core/src/main/java/org/springframework/security/core/userdetails/jdbc/JdbcDaoImpl.java
protected List<UserDetails> loadUsersByUsername(String username) {
		return getJdbcTemplate().query(this.usersByUsernameQuery,
				new String[] { username }, new RowMapper<UserDetails>() {
					@Override
					public UserDetails mapRow(ResultSet rs, int rowNum)
							throws SQLException {
						String username = rs.getString(1);
						String password = rs.getString(2);
						boolean enabled = rs.getBoolean(3);
						return new User(username, password, enabled, true, true, true,
								AuthorityUtils.NO_AUTHORITIES);
					}

				});
	}
protected List<UserDetails> loadUsersByUsername(String username) {
		return getJdbcTemplate().query(this.usersByUsernameQuery,
				new String[] { username }, new RowMapper<UserDetails>() {
					@Override
					public UserDetails mapRow(ResultSet rs, int rowNum)
							throws SQLException {
						String username = rs.getString(1);
						String password = rs.getString(2);
						boolean enabled = rs.getBoolean(3);
						return new User(username, password, enabled, true, true, true,
								AuthorityUtils.NO_AUTHORITIES);
					}

				});
	}
Executes the SQL <tt>usersByUsernameQuery</tt> and returns a list of UserDetails
objects. There should normally only be one matching user.