让我看看能否解释一下。前端为我提供了一个电子表格，我需要通过api调用将其传递到我的中央服务器来进行处理。我使用以下代码来提取电子表格并创建我的工作簿，
Part spreadsheet = request.getPart(SPREADSHEET);
Workbook workbook = WorkbookFactory.create(spreadsheet.getInputStream());
其中'request'是传入的HttpServletRequest对象。我知道它可以工作，我可以操作电子表格，但我需要将它传递给我的其他服务器进行处理，我无法弄清楚如何做到这一点。这是我到目前为止所拥有的。
@Path("/uploadSpreadsheet")
@POST
public String uploadSpreadsheet(@Context final HttpServletRequest request,@Context final HttpHeaders httpHeaders) throws IOException, ServletException, InvalidFormatException, JSONException {
return uploadUtil(request, "rest/memberService/uploadSpreadsheet");
}
这是我无法做到的工具。
private String uploadUtil(HttpServletRequest request, String serviceUrl) throws MalformedURLException, ProtocolException, IOException, ServletException {
String baseUrl = "http://localhost:8084/centralservices/";
String urlString = baseUrl.concat(serviceUrl);
URL url = new URL(urlString);
String boundary = "===" + System.currentTimeMillis() + "===";
HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
httpCon.setDoOutput(true);
httpCon.setRequestMethod("POST");
httpCon.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
httpCon.setRequestProperty("Key", "SOMEKEYHERE");
httpCon.setRequestProperty("clientAddress", request.getRemoteAddr());
//I know this is wrong but I'm not sure what goes here:
httpCon.setRequestProperty("file", request.getPart(SPREADSHEET));
int responseCode;
StringBuilder resp = new StringBuilder();
BufferedReader in = null;
try {
in = new BufferedReader(new InputStreamReader(httpCon.getInputStream(), "UTF-8"));
String inputLine;
while ((inputLine = in.readLine()) != null) {
resp.append(inputLine);
}
} finally {
if (in != null) {
in.close();
}
httpCon.disconnect();
}
return resp.toString();
}
希望这是有道理的。我的意思是我真正需要做的就是将请求相同（将所有formpart和所有内容）转移到不同的URL。一旦它到达那里我没有处理它的问题。如果我对某些事情不清楚，请告诉我。我对这些东西很新。我们已经有一个休息实用程序，我一直用于其他所有东西，但它不适用于这种情况，所以我需要创建一个新的。
答案 0 :(得分：0)
如果您使用的是Servlet-Api 3.0，则以下方法将为您提供如何读取流并将流写回后续URL的信息。
http://balusc.omnifaces.org/2009/12/uploading-files-in-servlet-30.html
从上面的代码中，获得Part后，将获取的文件/工作簿转换为bytebuffer，然后将其写入Output stream。
connection.getOutputStream（）写（filebuff）;
因为在这种情况下添加到请求属性将无济于事。
由于 Maruthi
答案 1 :(得分：0)
我认为多部分请求中缺少很多东西。看到这个链接 Sending files using POST with HttpURLConnection。
使用某些API为您完成此操作可能更好，最简单的可能是apache httpclient
请参阅this SO post
中的示例用法如果您确实需要使用URLConnection，那么您可以使用此multipart utility from codejava.net
我在这里发布代码以备份，以防原始链接出现故障。
<强> MultipartUtility
package net.codejava.networking;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.List;
/**
* This utility class provides an abstraction layer for sending multipart HTTP
* POST requests to a web server.
* @author www.codejava.net
*
*/
public class MultipartUtility {
private final String boundary;
private static final String LINE_FEED = "\r\n";
private HttpURLConnection httpConn;
private String charset;
private OutputStream outputStream;
private PrintWriter writer;
/**
* This constructor initializes a new HTTP POST request with content type
* is set to multipart/form-data
* @param requestURL
* @param charset
* @throws IOException
*/
public MultipartUtility(String requestURL, String charset)
throws IOException {
this.charset = charset;
// creates a unique boundary based on time stamp
boundary = "===" + System.currentTimeMillis() + "===";
URL url = new URL(requestURL);
httpConn = (HttpURLConnection) url.openConnection();
httpConn.setUseCaches(false);
httpConn.setDoOutput(true); // indicates POST method
httpConn.setDoInput(true);
httpConn.setRequestProperty("Content-Type",
"multipart/form-data; boundary=" + boundary);
httpConn.setRequestProperty("User-Agent", "CodeJava Agent");
/*Following line has no significance for the task this utility performs*/
/*httpConn.setRequestProperty("Test", "Bonjour");*/
outputStream = httpConn.getOutputStream();
writer = new PrintWriter(new OutputStreamWriter(outputStream, charset),
true);
}
/**
* Adds a form field to the request
* @param name field name
* @param value field value
*/
public void addFormField(String name, String value) {
writer.append("--" + boundary).append(LINE_FEED);
writer.append("Content-Disposition: form-data; name=\"" + name + "\"")
.append(LINE_FEED);
writer.append("Content-Type: text/plain; charset=" + charset).append(
LINE_FEED);
writer.append(LINE_FEED);
writer.append(value).append(LINE_FEED);
writer.flush();
}
/**
* Adds a upload file section to the request
* @param fieldName name attribute in <input type="file" name="..." />
* @param uploadFile a File to be uploaded
* @throws IOException
*/
public void addFilePart(String fieldName, File uploadFile)
throws IOException {
String fileName = uploadFile.getName();
writer.append("--" + boundary).append(LINE_FEED);
writer.append(
"Content-Disposition: form-data; name=\"" + fieldName
+ "\"; filename=\"" + fileName + "\"")
.append(LINE_FEED);
writer.append(
"Content-Type: "
+ URLConnection.guessContentTypeFromName(fileName))
.append(LINE_FEED);
writer.append("Content-Transfer-Encoding: binary").append(LINE_FEED);
writer.append(LINE_FEED);
writer.flush();
FileInputStream inputStream = new FileInputStream(uploadFile);
byte[] buffer = new byte[4096];
int bytesRead = -1;
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
outputStream.flush();
inputStream.close();
writer.append(LINE_FEED);
writer.flush();
}
/**
* Adds a header field to the request.
* @param name - name of the header field
* @param value - value of the header field
*/
public void addHeaderField(String name, String value) {
writer.append(name + ": " + value).append(LINE_FEED);
writer.flush();
}
/**
* Completes the request and receives response from the server.
* @return a list of Strings as response in case the server returned
* status OK, otherwise an exception is thrown.
* @throws IOException
*/
public List<String> finish() throws IOException {
List<String> response = new ArrayList<String>();
writer.append(LINE_FEED).flush();
writer.append("--" + boundary + "--").append(LINE_FEED);
writer.close();
// checks server's status code first
int status = httpConn.getResponseCode();
if (status == HttpURLConnection.HTTP_OK) {
BufferedReader reader = new BufferedReader(new InputStreamReader(
httpConn.getInputStream()));
String line = null;
while ((line = reader.readLine()) != null) {
response.add(line);
}
reader.close();
httpConn.disconnect();
} else {
throw new IOException("Server returned non-OK status: " + status);
}
return response;
}
}
测试计划
package net.codejava.networking;
import java.io.File;
import java.io.IOException;
import java.util.List;
/**
* This program demonstrates a usage of the MultipartUtility class.
* @author www.codejava.net
*
*/
public class MultipartFileUploader {
public static void main(String[] args) {
String charset = "UTF-8";
File uploadFile1 = new File("e:/Test/PIC1.JPG");
File uploadFile2 = new File("e:/Test/PIC2.JPG");
String requestURL = "http://localhost:8080/FileUploadSpringMVC/uploadFile.do";
try {
MultipartUtility multipart = new MultipartUtility(requestURL, charset);
multipart.addHeaderField("User-Agent", "CodeJava");
multipart.addHeaderField("Test-Header", "Header-Value");
multipart.addFormField("description", "Cool Pictures");
multipart.addFormField("keywords", "Java,upload,Spring");
multipart.addFilePart("fileUpload", uploadFile1);
multipart.addFilePart("fileUpload", uploadFile2);
List<String> response = multipart.finish();
System.out.println("SERVER REPLIED:");
for (String line : response) {
System.out.println(line);
}
} catch (IOException ex) {
System.err.println(ex);
}
}
}
答案 2 :(得分：0)
我对所提出的一些选项太不熟悉所以我只是将电子表格转换为json字符串并将其与现有的rest实用程序一起发送。