我想编写一个简单的程序，通过调用gss-api来实现客户端和服务器之间的安全通信。我试着这样：
mgr = GSSManager.getInstance();
krb5Mechanism = new Oid("1.2.840.113554.1.2.2");
krb5PrincipalNameType = new Oid("1.2.840.113554.1.2.2.1");
serviceName = mgr.createName(serviceNameStr, krb5PrincipalNameType);
cred = mgr.createCredential(serviceName, GSSCredential.INDEFINITE_LIFETIME, krb5Mechanism, GSSCredential.ACCEPT_ONLY);
但是在创建GSSCredential时我得到了GSSException。
GSSException: No valid credentials provided (Mechanism level: Failed to find any Kerberos credentails)
at sun.security.jgss.krb5.Krb5AcceptCredential.getInstance(Unknown Source)
at sun.security.jgss.krb5.Krb5MechFactory.getCredentialElement(Unknown Source)
at sun.security.jgss.GSSManagerImpl.getCredentialElement(Unknown Source)
at sun.security.jgss.GSSCredentialImpl.add(Unknown Source)
at sun.security.jgss.GSSCredentialImpl.<init>(Unknown Source)
at sun.security.jgss.GSSManagerImpl.createCredential(Unknown Source)
at com.juan.gssapi.SimpleGSSAPIServer.loop(SimpleGSSAPIServer.java:55)
at com.juan.gssapi.SimpleGSSAPIServer.main(SimpleGSSAPIServer.java:36)
有人知道原因吗？