Question

我遇到下一个错误：

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException:
class org.json.simple.JSONArray cannot be cast to class
org.json.simple.JSONObject (org.json.simple.JSONArray and
org.json.simple.JSONObject are in unnamed module of loader 'app')

获取JSON的端点是：

https://www.okex.com/api/spot/v3/instruments

我已经搜索了错误，我认为问题是我正在获取JSONArray而不是JSONObject，但是我需要按键过滤，因为我需要从json中获取每个“ base_currency”。

下面是给我错误的原始代码：

private String UrlBase = "https://www.okex.com/";
private URL url;
private String inline="";
private JSONObject jobj;
private JSONObject jobj1;
private Scanner sc;
private String Symbols = "api/spot/v3/instruments";
private String Param1= "base_currency";
private JSONArray arr;
private JSONArray arr1;
private JSONParser prs;
private HttpURLConnection conn;
private ArrayList Monedas = new ArrayList();
private Conexion conc = new Conexion();

public void CargarMonedasNuevasOkex() throws IOException {



    try {
        url = new URL(UrlBase+Symbols);
    } catch (MalformedURLException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    } 

    try {
        conn = (HttpURLConnection)url.openConnection();
    } catch (Exception e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }

    conn.setRequestMethod("GET");
    conn.connect(); 

    int responsecode = conn.getResponseCode(); 

    if(responsecode != 200) {

        throw new RuntimeException("HttpResponseCode: " +responsecode);

    }
    else{

        sc = new Scanner(url.openStream());

        while(sc.hasNext())
        {
            inline+= sc.nextLine();
        }
        sc.close();

        JSONParser parse = new JSONParser();
        try {

            jobj1 = (JSONObject) parse.parse(inline);

        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        arr1 = (JSONArray) jobj1.get(Param1);
        System.out.println(arr.get(0));
        for( int a=0; a<arr1.size(); a++ ) {

            jobj1 = (JSONObject) arr1.get(a);
        }
       }
    }

Answer 1

代替

#font is an arabic font, and font_path is pointing to that location.
        font = ImageFont.truetype(
            font=font_path, size=size,
            layout_engine=ImageFont.LAYOUT_RAQM)

        h, w = font.getsize(text, direction='rtl')
        offset = font.getoffset(text)
        H, W = int(1.5 * h), int(1.5 * w)
        imgSize = H, W
        img = Image.new(mode='1', size=imgSize, color=0)
        draw = ImageDraw.Draw(img)
        pos = ((H-h)/2, (W-w)/2)
        draw.text(pos, text, fill=255, font=font,
                  direction='rtl', align='center')

做

arr1 = (JSONArray) jobj1.get(Param1);

哦和

arr1=job1 ;//or jsut use the same variable

应该是

jobj1 = (JSONObject) parse.parse(inline);

然后

 jobj1 = (JSONArray) parse.parse(inline);

基本上在链接中，前提是您得到的是jsonArray而不是包含数组的对象

Answer 2

为您的要求根据键获取值，您可以尝试下面的代码，该代码根据JSON格式进行了修改。

set

我如何通过JSONArray筛选键

2 个答案: