ajax后台跨域处理

response.setContentType("text/html;charset=UTF-8");
response.setCharacterEncoding("UTF-8");
response.addHeader("Access-Control-Allow-Origin", "*");
PrintWriter writer = null;
try {
writer = response.getWriter();
String json = JsonUtils.writer().writeValueAsString(rs);//自己封装的bean转json格式的String
writer.print(json);
} catch (IOException e) {
e.printStackTrace();
}finally{
if(writer!=null){
writer.close();
}
}