問題描述

有沒有辦法獲取原始響應 http 標頭?

getHeaderField() 方法對我不起作用，因為服務器吐出多個Set-Cookie"，其中一些會丟失.

getHeaderField() 方法對我不起作用

您是在 <代碼>java.net.URLConnection，是嗎?不，使用 URLconnection 無法獲取原始 HTTP 響應標頭.您需要退回到低級別的 Socket 編程.這是一個SSCCE，只需復制'n'paste'n'運行它.

包com.stackoverflow.q2307291;導入 java.io.BufferedReader；導入 java.io.IOException；導入 java.io.InputStreamReader；導入 java.io.OutputStreamWriter；導入 java.io.PrintWriter；導入 java.net.Socket；公共類測試{公共靜態(tài) void main(String[] args) 拋出 IOException {字符串主機名 = stackoverflow.com"；國際端口 = 80；套接字套接字 = null;PrintWriter 作家 = null;BufferedReader 閱讀器 = null;嘗試 {套接字 = 新套接字(主機名，端口)；writer = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()));writer.println("GET/HTTP/1.1");writer.println("主機:" + 主機名);writer.println("接受:*/*");writer.println("用戶代理:Java");//說實話.writer.println("");//重要，否則服務器會期望請求中包含更多內容.writer.flush();reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));for (String line; (line = reader.readLine()) != null;) {if (line.isEmpty()) 中斷；//當標題完成時停止.我們對所有的 HTML 不感興趣.System.out.println(line);}} 最后 {if (reader != null) try { reader.close();} 捕捉(IOException logOrIgnore){}if (writer != null) { writer.close();}if (socket != null) try { socket.close();} 捕捉(IOException logOrIgnore){}}}}

為避免每個嘗試此代碼段的人都使 SO 過載，輸出如下所示:

要了解有關以低級方式發(fā)送 HTTP 請求的更多信息，請閱讀 HTTP 規(guī)范.

但是，您可能想使用 getHeaderFields() 方法來檢索具有多個值的標頭.<代碼>getHeaderField() 即只返回最后一個值，根據鏈接的 API 文檔.

列表<字符串>cookies = connection.getHeaderFields().get("Set-Cookie");

Is there any way to get raw response http header?

The getHeaderField() method doesn't work for me, because server spits multiple 'Set-Cookie' and some of them get lost.

The getHeaderField() method doesn't work for me

You're asking this in the context of java.net.URLConnection, is it? No, obtaining the raw HTTP response headers is not possible with URLconnection. You'll need to fall back to low-level Socket programming. Here's an SSCCE, just copy'n'paste'n'run it.

package com.stackoverflow.q2307291;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;

public class Test {

    public static void main(String[] args) throws IOException {
        String hostname = "stackoverflow.com";
        int port = 80;

        Socket socket = null;
        PrintWriter writer = null;
        BufferedReader reader = null;

        try {
            socket = new Socket(hostname, port);
            writer = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()));
            writer.println("GET / HTTP/1.1");
            writer.println("Host: " + hostname);
            writer.println("Accept: */*");
            writer.println("User-Agent: Java"); // Be honest.
            writer.println(""); // Important, else the server will expect that there's more into the request.
            writer.flush();

            reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            for (String line; (line = reader.readLine()) != null;) {
                if (line.isEmpty()) break; // Stop when headers are completed. We're not interested in all the HTML.
                System.out.println(line);
            }
        } finally {
            if (reader != null) try { reader.close(); } catch (IOException logOrIgnore) {} 
            if (writer != null) { writer.close(); }
            if (socket != null) try { socket.close(); } catch (IOException logOrIgnore) {} 
        }
    }

}

To avoid SO being overloaded by everyone trying this snippet, here's how the output will look like:

HTTP/1.1 200 OK
Cache-Control: private
Content-Type: text/html; charset=utf-8
Expires: Sun, 21 Feb 2010 20:39:08 GMT
Server: Microsoft-IIS/7.5
Date: Sun, 21 Feb 2010 20:39:07 GMT
Connection: close
Content-Length: 208969

To learn more about sending HTTP requests the low-level way, read the HTTP specification.

However, you probably want to make use of getHeaderFields() method instead to retrieve a header with multiple values. The getHeaderField() namely only returns the last value, as per the linked API doc.

List<String> cookies = connection.getHeaderFields().get("Set-Cookie");

這篇關于獲取原始 HTTP 響應標頭的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！