如何使用HashMap將多個值放入ArrayList？

Question

我收到了JSON對象，並對其進行了解析。

數據如下。

[Parsed_showinfo_2 @ 0x9b4da80] n:88 pts:17425897 pts_time:726.079 pos:149422375 fmt:rgb24 sar:405/404 s:640x360 i:P iskey:1 type:I checksum:48E13810 plane_checksum:[48E13810]
[Parsed_showinfo_2 @ 0x9b4da80] n:89 pts:17471943 pts_time:727.998 pos:149646339 fmt:rgb24 sar:405/404 s:640x360 i:P iskey:0 type:P checksum:1AAD40E0 plane_checksum:[1AAD40E0]
[Parsed_showinfo_2 @ 0x9b4da80] n:90 pts:17503975 pts_time:729.332 pos:149806608 fmt:rgb24 sar:405/404 s:640x360 i:P iskey:1 type:I checksum:3DA5F0DB plane_checksum:[3DA5F0DB]

然后，我確實使用JSONParser（）解析了數據，因為我需要pts，pts_time值。

FileInputStream fstream = new FileInputStream("myfile");
DataInputStream in = new DataInputStream(fstream);
BufferedReader buff = new BufferedReader(new InputStreamReader(in));

//Which type put to ?
HashMap<String, ?> map = new HashMap<String, ?>();
//Should I use ArrayList too?
//ArrayList<HashMap<String, ?>> list = new ArrayList<HashMap<String, ?>>();

try {
    while (strLine = buff.readLine()) != null) {
        s = strLine.split(" ");
        pts = Long.parseLong(s[4].split(":")[1]);
        ptstime = s[5].split(":")[1];
    }
} catch (IOException ex) { }

我想在while循環中創建多個數組，然后返回結果值。

像這樣：

["pts": {1, 2, 3, 4, 5}, "ptstime": {10.11, 13.003, 15.12, 16.53, 18.10}]

pts和ptstime是鍵。

我如何在while循環中編碼

Answer 1

這是您可以執行的操作：

Map<String, List<Object>> map = new HashMap<>();
...
while (strLine = buff.readLine()) != null) {
    s = strLine.split(" ");
    pts = Long.parseLong(s[4].split(":")[1]);
    List<String> listPts = map.get("pts");
    if (listPts == null) {
        listPts = new ArrayList<>();
        map.put("pts", listPts);
    }
    listPts.add(pts);
    // Here apply the same logic to the rest
}

但是更好的方法可能是改為使用Map List ，如下所示：

List<Map<String, Object>> list = new ArrayList<>();
while (strLine = buff.readLine()) != null) {
    s = strLine.split(" ");
    Map<String, String> map = new HashMap<>();
    list.add(map);
    pts = Long.parseLong(s[4].split(":")[1]);
    map.put("pts", pts);
    // Here apply the same logic to the rest
}

Answer 2

將DataInputStream用作InputStreamReader參數時，它的用途是什么， FileInputStream應該已經可以了。

關於你的問題，我想你想要的是

Map<String, List<?>> map = new HashMap<>(2);
map.put("pts", new ArrayList<Long>());
map.put("ptstime", new ArrayList<Long>());

然后在while循環中

map.get("pts").add(pts.toString());
map.get("ptstime").add(ptstime);