public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
UsersDAO dao = new UsersDAO();
List<Users> lt = dao.findAll();
//把数据库的数据变成json以后存储在服务器物理地址,让客户来访问
File file = new File("F://Tomcat//apache-tomcat-8.5.31//webapps//TestAndroid//Users.json");
file.createNewFile();
//用一个stringBuffer来存储着每次转换完成的string
StringBuffer sb = new StringBuffer();
sb.append("[");
int i= 0;
int size = lt.size();
for (Users user : lt) {
i++;
sb.append("{");
sb.append("\"id\":\""+user.getId()+"\",");
sb.append("\"name\":\""+user.getName()+"\",");
sb.append("\"age\":\""+user.getAge()+"\",");
sb.append("\"tupian\":\""+user.getTupian()+"\",");
sb.append("\"sex\":\""+user.getSex()+"\",");
sb.append("\"favorite\":\""+user.getFavorite()+"\",");
sb.append("\"pass\":\""+user.getPass()+"\"");
sb.append("}");
if (i<size) {
sb.append(",");
}
}
sb.append("]");
OutputStream os = new FileOutputStream(file);
os.write(sb.toString().getBytes());
out.print(sb.toString());
}
当然这肯定不是fastjson的全部底层,还需通过反射来了解传过来的是什么对象