AJAX JQUERY STRUTS2.....异步验证用户名-优快云博客

本文介绍了一种在Web应用中解决中文乱码的方法，通过在web.xml中配置统一编码过滤器并设置UTF-8编码，确保从前端到后端的数据传输过程中字符编码的一致性。同时展示了具体的Java代码实现及Struts2框架中的应用实例。

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首先在web.xml加上统一编码过滤器.為的是防止乱码.

<filter>
  <filter-name>Set Character Encoding</filter-name>
  <filter-class>
   com.filter.SetCharacterEncodingFilter
  </filter-class>
  <init-param>
   <param-name>encoding</param-name>
   <param-value>UTF-8</param-value>
  </init-param>
</filter>
<filter-mapping>
  <filter-name>Set Character Encoding</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>

java代码:

/**
*
*/
package com.filter;

/**
* @author
*
*/
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class SetCharacterEncodingFilter implements Filter {

private String charset = "UTF-8";

public void destroy() {
}

public void doFilter(ServletRequest arg0, ServletResponse arg1,
FilterChain arg2) throws IOException, ServletException {
arg0.setCharacterEncoding(charset);
arg1.setCharacterEncoding(charset);
arg2.doFilter(arg0, arg1);
}

public void init(FilterConfig arg0) throws ServletException {
}
}

jsp页面：

javascript:

$(document).ready(function(){
$("#stuid").change(function(){
$.post("userSearchSys.action", {username: $("#stuid").val()} ,function(data){alert(data);});
});
});

绑定onchange事件.

struts2.xml:

  <action name="*Sys" class="com.action.Sys" method="{1}">
   <result type="stream"><param name="username">inputStream</param></result>
  </action>

action:

public String userSearch(){
  StudentDao sDao = new StudentDao();

  try {
  int i =sDao.searchUsername(username);
  HttpServletResponse response = ServletActionContext.getResponse();
  PrintWriter out = response.getWriter();

  response.setCharacterEncoding("UTF-8");
  response.setHeader("Charset","UTF-8");
  response.setHeader("Cache-Control", "no-cache");
  if (i==1){
   out.println("用户名已经存在");
   }
  else {
   out.println("用户名可用");
  }}
  catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  return null;
}