使用AJAX完成用户名是否存在异步校验:
1.事件触发:
* onblur
2.编写AJAX代码:
* 项Action中提交:传递username参数
3.编写Action
* 接收username:模型驱动接收.
4.* 编写实体类
* User
* User.hbm.xml
* 配置到spring中.
5.编写DAO
* 继承HibernateDaoSupport
* 在配置中注入sessionFactory
6.编写Service:
* 注入UserDao
* 事务管理:
核心代码实现：
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","${pageContext.request.contextPath}/user_findByName.action?time="+new Date().getTime()+"&username="+username,true); // 4.发送 xhr.send(null); } function createXmlHttp(){ var xmlHttp; try{ // Firefox, Opera 8.0+, Safari xmlHttp=new XMLHttpRequest(); } catch (e){ try{// Internet Explorer xmlHttp=new ActiveXObject("Msxml2.XMLHTTP"); } catch (e){ try{ xmlHttp=new ActiveXObject("Microsoft.XMLHTTP"); } catch (e){} } } return xmlHttp; }
public String findByName() throws IOException { // 调用Service进行查询: User existUser = userService.findByUsername(user.getUsername()); // 获得response对象,项页面输出: HttpServletResponse response = ServletActionContext.getResponse(); response.setContentType("text/html;charset=UTF-8"); // 判断 if (existUser != null) { // 查询到该用户:用户名已经存在 response.getWriter().println("<font color='red'>用户名已经存在</font>"); } else { // 没查询到该用户:用户名可以使用 response.getWriter().println("<font color='green'>用户名可以使用</font>"); } return NONE; }
private UserDao userDao; public void setUserDao(UserDao userDao) { this.userDao = userDao; } // 按用户名查询用户的方法: public User findByUsername(String username){ return userDao.findByUsername(username); }
public User findByUsername(String username){ String hql = "from User where username = ?"; List<User> list = this.getHibernateTemplate().find(hql, username); if(list != null && list.size() > 0){ return list.get(0); } return null; }
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans "> <!-- 配置连接池: --> <!-- 引入外部属性文件 --> <context:property-placeholder location="classpath:jdbc.properties"/> <!-- 配置C3P0连接池: --> <bean> <property value="${jdbc.driver}"/> <property value="${jdbc.url}"/> <property value="${jdbc.user}"/> <property value="${jdbc.password}"/> </bean> <!-- Hibernate的相关信息 --> <bean> <!-- 注入连接池 --> <property ref="dataSource"/> <!-- 配置Hibernate的其他的属性 --> <property> <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> <list> <value>cn/itcast/shop/user/vo/User.hbm.xml</value> </list> </property> </bean> <!-- 事务管理: --> <!-- 事务管理器 --> <bean> <property 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 scope="prototype"> </bean> <!-- 配置验证码Action --> <bean scope="prototype"> </bean> <!-- 用户模块的Action --> <bean scope="prototype"> <!-- 注入Service --> <property ref="userService"/> </bean> <!-- Service的配置 ===========================--> <bean> <property ref="userDao"/> </bean> <!-- Dao的配置 ===========================--> <bean> <property 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 value="false" /> <constant value="true"/> <package extends="struts-default" namespace="https://www.jb51.net/"> <global-results> <result>/WEB-INF/jsp/msg.jsp</result> </global-results> <!-- 配置首页访问的Action --> <action> <result>/WEB-INF/jsp/index.jsp</result> </action> <!-- 配置用户模块的Action --> <action method="{1}"> <result>/WEB-INF/jsp/regist.jsp</result> <result>/WEB-INF/jsp/regist.jsp</result> <result>/WEB-INF/jsp/login.jsp</result> <result>/WEB-INF/jsp/login.jsp</result> <result type="redirectAction">index</result> <result type="redirectAction">index</result> <result>/WEB-INF/jsp/regist.jsp</result> </action> <!-- 验证码Action --> <action></action> </package> </struts>