Use struts2+Ajax+jquery to verify whether the username has been registered_jquery

Recommended reading: JQuery+Ajax+Struts2+Hibernate framework integration to achieve complete login registration

Regarding the user registration requirements in the user module, it is usually necessary to verify whether the user name has been registered. I just wrote this requirement today and posted the detailed code and problems encountered. When using struts2+ajax , usually we will return json type data, but like the above example, we only hope to return a 1 and 0 to facilitate subsequent judgment. There is no need to return the json type, just return a text string.

regist.jsp (only the <script> part is provided here): </script>

<script type="text/javascript">
$(function() {
$("#userNiName").blur(function() {
var val = $(this).val();
val = $.trim(val);
var $this = $(this);
if (val != "") {
//把当前节点后面的所有 font 兄弟节点删除
$this.nextAll("font").remove();
var url = "user_checkName";
var args = {
"userNiName" : val,
"time" : new Date()
};
$.post(url, args, function(data) {
//表示可用
if (data == "1") {
$this.after("<font color='green'>用户名可用!</font>");
}
//不可用
else if (data == "0") {
$this.after("<font color='red'>用户名已被注册!</font>");
}
//服务器错误
else {
alert("服务器错误!");
}
});
} else {
$(this).val("");
$this.focus();
}
});
})
</script> 

Here I use the Jquery.post(url,args,function(data){..}) function to submit an ajax request to the specified url, and carry the parameters args, and finally use a callback function to process the request and return the result data.

UserAction:

public class UserAction extends ActionSupport implements ModelDriven<User>{
private User user=new User();
private UserService userService;
private InputStream inputStream;
public InputStream getInputStream() {
return inputStream;
}
//检验用户昵称是否存在
public String checkName() throws UnsupportedEncodingException{
System.out.println("进入ajax检验");
String userNiName=user.getUserNiName();
if(userService.findUserByName(userNiName)==null){
inputStream=new ByteArrayInputStream("1".getBytes("UTF-8"));
}else{
inputStream=new ByteArrayInputStream("0".getBytes("UTF-8"));
}
return "ajax_succ";
}
@Override
public User getModel() {
return user;
}
public void setUserService(UserService userService) {
this.userService = userService;
}
} 

Note: Here I use the ModelDriven method to obtain form data, and when using ajax, a userNiName (nickname) is directly passed over, so I added a private string variable userNiName in UserAction and set set method. As a result, the value could not be passed, and a null was passed, so I deleted the private variable and then used user.getUserNiName() to get it directly. Remember.

UserService(omitted).

User class (omitted).

UserDao:

package com.wang.shop.user.dao;
import java.util.List;

import org.springframework.orm.hibernate4.support.HibernateDaoSupport;
import com.wang.shop.user.entity.User;
public class UserDao extends HibernateDaoSupport{
/**
* 通过用户昵称查询User
* @param userNiName
* @return
*/
public User findUserByName(String userNiName){
List<User> list = (List<User>) this.getHibernateTemplate().find("select u from User u where u.userNiName=&#63;", userNiName);
if(list!=null&&list.size()>0){
System.out.println("list:"+list.get(0));
return list.get(0);
}
return null;
}
}

struts.xml:

<&#63;xml version="1.0" encoding="UTF-8" &#63;>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
"http://struts.apache.org/dtds/struts-2.3.dtd">
<struts>
<package name="shop" namespace="/" extends="struts-default">
<!-- UserAction -->
<action name="user_*" class="userAction" method="{1}">
<result name="regist_succ">/WEB-INF/jspForUser/login.jsp</result>
<result type="stream" name="ajax_succ">
<param name="contentType">text/html</param>
<param name="inputStream">inputStream</param>
</result>
</action>
</package>
</struts> 

Note that in the result tag, type="stream".

Finally, by the way, I am used to using output statements when debugging, but every time I add an output statement, I need to restart Tomcat, which is very annoying. So I referred to the online method and put conf->server in the Tmocat installation directory. By adding the following code under the tag in .xml, you can modify the class (minor modifications) without restarting the server:

<!--docBase就是你的项目工程所在的全路径,path就是写你的项目名,reloadable="true",可以自动重新加载修改过的class文件-->
<Context debug="0" docBase="D:\Tomcat 7.0\webapps\SSH_shop01" path="/SSH_shop01" reloadable="true" /> 

It is important to note that after uninstalling the project in Tomcat, you must come back and delete this label.

The editor will introduce you to the knowledge of using struts2+Ajax+jquery to verify whether the user name has been registered. I hope it will be helpful to you!