标准化后端向前端传来的Json数据

后端响应固定格式给前端：

1，创建一个专门存储数据的类；分别存储响应状态码code，响应数据，传输的消息。

public class CommonData {int code;Object data;String message;public CommonData(int code, String message) {this.code = code;this.message = message;}public CommonData(int code, Object data, String message) {this.code = code;this.data = data;this.message = message;}public int getCode() {return code;}public void setCode(int code) {this.code = code;}public Object getData() {return data;}public void setData(Object data) {this.data = data;}public String getMessage() {return message;}public void setMessage(String message) {this.message = message;}
}

2，后端向前端传输

@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {String account=req.getParameter("account");String password=req.getParameter("password");System.out.println(account);System.out.println(password);PrintWriter printWriter=resp.getWriter();User user= null;CommonData commonData=null;try {user = dao.logindao(account,password);if(user==null) {commonData=new CommonData(201,"账号或密码输入有误，请重新输入！");}else {commonData=new CommonData(200,user,"登录成功");}} catch (SQLException throwables) {throwables.printStackTrace();commonData=new CommonData(500,"服务器忙...请稍后重试！");}ObjectMapper objectMapper=new ObjectMapper();String json=objectMapper.writeValueAsString(commonData);printWriter.print(json);}

3，前端接收后端传来的Json数据

login() {this.$http.post("LoginServlet", jsonToString(this.from)).then(resp => {if (resp.data.code == 201) {this.$message({message: resp.data.message,type: 'warning'});} else if (resp.data.code == 200) {this.$message({message: resp.data.message,type: 'success'});sessionStorage.setItem("account", resp.data.data.account);this.$router.push("/main"); //在js中进行路由导航}})}