java - 如何在 JSON 中传递数组值？

Question

ArrayList<StylistArray>stylistsArr=new ArrayList<StylistArray>();
stylistsArr.add(new StylistArray("BqYWKWzs4r8SyGQvyqH2","18:30"));
stylistsArr.add(new StylistArray("at5kjx5FqIxbnMys8w4q","18:30"));
stylistsArr.add(new StylistArray("nFI5hxfIePx240dmqR0R","18:00"));
stylistsArr.add(new StylistArray("spxSj8UZem5uD0wL46EP","18:20"));

.

https://us-central.jshshskajshdala.net?dasa="+"2018-09-04"+"&ewsss="+"17:50"+"&stylist="+String.valueOf(stylistsArr) 

我想将这个 arrayList 与 url 一起传递。当我尝试传递数组值时，传递的是模型类的名称而不是类中的值

示例
我想传递这样的值:

[
  {
    "stylist": "BqYWKWzs4r8SyGQvyqH2",
    "endTime": "18:30"
  },
  {
    "stylist": "at5kjx5FqIxbnMys8w4q",
    "endTime": "18:30"
  },
  {
    "stylist": "nFI5hxfIePx240dmqR0R",
    "endTime": "18:00"
  },
  {
    "stylist": "spxSj8UZem5uD0wL46EP",
    "endTime": "18:00"
  }
]

Answer 1

就像@Mathan 和@Cris 所说的，您可以简单地使用 for 循环来创建您的 JSON 字符串。对于以下简单的 pojo:

public class StylistArray {
  // use a final so the value can't be change once the object is created.
  private final String stylist;
  private final String endTime;

  public StylistArray(String stylist, String endTime) {
    this.stylist = stylist;
    this.endTime = endTime;
  }

  public String getStylist() {
    return stylist;
  }

  public String getEndTime() {
    return endTime;
  }
}

您可以简单地执行以下操作:

List<StylistArray> list = new ArrayList<>();
// assume you have add all items to the list.

JSONArray jsonArray = new JSONArray();
try {
  // You need to use simple for loop instead the following foreach
  // because foreach is slower than traditional loop.
  for (StylistArray stylistArray : list) {
    // create JSON object for each item
    JSONObject jsonObject = new JSONObject();
    jsonObject.put("stylist", stylistArray.getStylist());
    jsonObject.put("endTime", stylistArray.getEndTime());

    // append it to your JSON array.
    jsonArray.put(jsonObject);
  }
} catch (JSONException e) {
  e.printStackTrace();
  // Error happens, try to handle it.
}

然后您可以从JSONArray 中获取字符串。我会让你找出答案；)