Spring Security authentication ignoring password - spring

Question

In my project I have implemented Spring Security. It's checking whether username and password is correct or not. I want to authenticate only username but not password. How can I achieve this?
public UserDetails loadUserByUsername(String username) {
if (lan == null) {
// loadPasswordRules();
}
List<UserDetails> users = loadUsersByUsername(username);
if (users.size() == 0) {
throw new AuthenticationServiceException("Username " + username + " is invalid ");
}
UserDetails user = users.get(0); // contains no IRole[]
/** Raising exception since start and expiry of user is not valid. */
/** Raising exception since start and expiry of user is not valid. */
Date todayDate = new Date();
if ( !((todayDate).after(((User) user).getStartDate()) && (todayDate).before(((User) user).getExpiryDate())) ) {
throw new AuthenticationServiceException("User " + username + " account is expired.");
/* throw new LockedException("User " + username + " account is expired.");
throw new UsernameNotFoundException("User {" + username + "} account is expired."); SPRING_SECURITY_LAST_EXCEPTION.message */
}
/*if ( ((User) user).getLastSuccessLogin() != null) {
Calendar newDate = Calendar.getInstance();
newDate.setTime( todayDate );
newDate.add(Calendar.DAY_OF_YEAR, - lan.intValue());
Calendar oldDate = Calendar.getInstance();
oldDate.setTime( ((User) user).getLastSuccessLogin() );
if (newDate.after(oldDate)) {
lockUserAccount(username);
throw new AuthenticationServiceException("User " + username + " account is expired.");
}
}*/
Set<IRole> dbAuthsSet = new HashSet<IRole>();
if (enableAuthorities) {
dbAuthsSet.addAll(loadUserAuthorities(user.getUsername()));
}
List<IRole> dbAuths = new ArrayList<IRole>(dbAuthsSet);
if (dbAuths.size() == 0) {
throw new AuthenticationServiceException("Username " + username + " has no assigned roles.");
}
((User) user).setRoles(dbAuths);
return user;
}

Answer 1

You should be able to accomplish this creating a custom AuthenticationProvider implementation and configure your AuthenticationManager to use that.

Answer 2

You should create a Custom Filter to due with this. The Filter should extends class AbstractAuthenticationProcessingFilter and return a Custom Authentication object. Then the Authentication Provider will see it and do check only username which is return by the Filter. After completing everything, you must do configure the Filter to Spring Security context to make it works.
You also can see my complete example here : http://phuonghuynh.github.io/java/spring/security/2015/09/06/spring-security-multiple-authentication-providers.html