Ajax:

function veryfy(){
 //乱码问题解决:
  //1.页面端发送的数据采用encodeURI,encodeURI($("#username").val()),服务器端采用new String(str.getBytes("iso8859-1","utf-8"));
 //2.页面端发送的数据采用两次encodeURI,encodeURI(encodeURI($("#username").val())),服务器端URLDecoder.decode(str,"utf-8");
 $.get("AjaxSeverlet?name=" + encodeURI($("#username").val()), null, function(data){
  $("#msg").html(data);
 });
 
}

服务器端:

public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
    request.setCharacterEncoding("gb2312");   
    response.setHeader("charset","gb2312");  //设置返回页面的头 meta 信息
    response.setContentType("text/html;charset=gb2312");  //设置输出的文档类型
   // 以上内容在PrintWriter 声明前设置,杜绝乱码
    
          PrintWriter out=response.getWriter(); 
       
          //接收参数实例:(Ajax页面端到服务器端)
          String s = request.getParameter("name");
          s = new String(s.getBytes("iso-8859-1"), "utf-8");  
          System.out.println(s);
          
          //服务器端到页面端:
         // out.print("Ajax乱码解决"); //直接输出中文 
          
          /*
           *从数据库中取中文数据
           */ 
          SqlTools st = new SqlTools();
          ResultSet rs = st.getResultSet("select seller from orders where orderid = 1");
          
         
          String dbs = "";
          try {
   if(rs.next()) {
      dbs = rs.getString("seller");
     } 
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  out.print(dbs); 
 }

方案二:

方案一有时候确实不稳定,只需要在页面端两次encodeURI,然后在服务器端用URI.decode() 解码