SSHオンラインモールはajaxを使用してユーザー名の非同期認証を完了します

<span style="font-size:18px;">function checkUsername() { 
    //获取文本框值: 
    var username = document.getElementById("username").value; 
    //1、创建异步交互对象 
    var xhr = createXmlHttp(); 
    //2、设置监听 
    xhr.onreadystatechange = function() { 
      if (xhr.readyState == 4) { 
        if (xhr.status == 200) { 
          document.getElementById("span1").innerHTML = xhr.responseText; 
        } 
      } 
    } 
    //3、打开连接 
    xhr.open("GET", 
        "${pageContext.request.contextPath}/user_findByName.action?time=" 
            + new Date().getTime() + "&username=", true) 
    //4、发送 
    xhr.send(null); 
  } 
  function createXmlHttp() { 
    var xmlHttp; 
    try { 
      xmlHttp = new XMLHttpRequest(); 
    } 
    catch (e) { 
      try { 
        xmlHttp = new ActiveXObject("Msxml2.XMLHTTP"); 
      } 
       catch (e) { 
        try { 
          xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); 
        } catch (e) {} 
      } 
    } 
    return xmlHttp; 
  } 
</span>

<span style="font-size:18px;">package cn.itcast.shop.user.vo; 
public class User { 
  private Integer uid; 
  private String username; 
  private String password; 
  private String name; 
  private String email; 
  private String phone; 
  private String addr; 
  private Integer state; 
  private String code; 
  public Integer getUid() { 
    return uid; 
  } 
  public void setUid(Integer uid) { 
    this.uid = uid; 
  } 
  public String getUsername() { 
    return username; 
  } 
  public void setUsername(String username) { 
    this.username = username; 
  } 
  public String getPassword() { 
    return password; 
  } 
  public void setPassword(String password) { 
    this.password = password; 
  } 
  public String getName() { 
    return name; 
  } 
  public void setName(String name) { 
    this.name = name; 
  } 
  public String getEmail() { 
    return email; 
  } 
  public void setEmail(String email) { 
    this.email = email; 
  } 
  public String getPhone() { 
    return phone; 
  } 
  public void setPhone(String phone) { 
    this.phone = phone; 
  } 
  public String getAddr() { 
    return addr; 
  } 
  public void setAddr(String addr) { 
    this.addr = addr; 
  } 
  public Integer getState() { 
    return state; 
  } 
  public void setState(Integer state) { 
    this.state = state; 
  } 
  public String getCode() { 
    return code; 
  } 
  public void setCode(String code) { 
    this.code = code; 
  } 
}</span>

<span style="font-size:18px;"><!-- Service的配置 =========================== --> 
  <bean id="userService" class="cn.itcast.shop.user.service.UserService"> 
    <property name="userDao" ref="userDao"/> 
  </bean>  
  <!-- UserDao的配置 =========================== --> 
   <bean id="userDao" class="cn.itcast.shop.user.dao.UserDao"> 
    <property name="sessionFactory" ref="sessionFactory"></property> 
</bean> </span>

<span style="font-size:18px;">package cn.itcast.shop.user.dao; 
import org.springframework.orm.hibernate3.support.HibernateDaoSupport; 
import java.util.List; 
import cn.itcast.shop.user.vo.User; 
/** 
 * 用户模块持久层代码 
 * @author Flower 
 * 
 */ 
public class UserDao extends HibernateDaoSupport { 
  //按名次查询是否有该用户 
  public User findByUsername (String username){ 
    String hql ="from User where username= ?"; 
    List <User> list=this.getHibernateTemplate().find(hql,username); 
    if(list !=null && list.size() > 0){ 
      return list.get(0); 
    } 
     return null; 
    } 
} 
</span>

<span style="font-size:18px;">package cn.itcast.shop.user.service; 
import org.springframework.transaction.annotation.Transactional; 
import cn.itcast.shop.user.dao.UserDao; 
import cn.itcast.shop.user.vo.User; 
/** 
 * 用户模块业务层代码 
 * @author Flower 
 * 
 */ 
@Transactional 
public class UserService { 
  //注入UserDao 
  private UserDao userDao; 
  public void setUserDao(UserDao userDao){ 
    this.userDao =userDao; 
  } 
  //按用户名查询用户的方法 
  public User findByUsername (String username){ 
    return userDao.findByUsername(username); 
  } 
} 
</span>

<span style="font-size:18px;"><?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE hibernate-mapping PUBLIC  
  "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
  "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> 
  <hibernate-mapping> 
    <class name="cn.itcast.shop.user.vo.User" table="user"> 
      <id name="uid"> 
        <generator class="native"/> 
      </id> 
      <property name="username"/> 
      <property name="password"/> 
      <property name="name"/> 
      <property name="email"/> 
      <property name="phone"/> 
      <property name="addr"/> 
      <property name="state"/> 
      <property name="code"/> 
    </class> 
  </hibernate-mapping></span>