HttpURLConnection POST 请求 - 无法将数据发送到服务器答案

【问题标题】：HttpURLConnection POST request - cannot send data to serverHttpURLConnection POST 请求 - 无法将数据发送到服务器
【发布时间】：2015-04-05 05:48:44
【问题描述】：

我有这个代码：

HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(10000);
conn.setConnectTimeout(10000);
conn.setRequestMethod(type);
conn.setDoOutput(output);
if(output)
   conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setDoInput(true);

conn.connect();

OutputStream out = null;
if(output)
   out = conn.getOutputStream();
InputStream in = conn.getInputStream();

if(output) {
    BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(out, "UTF-8"));
    bw.write(getQuery(params));
    bw.flush();
}

// Get output
BufferedReader br = new BufferedReader(new InputStreamReader(in));
StringBuilder sb = new StringBuilder();
String line;
while((line = br.readLine()) != null) {
    sb.append(line);
    sb.append("\n");
}

in.close();
if(output)
    out.close();

// Do stuff with the output

当output 为真（执行 POST 或 PUT 请求）且未完成请求时，此代码会引发 IOException。我尝试对conn.connect()、写调用和流创建块进行重新排序，但没有进行任何排列。

在所有情况下，BufferedReader 都可以正常工作并且不会引发任何异常。 getQuery 正确返回一个 URL 编码的字符串。

这是来自 IOException 的堆栈跟踪：

java.io.IOException: closed
W/System.err﹕ at com.android.okio.RealBufferedSink$1.write(RealBufferedSink.java:129)
W/System.err﹕ at java.io.OutputStreamWriter.flushBytes(OutputStreamWriter.java:167)
W/System.err﹕ at java.io.OutputStreamWriter.flush(OutputStreamWriter.java:158)
W/System.err﹕ at java.io.BufferedWriter.flush(BufferedWriter.java:124)
W/System.err﹕ at org.project.NetworkHelper.doRequest(NetworkHelper.java:57)
W/System.err﹕ at java.lang.Thread.run(Thread.java:818)

最终发生的情况是请求通过了，但没有任何 POST 或 PUT 数据最终到达服务器 - 就像写入调用从未发生过一样。

有谁知道是什么原因造成的，或者如何解决？

【问题讨论】：

标签： java android httpurlconnection

【解决方案1】：

你把代码弄复杂了。这是openConnection() 实现的示例。

        byte[] postData = urlParameters.getBytes(Charset.forName("UTF-8"));
        int postDataLength = postData.length;
        JSONArray jsonArray = null;
        try {
            URL url = new URL(request);
            HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
            httpURLConnection.setDoOutput(true);
            httpURLConnection.setDoInput(true);
            httpURLConnection.setInstanceFollowRedirects(false);
            httpURLConnection.setRequestMethod("POST");
            httpURLConnection.setRequestProperty("Content-Type",
                    "application/x-www-form-urlencoded");
            httpURLConnection.setRequestProperty("charset", "utf-8");
            httpURLConnection.setRequestProperty("Content-Length",
                    Integer.toString(postDataLength));
            httpURLConnection.setConnectTimeout(10000);
            DataOutputStream dataOutputStream = new DataOutputStream(
                    httpURLConnection.getOutputStream());
            dataOutputStream.write(postData);
            dataOutputStream.flush();
            dataOutputStream.close();
            if (httpURLConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                InputStream responseStream = new BufferedInputStream(
                        httpURLConnection.getInputStream());
                BufferedReader responseStreamReader = new BufferedReader(
                        new InputStreamReader(responseStream));
                //get output
            }
        } catch (Exception e) {
            Customs.mToast(context, "Server down! Try after some time");
            e.printStackTrace();
        }

【讨论】：