后端统一返回Jackson封装对象

public class Message {
    // 200 成功 404 失败
//    private int code;
    private Integer state;
    private String message;
    // 服务器要返回给浏览器的数据
    private Map<String, Object> data = new HashMap<String, Object>();    //可选

    public static Message success() {
        Message message = new Message();
        message.setState(200);
        message.setMessage("处理成功");
        return message;
    }
    /*默认返回*/
    public static Message fail() {
        Message message = new Message();
        message.setState(404);
        message.setMessage("处理失败");
        return message;
    }

    public static Message fail(String meg) {
        Message message = new Message();
        message.setState(404);
        message.setMessage(meg);
        return message;
    }

    public Message add(String key, Object value) {
        this.data.put(key, value);
        return this;
    }

    public Message() {
        super();
        // TODO Auto-generated constructor stub
    }

　　//get*() and set*(..)

@GetMapping("/*")
public Message *(..){
    ......
    return Message.fail();
}