java.io.IOException : Server returned non-OK status: 404

Question

来源:http://www.codejava.net/java-se/networking/upload-files-by-sending-multipart-request-programmatically

为什么它不返回状态？我正在 godaddy 上访问我的文件管理器

MultipartFileUploader.java

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

public class MultipartFileUploader {

public static void main(String[] args) {
    String charset = "UTF-8";
    File uploadFile1 = new File("C:/Users/jimmy/Pictures/Artist/TJ Monterde.jpg");
    File uploadFile2 = new File("C:/Users/jimmy/Pictures/Artist/Mariah Carey.jpg");
    String requestURL = "http://jamthesis.com/images";

    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);
    }
}  }

MultipartUtility.java

 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");
    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;
} }

Answer 1

您尝试访问的请求 URL ( http://jamthesis.com/images ) 不存在。这就是您收到 404 错误的原因。请检查您尝试将文件上传到的 URL。