public void setSystemUsername(String systemUsername) {
        this.systemUsername = systemUsername;
    }
Sets the system username that will be used when creating an LDAP connection used for authorization queries.
The user must have the ability to query for authorization data for any application user.
<p/>
Note that setting this property is not required if the calling LDAP Realm does not perform authorization
checks.

@param systemUsername the system username that will be used when creating an LDAP connection used for
                      authorization queries.
core/src/main/java/org/apache/shiro/realm/ldap/JndiLdapContextFactory.java