Android CONNECT的意外响应代码：400

我的一些用户在尝试连接时经常遇到这种异常

java.io.IOException: Unexpected response code for CONNECT: 400
    at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.makeTunnel(HttpsURLConnectionImpl.java:509)
    at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.makeSslConnection(HttpsURLConnectionImpl.java:463)
    at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.connect(HttpsURLConnectionImpl.java:442)
    at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
    at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
    at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:81)
    at libcore.net.http.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:165)

URL connectURL = new URL(url);
HttpURLConnection conn = (HttpURLConnection) connectURL.openConnection();
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setInstanceFollowRedirects(true);
conn.setReadTimeout(30000); 
conn.setConnectTimeout(15000);
conn.setRequestMethod("POST");

connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.setRequestProperty("Accept-Encoding", "deflate, gzip");
connection.setRequestProperty("Content-Length", postParameters.length() + "");

conn.connect();

OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(mRequestObj.getPostParameters());
writer.flush();
writer.close();

responseCode = conn.getResponseCode();

BufferedInputStream bis = null;
try {
    bis = new BufferedInputStream(conn.getInputStream());
}
catch(IOException io) {
    if(conn.getErrorStream() != null) 
        bis = new BufferedInputStream(conn.getErrorStream());
    else 
        throw io;
}

... 

400表示请求错误，但几秒钟后相同的请求成功。我仔细检查了请求，没有问题。我还查看了服务器日志，发现请求似乎还没有到达我们的服务器

我正在使用一个简单的

HttpUrlConnection

来连接

java.io.IOException: Unexpected response code for CONNECT: 400
    at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.makeTunnel(HttpsURLConnectionImpl.java:509)
    at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.makeSslConnection(HttpsURLConnectionImpl.java:463)
    at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.connect(HttpsURLConnectionImpl.java:442)
    at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
    at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
    at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:81)
    at libcore.net.http.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:165)

URL connectURL = new URL(url);
HttpURLConnection conn = (HttpURLConnection) connectURL.openConnection();
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setInstanceFollowRedirects(true);
conn.setReadTimeout(30000); 
conn.setConnectTimeout(15000);
conn.setRequestMethod("POST");

connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.setRequestProperty("Accept-Encoding", "deflate, gzip");
connection.setRequestProperty("Content-Length", postParameters.length() + "");

conn.connect();

OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(mRequestObj.getPostParameters());
writer.flush();
writer.close();

responseCode = conn.getResponseCode();

BufferedInputStream bis = null;
try {
    bis = new BufferedInputStream(conn.getInputStream());
}
catch(IOException io) {
    if(conn.getErrorStream() != null) 
        bis = new BufferedInputStream(conn.getErrorStream());
    else 
        throw io;
}

... 

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还有其他人面临这个问题吗？有什么可以帮忙的吗

这是个老问题，但也许有人会觉得它很有用

由于代理隧道由于某种原因失败，引发了异常。这就是为什么您的web服务器没有显示任何内容，根本无法访问它

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以下描述涉及连接方法类型：

本规范保留方法名称CONNECT供使用 使用可以动态切换为隧道的代理

它是从我的书里抄来的

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不幸的是，除非您能够控制代理服务器，否则您无法对此做很多事情。您可以做的是捕获异常并重试连接。

我遇到了相同的问题。有什么想法吗？我遇到了同样的错误，我处理它的方式是捕获IOException并检查连接是否为https，然后重试。考虑到IOException过于泛化，有没有更好的方法捕获这个错误？我想IOException应该可以