java - 如何在服务器端调用带有多部分请求的 URL，其中有一个包含文件内容的字符串而不是文件

Question

我的 servlet 中有一个 xml 文件内容作为字符串，我需要使用 multipart post 请求调用另一个 URL 以将其作为 xml 文件上传。

有什么办法可以做到吗？

目前这就是我正在做的

private def createConfiguration(def sessiontoken)
{
    /*reqParams is request.getParameterMap(), fileParams is again a map*/
    def charset = "UTF-8";
    def query = String.format("emailaddress=%s&projectid=%s&cfgname=%s&cfgdesc=%s&cfgfile=%s",
        URLEncoder.encode(sessiontoken, charset),
        URLEncoder.encode(reqParams.c_Cfgname[0], charset),
        URLEncoder.encode(reqParams.c_Cfgdesc[0], charset),
        URLEncoder.encode(reqParams.c_Cfgtype[0], charset),
        URLEncoder.encode(reqParams.CFGFILE[0], charset),)

    URLConnection connection = new URL(fileParams.login).openConnection()
    connection.setDoOutput(true)
    connection.setRequestProperty("Accept-Charset", charset)
    connection.setRequestProperty("Content-Type", "multipart/form-data;charset=" + charset)
    try {
        connection.getOutputStream().write(query.getBytes(charset))
    }
    finally {
        connection.getOutputStream().close()
    }
    InputStream response = connection.getInputStream()
    def xmlString=response.getText()
    xmlString
}

下面是抓取到的异常

严重:servlet RedirectRequest 的 Servlet.service() 抛出异常java.io.IOException:服务器返回 HTTP 响应代码:800 URL:http://abhishek157:10070/project/create.action在 sun.net.www.protocol.http.HttpURLConnection.getInputStream(未知来源)在 sun.net.www.protocol.http.HttpURLConnection$getInputStream.call(未知来源)..

更新

得到这个非常有用 link by BalusC所以我用了它。

private def getStreamFromString(str)
{
    // convert String into InputStream
    InputStream is = new ByteArrayInputStream(str.getBytes())
    is
}

private def createConfiguration(def sessiontoken)
{


    println "ok good $sessiontoken"
    def charset = "UTF-8"
    def boundary = Long.toHexString(System.currentTimeMillis())
    def CRLF = "\r\n"
    String param = "value"

    URLConnection connection = new URL(fileParams.create).openConnection()
    println fileParams.create
    connection.setDoOutput(true)
    connection.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
    PrintWriter writer = null
    try {

        OutputStream output = connection.getOutputStream()
        writer = new PrintWriter(new OutputStreamWriter(output, charset), true)

        // Sending normal param.
        writer.append("--" + boundary).append(CRLF)
        writer.append("Content-Disposition: form-data; name=\"sessiontoken\"$CRLF$CRLF$sessiontoken").append(CRLF)
        //writer.append("Content-Type: text/plain; charset=" + charset).append(CRLF)
        writer.append(CRLF)
        writer.append(param).append(CRLF).flush()

        writer.append("--" + boundary).append(CRLF)
        writer.append("Content-Disposition: form-data; name=\"cfgname\"$CRLF$CRLF${reqParams.c_Cfgname[0]}").append(CRLF)
        //writer.append("Content-Type: text/plain; charset=" + charset).append(CRLF)
        writer.append(CRLF)
        writer.append(param).append(CRLF).flush()

        writer.append("--" + boundary).append(CRLF)
        writer.append("Content-Disposition: form-data; name=\"cfgdesc\"$CRLF$CRLF${reqParams.c_Cfgdesc[0]}").append(CRLF)
        //writer.append("Content-Type: text/plain; charset=" + charset).append(CRLF)
        writer.append(CRLF)
        writer.append(param).append(CRLF).flush()

        writer.append("--" + boundary).append(CRLF)
        writer.append("Content-Disposition: form-data; name=\"cfgenv\"$CRLF$CRLF${reqParams.c_Cfgtype[0]}").append(CRLF)
        //writer.append("Content-Type: text/plain; charset=" + charset).append(CRLF)
        writer.append(CRLF)
        writer.append(param).append(CRLF).flush()

        // Sending xml file.
        writer.append("--" + boundary).append(CRLF)
        writer.append("Content-Disposition: form-data; name=\"cfgfile\"; filename=\"" + reqParams.FILENAME[0] + "\"").append(CRLF)
        writer.append("Content-Type: text/xml; charset=" + charset).append(CRLF)
        writer.append(CRLF).flush()
        BufferedReader reader = null
        try {
            reader = new BufferedReader(new InputStreamReader(getStreamFromString(reqParams.CFGFILE[0]), charset))
            for (String line; (line = reader.readLine()) != null;) {
                writer.append(line).append(CRLF)
            }
        }
        catch(Exception e)  {
            e.printStackTrace()
        }
        finally {
            if (reader != null) try { reader.close(); } catch (IOException logOrIgnore) {}
        }
        writer.flush();
        writer.append("--" + boundary + "--").append(CRLF)
    } 
    finally {
        if (writer != null) writer.close();
    }
    InputStream response = connection.getInputStream()
    def xmlString=response.getText()
    xmlString
}

然后在控制台上我得到了

<德尔> http://abhishek157:10070/project/create.action
完成

但它根本没有命中 http://abhishek157:10070/project/create.action
有帮助吗？

更多更新

真正的请求(从 html 表单工作，我从网络浏览器中选择文件)

-----------------------------7dcf4d30e8a
Content-Disposition: form-data; name="sessiontoken"

4611685684744086913
-----------------------------7dcf4d30e8a
Content-Disposition: form-data; name="cfgname"

sadf
-----------------------------7dcf4d30e8a
Content-Disposition: form-data; name="cfgdesc"

sadf
-----------------------------7dcf4d30e8a
Content-Disposition: form-data; name="cfgenv"

Production
-----------------------------7dcf4d30e8a
Content-Disposition: form-data; name="cfgfile"; filename="C:\Simon\xmls\agentind.xml"
Content-Type: text/xml

<?xml version="1.0" encoding="UTF-8"?> and so on...

根据 fiddler 中的实际请求匹配后更新了 params 部分。参见 createConfiguration 函数

获取异常(从 servlet 调用 create.action 时)

注意:我在发送create.action中的参数之前检查了servlet，都是有效的

java.lang.NumberFormatException: null 

服务器中没有读取任何参数，所有参数都以 null 的形式出现。问题出在哪儿。请帮忙。

Answer 1

在更新后的代码中，您忘记调用 connection.getInputStream(); 来实际发送 HTTP 请求(并检索 HTTP 响应)。