title: How to resolve Java UnknownHostKey, while using JSch SFTP library?
body: <p>I'm running a java program where I transfer a file from one folder to another, using Java SFTP. The problem I'm having is that  I'm getting the following error in  my Java SFTP (using JSch) :</p>
  
  <blockquote>
    <p>C:\Oracle\Middleware\Oracle_Home\oracle_common\jdk\bin\javaw.exe
    -server -classpath C:\JDeveloper\mywork\Java_Hello_World.adf;C:\JDeveloper\mywork\Java_Hello_World\Client\classes;C:\Users\ADMIN\Downloads\jsch-0.1.53.jar
    -Djavax.net.ssl.trustStore=C:\Users\IBM_AD~1\AppData\Local\Temp\trustStore5840796204189742395.jks
    FileTransfer com.jcraft.jsch.JSchException: UnknownHostKey: 127.0.0.1.
    RSA key fingerprint is a2:39:3f:44:88:e9:1f:d7:d1:71:f4:85:98:fb:90:dc
      at com.jcraft.jsch.Session.checkHost(Session.java:797)  at
    com.jcraft.jsch.Session.connect(Session.java:342)     at
    com.jcraft.jsch.Session.connect(Session.java:183)     at
    FileTransfer.main(FileTransfer.java:33) Process exited with exit code
    0.</p>
  </blockquote>
  
  <p>The following is my code so far:</p>
  
  <pre><code>FileTransfer fileTransfer = new FileTransfer();              
  
  JSch jsch = new JSch();
  
  try {
  
      String host = "127.0.0.1";
      int port = 22;
  
      String user = "user";
      Session session = jsch.getSession(user, host, port);      
      session = jsch.getSession("username", "127.0.0.1", 22);
      session.connect();  // bug here , java.net.ConnectException
  
      ChannelSftp sftp = null;
      sftp = (ChannelSftp)session.openChannel("sftp") ; //channel;
  
      //extra config code
      java.util.Properties config = new java.util.Properties(); 
      config.put("StrictHostKeyChecking", "no");
      session.setConfig(config);
      // end extra config code
  
      sftp.rename("C:\\Users\\ADMIN\\Desktop\\Work\\ConnectOne_Bancorp\\Java_Work\\SFTP_1\\house.bmp", "C:\\Users\\ADMIN\\Desktop\\Work\\ConnectOne_Bancorp\\Java_Work\\SFTP_2\\house.bmp");  
      session.disconnect();
  
  } catch (JSchException e) {
      e.printStackTrace();  
  } catch (SftpException e) {
      e.printStackTrace();
  } //end-catch
  </code></pre>
  
  <p>My Cygwin is set up, and I checked (with <code>netstat -a -b</code> ) that it's running.</p>