Ajax校验是否重复的实现代码

@responsebody 
@requestmapping("entityfindbycode") 
public string entityfindbycode(entity bean, httpsession httpsession, model m,httpservletresponse res) throws ioexception{ 
  res.setcontenttype("text/plain; charset=utf-8"); 
  //res.reset(); 
  //printwriter out = res.getwriter(); 
  string data=null; 
  @suppresswarnings("unchecked") 
  list<entity> list = (list<entity>) this.service.find("beanbycode", "entity", new object[]{bean.getcode()}); 
  if(list.size()==0){ 
    data="yes"; 
  }else{ 
    data="no"; 
  } 
  res.getoutputstream().write(data.getbytes()); 
  //out.print(data); 
  //out.flush(); 
  //out.close(); 
  return data; 
}

$.ajax({ 
      url    :'entityfindbycode', 
      type   :'post', 
      datatype :'text', 
      data   :{code:$("#code").val()},//{key,value} 
      success  :function(data) { 
        if (data == "yes"){ 
          document.getelementbyid("msg-code").innerhtml = "(<fmt:message key='warn.field.required.unique' bundle='${bundle }' />)"; 
          return true; 
        } 
        else { 
          $("#div-code").addclass("has-error"); 
          document.getelementsbyname("code")[0].value = "";  
          //document.getelementsbyname("code")[0].setattribute("placeholder", "<fmt:message key='warn.duplicate' bundle='${bundle }' />");  
          document.getelementbyid("msg-code").innerhtml = "(<fmt:message key='warn.duplicate' bundle='${bundle }' /> !!!)"; 
          return false; 
        } 
      } 
    });