我想在 Java 中使用具有基本身份验证(用户名、密码)的代理进行连接(并且仅此连接)。以下代码适用于 HTTP URL(例如“http://www.google.com”):

URL url = new URL("http://www.google.com");
HttpURLConnection httpURLConnection = null;
InetSocketAddress proxyLocation = new InetSocketAddress(proxyHost, proxyPort);
Proxy proxy = new Proxy(Proxy.Type.HTTP, proxyLocation);
httpURLConnection = (HttpURLConnection) url.openConnection(proxy);
// Works for HTTP only! Doesn't work for HTTPS!
String encoded = new sun.misc.BASE64Encoder().encodeBuffer((proxyUserName + ":" + proxyPassword).getBytes()).replace("\r\n", "");
httpURLConnection.setRequestProperty("Proxy-Authorization", "Basic " + encoded);
InputStream is = httpURLConnection.getInputStream();
InputStreamReader isr = new InputStreamReader(is); 
int data = isr.read();
while(data != -1){
  char c = (char) data;
  data = isr.read();
  System.out.print(c);
}
isr.close();

该代码不适用于 HTTPS URL(例如“https://www.google.com”)，但是!我得到 java.io.IOException: Unable to tunnel through proxy。当我尝试访问 HTTPS URL 时，代理返回“需要 HTTP/1.0 407 代理身份验证”。

此代码适用于 HTTP 和 HTTPS:

URL url = new URL("https://www.google.com");
HttpURLConnection httpURLConnection = null;
InetSocketAddress proxyLocation = new InetSocketAddress(proxyHost, proxyPort);
Proxy proxy = new Proxy(Proxy.Type.HTTP, proxyLocation);
httpURLConnection = (HttpURLConnection) url.openConnection(proxy);
// Works for HTTP and HTTPS, but sets a global default!
Authenticator.setDefault(new Authenticator() {
  protected PasswordAuthentication getPasswordAuthentication() {
    return new PasswordAuthentication(proxyUserName, proxyPassword.toCharArray());
  }
});
InputStream is = httpURLConnection.getInputStream();
InputStreamReader isr = new InputStreamReader(is); 
int data = isr.read();
while(data != -1){
  char c = (char) data;
  data = isr.read();
  System.out.print(c);
}
isr.close();

第二个代码的问题是它设置了一个新的默认 Authenticator 我不想这样做，因为这个代理只被应用程序的一部分和不同的部分使用的应用程序可能正在使用不同的代理。我不想为整个应用程序设置全局默认值。有没有办法让第一个代码与 HTTPS 一起使用，或者使用 Authenticator 而不将其设置为默认值？

我必须使用 java.net.HttpURLConnection，因为我重写了一个必须返回 HttpURLConnection 的类的方法，所以我不能使用Apache HttpClient。

最佳答案

您可以扩展 ProxiedHttpsConnection 并自己处理所有低级相关的东西。

需要执行以下步骤才能通过 HTTP 代理连接到 https 网站:

注意:与代理和http服务器的通信应该在ASCII7 .

1. 发送CONNECT stackoverflow.com:443 HTTP/1.0\r\n到代理
2. 发送您的身份验证:代理授权:基本 c2F5WW91SGF2ZVNlZW5UaGlzSW5UaGVDb21tZW50cw==\r\n。
3. 结束第一个请求:\r\n
4. 读取来自代理的响应，直到看到组合“\r\n\r\n”。
5. 解析您从代理获得的响应的第一行，并检查它是否以 HTTP/1.0 200 开头。
6. 在现有连接上启动 SSL session 。
7. 发送一个 http 请求的开始:GET/questions/3304006/persistent-httpurlconnection-in-java HTTP/1.0\r\n
8. 设置正确的 Host header :Host: stackoverflow.com\r\n
9. 结束对http服务器的请求:\r\n
10. 读取到 \r\n 并将第一行解析为状态消息
11. 读取到请求正文的流结束

当我们要实现 HttpUrlConnection 类时，我们还需要考虑以下几点:

• 在构建类时，该类应该存储数据以供将来连接，但不能直接建立
• 任何方法都可以按任何顺序调用
• OutputStream的关闭意味着数据传输完成，而不是连接必须完成
• 每个 api 以不同的顺序使用方法
• HTTP header 不区分大小写，Java 映射区分大小写。

快说，有很多陷阱

在我设计的类中，它使用 boolean 标志来记住是否调用了 connect 方法和 afterPostClosure 方法，它还支持 if getInputStream( ) 在 OutputStream 关闭之前被调用。

这个类还对套接字返回的流使用尽可能少的包装，以防止变得非常复杂。

public class ProxiedHttpsConnection extends HttpURLConnection {

    private final String proxyHost;
    private final int proxyPort;
    private static final byte[] NEWLINE = "\r\n".getBytes();//should be "ASCII7"

    private Socket socket;
    private final Map<String, List<String>> headers = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
    private final Map<String, List<String>> sendheaders = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
    private final Map<String, List<String>> proxyheaders = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
    private final Map<String, List<String>> proxyreturnheaders = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
    private int statusCode;
    private String statusLine;
    private boolean isDoneWriting;

    public ProxiedHttpsConnection(URL url,
            String proxyHost, int proxyPort, String username, String password)
            throws IOException {
        super(url);
        socket = new Socket();
        this.proxyHost = proxyHost;
        this.proxyPort = proxyPort;
        String encoded = Base64.encode((username + ":" + password).getBytes())
                .replace("\r\n", "");
        proxyheaders.put("Proxy-Authorization", new ArrayList<>(Arrays.asList("Basic " + encoded)));
    }

    @Override
    public OutputStream getOutputStream() throws IOException {
        connect();
        afterWrite();
        return new FilterOutputStream(socket.getOutputStream()) {
            @Override
            public void write(byte[] b, int off, int len) throws IOException {
                out.write(String.valueOf(len).getBytes());
                out.write(NEWLINE);
                out.write(b, off, len);
                out.write(NEWLINE);
            }

            @Override
            public void write(byte[] b) throws IOException {
                out.write(String.valueOf(b.length).getBytes());
                out.write(NEWLINE);
                out.write(b);
                out.write(NEWLINE);
            }

            @Override
            public void write(int b) throws IOException {
                out.write(String.valueOf(1).getBytes());
                out.write(NEWLINE);
                out.write(b);
                out.write(NEWLINE);
            }

            @Override
            public void close() throws IOException {
                afterWrite();
            }

        };
    }

    private boolean afterwritten = false;

    @Override
    public InputStream getInputStream() throws IOException {
        connect();
        return socket.getInputStream();

    }

    @Override
    public void setRequestMethod(String method) throws ProtocolException {
        this.method = method;
    }

    @Override
    public void setRequestProperty(String key, String value) {
        sendheaders.put(key, new ArrayList<>(Arrays.asList(value)));
    }

    @Override
    public void addRequestProperty(String key, String value) {
        sendheaders.computeIfAbsent(key, l -> new ArrayList<>()).add(value);
    }

    @Override
    public Map<String, List<String>> getHeaderFields() {
        return headers;
    }

    @Override
    public void connect() throws IOException {
        if (connected) {
            return;
        }
        connected = true;
        socket.setSoTimeout(getReadTimeout());
        socket.connect(new InetSocketAddress(proxyHost, proxyPort), getConnectTimeout());
        StringBuilder msg = new StringBuilder();
        msg.append("CONNECT ");
        msg.append(url.getHost());
        msg.append(':');
        msg.append(url.getPort() == -1 ? 443 : url.getPort());
        msg.append(" HTTP/1.0\r\n");
        for (Map.Entry<String, List<String>> header : proxyheaders.entrySet()) {
            for (String l : header.getValue()) {
                msg.append(header.getKey()).append(": ").append(l);
                msg.append("\r\n");
            }
        }

        msg.append("Connection: close\r\n");
        msg.append("\r\n");
        byte[] bytes;
        try {
            bytes = msg.toString().getBytes("ASCII7");
        } catch (UnsupportedEncodingException ignored) {
            bytes = msg.toString().getBytes();
        }
        socket.getOutputStream().write(bytes);
        socket.getOutputStream().flush();
        byte reply[] = new byte[200];
        byte header[] = new byte[200];
        int replyLen = 0;
        int headerLen = 0;
        int newlinesSeen = 0;
        boolean headerDone = false;
        /* Done on first newline */
        InputStream in = socket.getInputStream();
        while (newlinesSeen < 2) {
            int i = in.read();
            if (i < 0) {
                throw new IOException("Unexpected EOF from remote server");
            }
            if (i == '\n') {
                if (newlinesSeen != 0) {
                    String h = new String(header, 0, headerLen);
                    String[] split = h.split(": ");
                    if (split.length != 1) {
                        proxyreturnheaders.computeIfAbsent(split[0], l -> new ArrayList<>()).add(split[1]);
                    }
                }
                headerDone = true;
                ++newlinesSeen;
                headerLen = 0;
            } else if (i != '\r') {
                newlinesSeen = 0;
                if (!headerDone && replyLen < reply.length) {
                    reply[replyLen++] = (byte) i;
                } else if (headerLen < reply.length) {
                    header[headerLen++] = (byte) i;
                }
            }
        }

        String replyStr;
        try {
            replyStr = new String(reply, 0, replyLen, "ASCII7");
        } catch (UnsupportedEncodingException ignored) {
            replyStr = new String(reply, 0, replyLen);
        }

        // Some proxies return http/1.1, some http/1.0 even we asked for 1.0
        if (!replyStr.startsWith("HTTP/1.0 200") && !replyStr.startsWith("HTTP/1.1 200")) {
            throw new IOException("Unable to tunnel. Proxy returns \"" + replyStr + "\"");
        }
        SSLSocket s = (SSLSocket) ((SSLSocketFactory) SSLSocketFactory.getDefault())
                .createSocket(socket, url.getHost(), url.getPort(), true);
        s.startHandshake();
        socket = s;
        msg.setLength(0);
        msg.append(method);
        msg.append(" ");
        msg.append(url.toExternalForm().split(String.valueOf(url.getPort()), -2)[1]);
        msg.append(" HTTP/1.0\r\n");
        for (Map.Entry<String, List<String>> h : sendheaders.entrySet()) {
            for (String l : h.getValue()) {
                msg.append(h.getKey()).append(": ").append(l);
                msg.append("\r\n");
            }
        }
        if (method.equals("POST") || method.equals("PUT")) {
            msg.append("Transfer-Encoding: Chunked\r\n");
        }
        msg.append("Host: ").append(url.getHost()).append("\r\n");
        msg.append("Connection: close\r\n");
        msg.append("\r\n");
        try {
            bytes = msg.toString().getBytes("ASCII7");
        } catch (UnsupportedEncodingException ignored) {
            bytes = msg.toString().getBytes();
        }
        socket.getOutputStream().write(bytes);
        socket.getOutputStream().flush();
    }

    private void afterWrite() throws IOException {
        if (afterwritten) {
            return;
        }
        afterwritten = true;
        socket.getOutputStream().write(String.valueOf(0).getBytes());
        socket.getOutputStream().write(NEWLINE);
        socket.getOutputStream().write(NEWLINE);
        byte reply[] = new byte[200];
        byte header[] = new byte[200];
        int replyLen = 0;
        int headerLen = 0;
        int newlinesSeen = 0;
        boolean headerDone = false;
        /* Done on first newline */
        InputStream in = socket.getInputStream();
        while (newlinesSeen < 2) {
            int i = in.read();
            if (i < 0) {
                throw new IOException("Unexpected EOF from remote server");
            }
            if (i == '\n') {
                if (headerDone) {
                    String h = new String(header, 0, headerLen);
                    String[] split = h.split(": ");
                    if (split.length != 1) {
                        headers.computeIfAbsent(split[0], l -> new ArrayList<>()).add(split[1]);
                    }
                }
                headerDone = true;
                ++newlinesSeen;
                headerLen = 0;
            } else if (i != '\r') {
                newlinesSeen = 0;
                if (!headerDone && replyLen < reply.length) {
                    reply[replyLen++] = (byte) i;
                } else if (headerLen < header.length) {
                    header[headerLen++] = (byte) i;
                }
            }
        }

        String replyStr;
        try {
            replyStr = new String(reply, 0, replyLen, "ASCII7");
        } catch (UnsupportedEncodingException ignored) {
            replyStr = new String(reply, 0, replyLen);
        }

        /* We asked for HTTP/1.0, so we should get that back */
        if ((!replyStr.startsWith("HTTP/1.0 200")) && !replyStr.startsWith("HTTP/1.1 200")) {
            throw new IOException("Server returns \"" + replyStr + "\"");
        }
    }

    @Override
    public void disconnect() {
        try {
            socket.close();
        } catch (IOException ex) {
            Logger.getLogger(ProxiedHttpsConnection.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    @Override
    public boolean usingProxy() {
        return true;
    }
}

上述代码的当前错误:

• 在发布期间不会因错误而关闭流
• 在与代理的初始联系发生错误期间不会关闭流
• 不支持 http 重定向
• 它不支持 http 1.1 的东西，比如 chunked 和 gzip 编码，但这没问题，因为我们宣布自己是 http1.0 客户端。

上面的代码可以这样使用:

    ProxiedHttpsConnection n = new ProxiedHttpsConnection(
            new URL("https://stackoverflow.com:443/questions/3304006/persistent-httpurlconnection-in-java"), 
            "proxy.example.com", 8080, "root", "flg83yvem#");
    n.setRequestMethod("GET");
    n.addRequestProperty("User-Agent", "Java test https://stackoverflow.com/users/1542723/ferrybig");
    //try (OutputStream out = n.getOutputStream()) {
    //  out.write("Hello?".getBytes());
    //}
    try (InputStream in = n.getInputStream()) {
        byte[] buff = new byte[1024];
        int length;
        while ((length = in.read(buff)) >= 0) {
            System.out.write(buff, 0, length);
        }
    }

如果你打算将它与一种代理选择器一起使用，你应该检查 url 的协议(protocol)，看看它是 http 还是 https，如果是 http，不要使用这个类，而是手动附加 header 喜欢:

httpURLConnection.setRequestProperty("Proxy-Authorization", "Basic " + encoded);

为什么不使用 httpsUrlConnection.setSSLSocketFactory

虽然 java 有这个方法，但尝试使用它会告诉你为什么它不起作用，java 只是不停地调用 createSocket(Socket s, String host, int port, boolean autoClose)连接已经打开，因此无法手动执行代理操作。

关于java - HTTPS URL 的基本代理身份验证返回 HTTP/1.0 407 需要代理身份验证，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34877470/