json

问题 I'm making an Rails API call and return a single JSON object that has a nested User Object and a tag list array. However, I can't access the nested Object. this.props.post.user.name throws: Cannot read property 'name' of undefined. I am confused because when I make the call to PostsIndex in PostsIndex.js and get an array of objects and map through it I can access everything. Is there something I need to do when only dealing with a single object? PostShow.js import React, {Component} from

问题 I'm making an Rails API call and return a single JSON object that has a nested User Object and a tag list array. However, I can't access the nested Object. this.props.post.user.name throws: Cannot read property 'name' of undefined. I am confused because when I make the call to PostsIndex in PostsIndex.js and get an array of objects and map through it I can access everything. Is there something I need to do when only dealing with a single object? PostShow.js import React, {Component} from

问题 I'm trying to create and use a cache for a server JSON response. something like volley response caching does. https://stackoverflow.com/a/32022946/1993001 in Android I am using DIO for network operations. 回答1: You can you create your own cache with Interceptors on top of Dio requests. You can create in on your own: import 'package:dio/dio.dart'; class CacheInterceptor extends Interceptor { CacheInterceptor(); var _cache = new Map<Uri, Response>(); @override onRequest(RequestOptions options)

问题 Given these classes: @Value private static class Message { private final String type; private final MyType message; } @Value public class MyType { private final String foo; } Jackson will produce: { "Type" : "Test", "Message" : {"foo" : "bar"} } Is there some type of annotation or instruction I can give to Jackson to ask it to serialize the nested complex type as a string, e.g. the desired JSON would be: { "Type" : "Test", "Message" : "{\"foo\" : \"bar\"}" } I tried both of these annotations

问题 Given these classes: @Value private static class Message { private final String type; private final MyType message; } @Value public class MyType { private final String foo; } Jackson will produce: { "Type" : "Test", "Message" : {"foo" : "bar"} } Is there some type of annotation or instruction I can give to Jackson to ask it to serialize the nested complex type as a string, e.g. the desired JSON would be: { "Type" : "Test", "Message" : "{\"foo\" : \"bar\"}" } I tried both of these annotations

问题 Given these classes: @Value private static class Message { private final String type; private final MyType message; } @Value public class MyType { private final String foo; } Jackson will produce: { "Type" : "Test", "Message" : {"foo" : "bar"} } Is there some type of annotation or instruction I can give to Jackson to ask it to serialize the nested complex type as a string, e.g. the desired JSON would be: { "Type" : "Test", "Message" : "{\"foo\" : \"bar\"}" } I tried both of these annotations

问题 I've got a big database with analytics data written in JSON. I want to filter out rows with incorrect data: invalid json (some rows has something like that: '{"hello": "world' some attributes is not array so it would take '{"products": [1,2,3]}' and will leave out the '{"products": 1}' I want to do something like that: select * from analytics where (is_correct_json(json::json)) and (is_array(json::json->>'products')) How can I achieve that? 回答1: This is another good example why choosing the

问题 I've got a big database with analytics data written in JSON. I want to filter out rows with incorrect data: invalid json (some rows has something like that: '{"hello": "world' some attributes is not array so it would take '{"products": [1,2,3]}' and will leave out the '{"products": 1}' I want to do something like that: select * from analytics where (is_correct_json(json::json)) and (is_array(json::json->>'products')) How can I achieve that? 回答1: This is another good example why choosing the

问题 I've got a big database with analytics data written in JSON. I want to filter out rows with incorrect data: invalid json (some rows has something like that: '{"hello": "world' some attributes is not array so it would take '{"products": [1,2,3]}' and will leave out the '{"products": 1}' I want to do something like that: select * from analytics where (is_correct_json(json::json)) and (is_array(json::json->>'products')) How can I achieve that? 回答1: This is another good example why choosing the

问题 I've got a big database with analytics data written in JSON. I want to filter out rows with incorrect data: invalid json (some rows has something like that: '{"hello": "world' some attributes is not array so it would take '{"products": [1,2,3]}' and will leave out the '{"products": 1}' I want to do something like that: select * from analytics where (is_correct_json(json::json)) and (is_array(json::json->>'products')) How can I achieve that? 回答1: This is another good example why choosing the