Home > Backend Development > PHP Tutorial > Detailed example of using AJAX to complete asynchronous verification of user name

Detailed example of using AJAX to complete asynchronous verification of user name

小云云
Release: 2023-03-19 11:56:01
Original
1664 people have browsed it

This article mainly introduces the relevant information on using AJAX to complete asynchronous verification of user names. Friends in need can refer to it. I hope it can help everyone.

Use AJAX to complete asynchronous verification of whether the user name exists:

1. Event triggering:

* onblur

2. Write AJAX code:

* Submit in item Action: pass username parameter

3. Write Action

* to receive username :Model driven reception.

4.* Write entity class

* User

* User.hbm.xml

* Configure into spring.

5. Write DAO

* Inherit HibernateDaoSupport

* Inject sessionFactory

## in the configuration #6. Write Service:

* Inject UserDao

* Transaction management:

Core code implementation:


function checkUsername(){ 
    // 获得文件框值: 
    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="+username,true); 
    // 4.发送 
    xhr.send(null); 
  } 
  function createXmlHttp(){ 
      var xmlHttp; 
      try{ // Firefox, Opera 8.0+, Safari 
        xmlHttp=new XMLHttpRequest(); 
      } 
      catch (e){ 
        try{// Internet Explorer 
           xmlHttp=new ActiveXObject("Msxml2.XMLHTTP"); 
         } 
        catch (e){ 
         try{ 
           xmlHttp=new ActiveXObject("Microsoft.XMLHTTP"); 
         } 
         catch (e){} 
         } 
      } 
      return xmlHttp; 
     }
Copy after login


public String findByName() throws IOException { 
    // 调用Service进行查询: 
    User existUser = userService.findByUsername(user.getUsername()); 
    // 获得response对象,项页面输出: 
    HttpServletResponse response = ServletActionContext.getResponse(); 
    response.setContentType("text/html;charset=UTF-8"); 
    // 判断 
    if (existUser != null) { 
      // 查询到该用户:用户名已经存在 
      response.getWriter().println("<font color=&#39;red&#39;>用户名已经存在</font>"); 
    } else { 
      // 没查询到该用户:用户名可以使用 
      response.getWriter().println("<font color=&#39;green&#39;>用户名可以使用</font>"); 
    } 
    return NONE; 
  }
Copy after login


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); 
  }
Copy after login


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; 
  }
Copy after login


<?xml version="1.0" encoding="UTF-8"?> 
<beans xmlns="http://www.springframework.org/schema/beans" 
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
  xmlns:context="http://www.springframework.org/schema/context" 
  xmlns:aop="http://www.springframework.org/schema/aop" 
  xmlns:tx="http://www.springframework.org/schema/tx" 
  xsi:schemaLocation="http://www.springframework.org/schema/beans  
  http://www.springframework.org/schema/beans/spring-beans.xsd 
  http://www.springframework.org/schema/context 
  http://www.springframework.org/schema/context/spring-context.xsd 
  http://www.springframework.org/schema/aop 
  http://www.springframework.org/schema/aop/spring-aop.xsd 
  http://www.springframework.org/schema/tx  
  http://www.springframework.org/schema/tx/spring-tx.xsd"> 
  <!-- 配置连接池: --> 
  <!-- 引入外部属性文件 --> 
  <context:property-placeholder location="classpath:jdbc.properties"/> 
  <!-- 配置C3P0连接池: --> 
  <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> 
    <property name="driverClass" value="${jdbc.driver}"/> 
    <property name="jdbcUrl" value="${jdbc.url}"/> 
    <property name="user" value="${jdbc.user}"/> 
    <property name="password" value="${jdbc.password}"/> 
  </bean> 
  <!-- Hibernate的相关信息 --> 
  <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean"> 
    <!-- 注入连接池 --> 
    <property name="dataSource" ref="dataSource"/> 
    <!-- 配置Hibernate的其他的属性 --> 
    <property name="hibernateProperties"> 
      <props> 
        <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop> 
        <prop key="hibernate.show_sql">true</prop> 
        <prop key="hibernate.format_sql">true</prop> 
        <prop key="hibernate.connection.autocommit">false</prop> 
        <prop key="hibernate.hbm2ddl.auto">update</prop> 
      </props> 
    </property> 
    <!-- 配置Hibernate的映射文件 --> 
    <property name="mappingResources"> 
      <list> 
        <value>cn/itcast/shop/user/vo/User.hbm.xml</value> 
      </list> 
    </property> 
  </bean> 
  <!-- 事务管理: --> 
  <!-- 事务管理器 --> 
  <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"> 
    <property name="sessionFactory" ref="sessionFactory"/> 
  </bean> 
  <!-- 开启注解事务 --> 
  <tx:annotation-driven transaction-manager="transactionManager"/> 
  <!-- Action的配置 ===========================--> 
  <!-- 首页访问的Action --> 
  <bean id="indexAction" class="cn.itcast.shop.index.action.IndexAction" scope="prototype"> 
  </bean> 
  <!-- 配置验证码Action --> 
  <bean id="checkImgAction" class="cn.itcast.shop.user.action.CheckImgAction" scope="prototype"> 
  </bean> 
  <!-- 用户模块的Action --> 
  <bean id="userAction" class="cn.itcast.shop.user.action.UserAction" scope="prototype"> 
    <!-- 注入Service --> 
    <property name="userService" ref="userService"/> 
  </bean> 
  <!-- Service的配置 ===========================--> 
  <bean id="userService" class="cn.itcast.shop.user.service.UserService"> 
    <property name="userDao" ref="userDao"/> 
  </bean> 
  <!-- Dao的配置 ===========================--> 
  <bean id="userDao" class="cn.itcast.shop.user.dao.UserDao"> 
    <property name="sessionFactory" ref="sessionFactory"/> 
  </bean> 
</beans> 
[html] view plain copy 在CODE上查看代码片派生到我的代码片
<?xml version="1.0" encoding="UTF-8" ?> 
<!DOCTYPE struts PUBLIC 
  "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN" 
  "http://struts.apache.org/dtds/struts-2.3.dtd"> 
<struts> 
  <constant name="struts.devMode" value="false" /> 
  <constant name="struts.enable.DynamicMethodInvocation" value="true"/> 
  <package name="shop" extends="struts-default" namespace="/"> 
    <global-results> 
      <result name="msg">/WEB-INF/jsp/msg.jsp</result> 
    </global-results> 
    <!-- 配置首页访问的Action --> 
    <action name="index" class="indexAction"> 
      <result name="index">/WEB-INF/jsp/index.jsp</result> 
    </action> 
    <!-- 配置用户模块的Action --> 
    <action name="user_*" class="userAction" method="{1}"> 
      <result name="registPage">/WEB-INF/jsp/regist.jsp</result> 
      <result name="input">/WEB-INF/jsp/regist.jsp</result> 
      <result name="loginPage">/WEB-INF/jsp/login.jsp</result> 
      <result name="login">/WEB-INF/jsp/login.jsp</result> 
      <result name="loginSuccess" type="redirectAction">index</result> 
      <result name="quit" type="redirectAction">index</result> 
      <result name="checkcodeFail">/WEB-INF/jsp/regist.jsp</result> 
    </action> 
    <!-- 验证码Action --> 
    <action name="checkImg" class="checkImgAction"></action> 
  </package> 
</struts>
Copy after login

Related recommendations;


Javascript rewrites the asynchronous verification form into a synchronous form_javascript skills

Detailed explanation of the traditional method of javascript to implement asynchronous verification_javascript skills

Examples explain the tradition of ajax implementation of user name verification and the $.post method of jquery

The above is the detailed content of Detailed example of using AJAX to complete asynchronous verification of user name. For more information, please follow other related articles on the PHP Chinese website!

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template