Eine Zeile zum Verständnis der Ursachen und Folgen der SSH-Anmeldung

<form id=<span class="hljs-string">"loginForm"</span> action=<span class="hljs-string">"<span class="hljs-variable">${ pageContext.request.contextPath }</span>/user_login.action"</span>  method=<span class="hljs-string">"post"</span> novalidate=<span class="hljs-string">"novalidate"</span>>

<action <span class="hljs-property">name</span>=<span class="hljs-string">"user_*"</span> <span class="hljs-type">class</span>=<span class="hljs-string">"userAction"</span> method=<span class="hljs-string">"{1}"</span>>
<<span class="hljs-constant">result</span> <span class="hljs-property">name</span>=<span class="hljs-string">"login"</span>>/WEB-INF/jsp/login.jsp</<span class="hljs-constant">result</span>>

<span class="hljs-keyword">public</span> String <span class="hljs-title">login</span>(){
      User existUser = userService.login(user);
      <span class="hljs-comment">//      判断返回会来的数据是否为空</span>
      <span class="hljs-keyword">if</span>(existUser == <span class="hljs-keyword">null</span>){
          <span class="hljs-keyword">this</span>.addActionError(<span class="hljs-string">"登录失败：用户名或者密码或用户没有激活"</span>);
          <span class="hljs-keyword">return</span> LOGIN;
      }<span class="hljs-keyword">else</span>{
        <span class="hljs-comment">//保存到共享变量中  </span>
         ServletActionContext.getRequest().getSession().setAttribute(<span class="hljs-string">"existUser"</span>, existUser);
        <span class="hljs-comment">// 页面跳转</span>
         <span class="hljs-keyword">return</span> <span class="hljs-string">"loginSuccess"</span>;
      }   
  }

<span class="hljs-javadoc">/**
    *  登录功能
    */</span> 

    <span class="hljs-comment">//用户登录的方法</span>
    <span class="hljs-keyword">public</span> User <span class="hljs-title">login</span>(User user) {
        <span class="hljs-keyword">return</span> userDao.login(user);
}

 <span class="hljs-javadoc">/**
 *  登录功能
 */</span> 
   <span class="hljs-keyword">public</span>  User <span class="hljs-title">login</span>(User user) {
      String hql = <span class="hljs-string">"from User where username = ? and password = ? and state = ?"</span>;
      List<User> list = <span class="hljs-keyword">this</span>.getHibernateTemplate().find(hql,user.getUsername(),user.getPassword(),<span class="hljs-number">1</span>);
        <span class="hljs-keyword">if</span>(list != <span class="hljs-keyword">null</span> && list.size() > <span class="hljs-number">0</span>){
            <span class="hljs-keyword">return</span> list.get(<span class="hljs-number">0</span>);
        }
        <span class="hljs-keyword">return</span> <span class="hljs-keyword">null</span>;
   }