這次帶給大家使用AJAX非同步校驗使用者名稱是否存在，使用AJAX非同步校驗使用者名稱是否存在的注意事項有哪些，以下就是實戰案例，一起來看一下。
使用AJAX完成使用者名稱是否存在非同步校驗:
1.事件觸發:
* onblur
2.編寫AJAX程式碼:
* 項Action中提交:傳遞username參數
3.寫Action
##* 接收username :模型驅動接收.4.* 寫實體類別
* User* User.hbm.xml*配置到spring中.5.寫DAO
* 繼承HibernateDaoSupport##* 在設定中註入sessionFactory
6.寫Service:* 注入UserDao
* 事務管理:
核心程式碼實作：
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;
}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='red'>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='green'>用户名可以使用</font>");
}
return NONE;
}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);
}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;
}<?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>相信看了本文案例你已經掌握了方法，更多精彩請關注php中文網其它相關文章！
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