Ajax returns 只有字符串化数组的第一个索引到 Spring 控制器

Question

这是完整的 JS 代码：

function getPoolsData(){
$.getJSON('../json/data.json', function(data) {

var date_from = new Date();
console.log(date_from);
var pools_hashrates = [{"date_from" : date_from}];

data.pools.forEach(function(pool){

var api_url = pool.api;
var poolName = pool.name;

if(pool.type == "forknote"){

    $.getJSON(api_url + 'stats', function(data) {

            var poolHashrate = data.pool.hashrate;

            pools_hashrates.push({"poolName" : poolName, "hashrate" : poolHashrate});

            console.log("Pool name: " + poolName + " Pool hashrate: " + parseInt(poolHashrate));
    });
}
else{
    $.getJSON(api_url + 'pool/stats', function(data) {

            var poolHashrate = data.pool_statistics.hashRate;

            console.log("Pool name: " + poolName + " Pool hashrate: " + parseInt(poolHashrate));

            pools_hashrates.push({"poolName" : poolName, "hashrate" : poolHashrate});

    });
}

});

console.log(pools_hashrates);

$.ajax({
  type: "POST",
  contentType : 'application/json; charset=utf-8',
  dataType : 'json',
  url: "/save",
  data: JSON.stringify(pools_hashrates),
  success :function(result) {
      console.log("Success!");
 }
});

});
}

控制器方法如下：

@RequestMapping("/save")
public @ResponseBody String getPoolsData(@RequestBody String string){

    System.out.println("Triggered: " + string);
    return "Success mvc";
}

控制器输出：

Triggered: [{"date_from":"2018-04-13T11:05:00.652Z"}]

问题是，只有数组的第一个索引被发送到控制器，而数组的长度约为 20。 console.log(pools_hashrates) 打印整个数组。通过按钮调用脚本。

Answer 1

Ajax 调用是异步的，这意味着它将同时触发所有 3 个，对 getPoolsData 的调用不会等待 get 完成，您需要设置 ajax 异步调用。

像这样

$.ajaxSetup({
    async: false
});

请注意，这会将所有 ajax 调用设置为异步，更好的做法是重写您的调用

$.ajax({
    url: "...",
    type: "GET",
    data: ...,
    async: false
});

只进行异步调用

或者您可以使用 setInterval 继续检查是否 jQuery.active == 0

jQuery.active == 0 // this tells you if you have active ajax calls

如果是这样的话

var myTimer = setInterval((function(){ 
    if (jQuery.active == 0){
        $.ajax({
            type: "POST",
            contentType : 'application/json; charset=utf-8',
            dataType : 'json',
            url: "/save",
            data: JSON.stringify(pools_hashrates),
            success :function(result) {
                console.log("Success!");
            }
        });
        clearInterval(myTimer); // stop the interval once you the get calls finished and you send the ajax call
    }
}, 1000)); // 1000 is the interval at which to check set in miliseconds

Ajax returns 只有字符串化数组的第一个索引到 Spring 控制器

Ajax returns only first index of stringified array to the Spring controller

javascript

ajax

json

spring-mvc

stringify