Ajax僅將字符串化數組的第一個索引返回給Spring控制器

Question

這是整個JS代碼：

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!");
 }
});

});
}

這是控制器方法：

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

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

並輸出一個控制器：

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

問題在於，只有數組的第一個索引發送到控制器，而數組的長度約為20。 console.log(pools_hashrates)打印整個數組。 通過按鈕調用腳本。

Answer 1

Ajax調用是異步的，這意味着它將同時觸發所有三個調用，對getPoolsData的調用不會等待獲取完成，您需要將ajax調用設置為異步。

像這樣

$.ajaxSetup({
    async: false
});

請注意，這會將所有ajax調用設置為異步，更好的方法是這樣重寫您的調用

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

只發出異步呼叫

或者您可以使用setInterval繼續檢查jQuery.active == 0

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

如果會是這樣的話

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