java - 在 Java 程序中使用 curl

Question

对于一项作业，我必须创建一个使用 rest 的程序。这是老师给我的代码，让我们开始这项作业，所以下面的代码应该是正确的。

import java.io.*;
import java.net.InetSocketAddress;
import java.util.*;
import java.util.concurrent.Executors;

import com.sun.net.httpserver.*;

public class HttpServerDemo {
    public static void main(String[] args) throws IOException {
        InetSocketAddress addr = new InetSocketAddress(8080);
        HttpServer server = HttpServer.create(addr, 0);
        server.createContext( "/", new RootHandler());  
        server.createContext( "/foo/", new FooHandler());   
        server.setExecutor( Executors.newCachedThreadPool());
        server.start();
        System.out.println("Server is listening on port 8080" );
    }

    public static void printHeaders( HttpExchange exchange, PrintStream response) {
        Headers requestHeaders = exchange.getRequestHeaders();
        Set<String> keySet = requestHeaders.keySet();
        Iterator<String> iter = keySet.iterator();
        while( iter.hasNext()) {
            String key = iter.next();
            response.println( key + " = " + requestHeaders.get(key));
        }
    }
    public static void printBody( HttpExchange exchange, PrintStream response) throws IOException {
        BufferedReader body = new BufferedReader( new InputStreamReader( exchange.getRequestBody()));
        String bodyLine;
        while( (bodyLine = body.readLine()) != null) {
            response.println( bodyLine);
        }
    }
}

class RootHandler implements HttpHandler {
    public void handle( HttpExchange exchange) throws IOException {
        String requestMethod = exchange.getRequestMethod();

        Headers responseHeaders = exchange.getResponseHeaders();
        responseHeaders.set( "Content-Type", "text/plain");
        exchange.sendResponseHeaders( 200, 0);

        PrintStream response = new PrintStream( exchange.getResponseBody());
        response.println( "context: ROOT; method: " + requestMethod);
        response.println( "--- headers ---");
        HttpServerDemo.printHeaders( exchange, response);
        if( requestMethod.equalsIgnoreCase( "POST")) {
            response.println( "=== body ===");
            HttpServerDemo.printBody( exchange, response);
        }
        response.close();
    }   
}

class FooHandler implements HttpHandler {
    public void handle( HttpExchange exchange) throws IOException {
        String requestMethod = exchange.getRequestMethod();

        Headers responseHeaders = exchange.getResponseHeaders();
        responseHeaders.set( "Content-Type", "text/plain");
        exchange.sendResponseHeaders( 200, 0);

        PrintStream response = new PrintStream( exchange.getResponseBody());
        response.println( "context: FOO; method: " + requestMethod);
        HttpServerDemo.printHeaders( exchange, response);
        response.close();
    }   
}

由于 RootHandler 类有一个检查“POST”的 if 语句，我将使用它来测试它。所以当我从一个单独的终端使用 curl 与这个程序通信时，我输入:

curl –d "message=helloworld" http://localhost:8080/

我得到这个作为返回:

curl: (6) Could not resolve host: –d; nodename nor servname provided, or not known
curl: (6) Could not resolve host: message=helloworld; nodename nor servname provided, or not known
context: ROOT; method: GET
--- headers ---
Host = [localhost:8080]
User-agent = [curl/7.21.4 (universal-apple-darwin11.0) libcurl/7.21.4 OpenSSL/0.9.8r zlib/1.2.5]
Accept = [*/*]

当我从我的终端使用 curl 时，我觉得我犯了错误。通过查看错误，它没有采用我提供的“-d”选项，它导致程序将请求方法读取为“GET”而不是“POST”。我对“DELETE”和“PUT”请求方法进行了尝试，得到了相同的结果。

Answer 1

这不是破折号:

curl –d "message=helloworld" http://localhost:8080/ # Not a dash
curl -d "message=helloworld" http://localhost:8080/ # Is a dash

应该清楚代码是完全不相关的，因为您得到的错误来自 curl。

虽然代码应该是正确的，但这并不意味着它是。不要仅仅因为你从老师、书本、网站等那里得到它就相信它。各种各样的事情都可能出错，比如剪切和粘贴问题，这很可能是你的 curl 还有命令。