tomcat表单身份验证后，我想获取用户登录名吗？

Question

我写了一个Java表单身份验证代码。成功登录后，我想在会话中设置用户名，以便我可以进行一些查询，或者是否有任何其他方法来获取在表单身份验证中使用的用户名

Web.xml

            <?xml version="1.0" encoding="UTF-8"?>
        <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
          <display-name>TicketingTool</display-name>
          <welcome-file-list>
            <welcome-file>request.html</welcome-file>
          </welcome-file-list>

          <security-constraint>
            <web-resource-collection>
              <web-resource-name>Timesheets</web-resource-name>
              <url-pattern>/*</url-pattern>
            </web-resource-collection>
            <auth-constraint>
               <role-name>user</role-name>
            </auth-constraint>
          </security-constraint>

          <login-config>
          <auth-method>FORM</auth-method>
                 <form-login-config>
                          <form-login-page>/login.html</form-login-page>
                         <form-error-page>/login.html</form-error-page>
                  </form-login-config>
          </login-config> <security-role>
            <role-name>user</role-name>
          </security-role>
        </web-app>

login.page

  <form class="modal-content animate" method="POST" action="j_security_check">

  <label for="psw"><b>Username</b></label>
  <input type="text" placeholder="Enter Username" name="j_username" required></br>

  <label for="psw"><b>Password</b></label>
  <input type="password" placeholder="Enter Password" name="j_password" required>

   <button type="submit">Login</button>
  </div>

Server.xml

<Realm className="org.apache.catalina.realm.LockOutRealm">  <Realm className="org.apache.catalina.realm.JDBCRealm" connectionName="******" connectionPassword="*******" connectionURL="jdbc:postgresql://localhost:5432/postgres" debug="99" digest="MD5" driverName="org.postgresql.Driver" roleNameCol="role" userCredCol="password" userNameCol="username" userRoleTable="user_roles" userTable="users"/>   </Realm>