尽管将 POST 设置为方法类型，但 HttpUrlConnection 类仍执行 GET答案

【问题标题】：HttpUrlConnection class performs GET despite setting POST as method type尽管将 POST 设置为方法类型，但 HttpUrlConnection 类仍执行 GET
【发布时间】：2017-08-31 13:13:41
【问题描述】：

我正在尝试使用同时具有 GET 和 POST 请求处理程序的 API。当我尝试执行 GET 请求时，如下所示：

HttpsURLConnection httpURLConnection = (HttpsURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("GET");
httpURLConnection.connect();

我得到了正确的 Cookies 以及 HTML 响应。

但现在我尝试在同一个 url 上执行 POST 请求，如下所示：

String postBody = "__RequestVerificationToken=" + __RequestVerificationToken + "&Username=" + userName
            + "&Password=" + passWord;
byte[] postData = postBody.getBytes(StandardCharsets.UTF_8);

HttpsURLConnection httpURLConnection = (HttpsURLConnection) url.openConnection();
httpURLConnection.setDoOutput(true);
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
httpURLConnection.setRequestProperty("charset", "utf-8");
httpURLConnection.setRequestProperty("Content-Length", Integer.toString(postData.length));
httpURLConnection.setUseCaches(false);

/**
 * write the request body as bytes
 */
OutputStream os = httpURLConnection.getOutputStream();
os.write(postBody.getBytes());
os.flush();
os.close();

我在 Cookies 和 HTML 响应 中得到的所有内容与我之前在 GET 请求中收到的内容相同。

有人能解释一下发生了什么吗？

【问题讨论】：

标签： java post https get httpurlconnection

【解决方案1】：

您需要添加 httpURLConnection.setDoInput(true);

<!-- language: java -->
String postBody = "__RequestVerificationToken=" + __RequestVerificationToken + "&Username=" + userName
            + "&Password=" + passWord;
byte[] postData = postBody.getBytes(StandardCharsets.UTF_8);

HttpsURLConnection httpURLConnection = (HttpsURLConnection) url.openConnection();
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
httpURLConnection.setRequestProperty("charset", "utf-8");
httpURLConnection.setRequestProperty("Content-Length", Integer.toString(postData.length));
httpURLConnection.setUseCaches(false);

/**
 * write the request body as bytes
 */
OutputStream os = httpURLConnection.getOutputStream();
os.write(postBody.getBytes());
os.flush();
os.close();

【讨论】：

具体在哪里？在 POST 调用时？
` httpURLConnection.setDoOutput(true); httpURLConnection.setDoInput(true); ... `