Java服务器返回了HTTP响应代码：401

我编写了一个java程序，通过http基本身份验证来执行http post请求 但它总是显示错误401。我的用户名和密码正确，可以登录网站。我不知道哪里错了

 import java.io.BufferedReader;
 import java.io.DataOutputStream;
 import java.io.InputStreamReader;
 import java.net.HttpURLConnection;
 import java.net.URL;
 import sun.misc.*;

 import javax.net.ssl.HttpsURLConnection;
 import org.apache.commons.codec.*;

 @SuppressWarnings("unused")
 public class hello {

/**
 * @param args
 */
private final String USER_AGENT = "Mozilla/5.0";
public static void main(String[] args) throws Exception {
    // TODO Auto-generated method stub
    hello http = new hello();


    //System.out.println("Testing 1 - Send Http GET request");
    //http.sendGet();

    System.out.println("\nTesting 2 - Send Http POST request");
    http.sendPost();
}

@SuppressWarnings("unused")
private void sendPost() throws Exception {

    String url = "https://mds.datacite.org/doi";
    URL obj = new URL(url);
    HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();
    String userPassword= "username:password";
    String encoding = new String(org.apache.commons.codec.binary.Base64.encodeBase64(org.apache.commons.codec.binary.StringUtils.getBytesUtf8(userPassword)));
    System.out.println(encoding);


    //add reuqest header
    con.setRequestMethod("POST");
    con.setRequestProperty("Content-Type", "text/plain");
    con.setRequestProperty("charset", "UTF-8");
    con.setRequestProperty("Authorization","Basic"+encoding);


    String urlParameters = "doi=xxxxxx&url=http://xxxxx/dataset/1xxx099";

    // Send post request
    con.setDoOutput(true);
    DataOutputStream wr = new DataOutputStream(con.getOutputStream());
    wr.writeBytes(urlParameters);
    wr.flush();
    wr.close();

    int responseCode = con.getResponseCode();
    System.out.println("\nSending 'POST' request to URL : " + url);
    System.out.println("Post parameters : " + urlParameters);
    System.out.println("Response Code : " + responseCode);

    BufferedReader in = new BufferedReader(
            new InputStreamReader(con.getInputStream()));
    String inputLine;
    StringBuffer response = new StringBuffer();

    while ((inputLine = in.readLine()) != null) {
        response.append(inputLine);
    }
    in.close();

    //print result
    System.out.println(response.toString());

}

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401==未经授权，这意味着您的用户名/密码组合不正确

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您需要在授权标题中的“Basic”后面加一个空格，表示您的用户名/密码组合不正确

您需要在授权标题中的“Basic”后面加一个空格