为什么代码抛出“读取输入后无法写入输出”错误?

firstHttpConn 检查响应代码并打开 secondHttpConn . 如果响应代码为401,则将基本身份验证标头添加到 第二个HTTPCONN . 然后发布数据并读取响应。

Cannot write output after reading input 错误我检查了关于堆栈溢出的其他问题,如 this one 我确信我没有犯同样的错误。

//I hate using Java 6 and HttpURLConnection, but the code is for a very old system.
private static XmlObject callWebService(String soapMessage, String webServiceEndpoint, String soapAction) throws Exception {
    XmlObject resultXMLObject;
    HttpURLConnection firstHttpConn = null;
    HttpURLConnection secondHttpConn = null;

    try {
        byte[] streamoutByteArray = soapMessage.getBytes("UTF-8");

        URL url = new URL(webServiceEndpoint);
        firstHttpConn = (HttpURLConnection) url.openConnection();
        firstHttpConn.connect();

        if (firstHttpConn.getResponseCode() == 401) {
            firstHttpConn.disconnect();
            secondHttpConn = (HttpURLConnection) url.openConnection();
            secondHttpConn.setRequestProperty("Authorization", "Basic " + getBasicAuth());
        } else {
            firstHttpConn.disconnect();
            secondHttpConn = (HttpURLConnection) url.openConnection();
        }

        secondHttpConn.setConnectTimeout(30000);
        secondHttpConn.setReadTimeout(300000);
        secondHttpConn.setRequestProperty("Content-Length", String.valueOf(streamoutByteArray.length));
        secondHttpConn.setRequestProperty("Content-Type", "text/xml; charset=UTF-8);
        secondHttpConn.setRequestProperty("SOAPAction", soapAction);
        secondHttpConn.setRequestMethod("POST");
        secondHttpConn.setDoOutput(true);
        secondHttpConn.setDoInput(true);

        OutputStream out = secondHttpConn.getOutputStream();
        out.write(streamoutByteArray);
        out.close();

        //Line 238 below.
        InputStreamReader isr = new InputStreamReader(secondHttpConn.getInputStream());
        BufferedReader in = new BufferedReader(isr);
        String inputLine;
        StringBuffer sb = new StringBuffer();

        while ((inputLine = in.readLine()) != null)
            sb.append(inputLine).append("\n");

        in.close();
        resultXMLObject = XmlObject.Factory.parse(sb.toString());
    } finally {
        if (firstHttpConn != null)
            firstHttpConn.disconnect();
        if (secondHttpConn != null)
            secondHttpConn.disconnect();
    }

    return resultXMLObject;
}

Caused By: java.net.ProtocolException: Cannot write output after reading input.
        at weblogic.net.http.HttpURLConnection.getOutputStream(HttpURLConnection.java:271)
        at org.company.member.esb.webservice.WebServiceClient.callWebService(WebServiceClient.java:238)
        at org.company.member.esb.webservice.WebServiceClient.invokeWebserviceV01(WebServiceClient.java:132)
        at sun.reflect.GeneratedMethodAccessor711.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        Truncated. see log file for complete stacktrace