandler#handle() throws an
    // IOException, so no need to catch it
    server.createContext("/", (he) -> {
        try {
            System.out.println(he.getRequestURI());
            final InputStream in = he.getRequestBody();
            final OutputStream out = he.getResponseBody();

            // first send header, than response body, if any
            // use default buffer size suited for your use case
            final byte[] buffer = new byte[in.available() == 0 ? 1024 : in.available()];
            System.out.println("buffer size=" + buffer.length);     

            // preferrable, specify *exact* size of response body. If not known, use 0
            // < HTTP/1.1 200 OK
            // < Date: Thu, 21 Jul 2016 08:14:25 GMT
            // < Transfer-encoding: chunked
//            he.sendResponseHeaders(200, 0);
//            int length;
//            while ((length = in.read(buffer, 0, buffer.length)) >= 0) {
//                out.write(buffer, 0, length);
//            }

            // better way of doing it: buffer response body and set content length
            // < HTTP/1.1 200 OK
            // < Date: Thu, 21 Jul 2016 08:11:40 GMT
            // < Content-length: 19
            final ByteArrayOutputStream baos = new ByteArrayOutputStream(buffer.length);
            int length;
            while ((length = in.read(buffer, 0, buffer.length)) >= 0) {
                baos.write(buffer, 0, length);
            }
            he.sendResponseHeaders(200, baos.size());
            baos.writeTo(out); // no need to close() of flush() ByteArrayOutputStream

        } finally {
            // Essential: HttpExchange must be closed
            he.close();
        }
    });
    server.start();
}
于 2016-07-21T07:24:41.840 回答