利用jackson转成json字符串（ssh中）

public String getJsonString(Object o){
    ObjectMapper om = new ObjectMapper();
   StringWriter sw = new StringWriter();
   try{
      JsonGenerator jg = new JsonFactory().createJsonGenerator(ws);
      om.writeValue(jg,o);
      jg.close();
   }catch(){}
   return ws.toString() ;
}

public void writeJson(Object o) {
  String json = getJsonString(o);
  try{
      ServletActionContext.getResponse().getWriter().write(json);
   }catch(){}
}