具有恢复功能的

Question

我有一个负责上传文件的PHP服务器，以及一个将上传文件的android应用程序。我已经尝试了很多代码来执行此操作，但在互联网等任何中断后它无法支持恢复功能 DIS-连接。最后我发现了一些与javascript一起使用的PHP代码，我试着在java中创建一个代码来传递php。 PHP代码使用file_get_contents("php://input");，但我不明白这个方法使用的协议，所以我传达并发送文件到服务器，这是我的java代码。

package fileuploadingclient;

import java.io.File;
import java.io.IOException;
import java.util.List;

public class FileUploadingClient {
public static void main(String[] args) {

    String charset = "UTF-8";
    File uploadFile = new File("path/to/file.jpg");
    String requestURL = "http://path/to/server.php?fnc=upl";

    try {
        MultipartUtility multipart = new MultipartUtility(requestURL, charset, uploadFile);

        multipart.addHeaderField("User-Agent", "CodeJava");
        multipart.addHeaderField("Test-Header", "Header-Value");

        multipart.addFormField("description", "Cool Pictures");
        multipart.addFormField("keywords", "Java,upload,Spring");

        multipart.addFilePart("uploaded_file", uploadFile);

        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);
    }        

}

}

MultipartUtility.java

package fileuploadingclient;

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;

 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, File uploadFile1)
        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");
    httpConn.setRequestProperty("Test", "Bonjour");
    httpConn.setRequestProperty("X-File-Name", uploadFile1.getName());
    httpConn.setRequestProperty("X-File-Size", uploadFile1.length()+"");


    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();
    int offset = 0;
    System.out.println("File Length : "+uploadFile.length());



    FileInputStream inputStream = new FileInputStream(uploadFile);
    byte[] buffer = new byte[1024];
    int bytesRead = -1;
    while ((bytesRead = inputStream.read(buffer,offset,buffer.length - offset)) != -1) {
        outputStream.write(buffer, offset, bytesRead);
        break;
    }
    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;
}    
}

PHP代码：我已从Github下载

感谢。