java - 如何从数组列表中检索特定字段值并附加到列表视图

Question

我以对象数组的形式从后端获取响应，并将响应存储在数组列表中，我想从 ArrayList 中检索特定字段值并将其附加到列表视图。

这是我的代码：

Retrofit retrofit = builder.build();

        APIService apiservice = retrofit.create(APIService.class);
        Call<PostData> call = apiservice.transactiondetails(UID);
        call.enqueue(new Callback<PostData>() {
            @Override
            public void onResponse(@NonNull Call<PostData> call, @NonNull Response<PostData> response) {
                if (response.code() == 200) { // this  is the case for success
                    if (response.isSuccessful()) {
                        response.body();
//                        ArrayList dp = new HashMap<String, Array>();
//                        dp = Objects.requireNonNull(response.body()).getToken1();
                      ArrayList  dp  = Objects.requireNonNull(response.body()).getToken1();
                        Log.d(TAG, String.valueOf(dp));
                        System.out.println("hash map is" + dp);
                        Intent i = new Intent(deyaPay.this, TransactionDetails.class);
                        i.putExtra("Transactiondetails",dp);
                        startActivity(i);
                        Toast.makeText(deyaPay.this, "success" + dp, Toast.LENGTH_SHORT).show();
                        //Toast.makeText(getApplicationContext(), dp, Toast.LENGTH_LONG).show();
                    }
                }

and this is class for getting the response from backend:

public class PostData {

    @SerializedName("Token")
    @Expose
    private String token;

    public String getToken() {
        return token;
    }

    public void setToken(String token) {
        this.token = token;
    }

    @SerializedName("Details")
    @Expose
    private Map<String,Array> token1;

    public Map<String, Array> getToken1() {
        return token1;
    }

    public void setToken1(Map<String,Array> token1) {
        this.token1 = token1;
    }


}

那么如何将响应附加到 listview，这是我来自后端的响应：

[
        {
        Amount = 4;
        TransactionID = deyaPay;
        method = "Money Sent using deyaPay";
        timestamp = "2018-09-03T06:01:41.306Z";
    },
        {
        Amount = 2;
        Token = "tok_1D69olLMFuWYhKXrAqwmTprz";
        TransactionID = "ch_1D69omLMFuWYhKXrYpbNEtGH";
        method = "Requested by";
        timestamp = "2018-09-03T04:37:40.147Z";
    },
        {
        Amount = 5000;
        TransactionID = deyaPay;
        method = "Money Sent using deyaPay";
        timestamp = "2018-09-03T04:01:00.565Z";
    },
        {
        Amount = 50;
        TransactionID = deyaPay;
        method = "Money Sent using deyaPay";
        timestamp = "2018-09-03T03:59:01.708Z";
    },
        {
        Amount = 2;
        TransactionID = deyaPay;
        method = "Money Sent using deyaPay";
        timestamp = "2018-09-03T03:58:26.964Z";
    },
        {
        Amount = 1;
        Token = "tok_1D68nBLMFuWYhKXrGM2AN2IF";
        method = "Add Money to deyaPay account using credit card/debit card";
        timestamp = "2018-09-03T03:31:58.008Z";
    },
        {
        Amount = 5;
        Token = "tok_1D68cpLMFuWYhKXrM7oc2X7j";
        method = "Add Money to deyaPay account using credit card/debit card";
        timestamp = "2018-09-03T03:21:16.281Z";
    },
        {
        Amount = 2;
        Token = "tok_1D5pE1LMFuWYhKXr9BMvQ1dm";
        method = "Add Money to deyaPay account using credit card/debit card";
        timestamp = "2018-09-02T06:38:22.188Z";
    },
        {
        Amount = 2;
        Token = "tok_1D5pCxLMFuWYhKXrJoRcbN8o";
        method = "Add Money to deyaPay account using credit card/debit card";
        timestamp = "2018-09-02T06:37:16.393Z";
    }]

标签： javaandroidjsonhashmap

Answer 1

你的 json 应该是这样的：

[{
        "Amount": "4",
        "Token": "tok_1D69olLMFuWYhKXrAqwmTprz",
        "TransactionID": "deyaPay",
        "method": "Money Sent using deyaPay",
        "timestamp": "2018-09-03T06:01:41.306Z"
    },
    {
        "Amount": "4",
        "Token": "tok_1D69olLMFuWYhKXrAqwmTprz",
        "TransactionID": "deyaPay",
        "method": "Money Sent using deyaPay",
        "timestamp": "2018-09-03T06:01:41.306Z"
    },
    {
        "Amount": "4",
        "Token": "tok_1D69olLMFuWYhKXrAqwmTprz",
        "TransactionID": "deyaPay",
        "method": "Money Sent using deyaPay",
        "timestamp": "2018-09-03T06:01:41.306Z"
    },
    {
        "Amount": "4",
        "Token": "tok_1D69olLMFuWYhKXrAqwmTprz",
        "TransactionID": "deyaPay",
        "method": "Money Sent using deyaPay",
        "timestamp": "2018-09-03T06:01:41.306Z"
    },
    {
        "Amount": "4",
        "Token": "tok_1D69olLMFuWYhKXrAqwmTprz",
        "TransactionID": "deyaPay",
        "method": "Money Sent using deyaPay",
        "timestamp": "2018-09-03T06:01:41.306Z"
    },
    {
        "Amount": "4",
        "Token": "tok_1D69olLMFuWYhKXrAqwmTprz",
        "TransactionID": "deyaPay",
        "method": "Money Sent using deyaPay",
        "timestamp": "2018-09-03T06:01:41.306Z"
    },
    {
        "Amount": "4",
        "Token": "tok_1D69olLMFuWYhKXrAqwmTprz",
        "TransactionID": "deyaPay",
        "method": "Money Sent using deyaPay",
        "timestamp": "2018-09-03T06:01:41.306Z"
    },
    {
        "Amount": "4",
        "Token": "tok_1D69olLMFuWYhKXrAqwmTprz",
        "TransactionID": "deyaPay",
        "method": "Money Sent using deyaPay",
        "timestamp": "2018-09-03T06:01:41.306Z"
    },
    {
        "Amount": "4",
        "Token": "tok_1D69olLMFuWYhKXrAqwmTprz",
        "TransactionID": "deyaPay",
        "method": "Money Sent using deyaPay",
        "timestamp": "2018-09-03T06:01:41.306Z"
    }
]

你的响应应该是一个对象数组。那就是你得到的错误，当响应是一个数组时，你试图解析一个对象。

在您的 listview 适配器中，您使用 arraylist 中的值将文本设置为项目：

amount.setText(data.get(position).getAmount());
       token.setText(data.get(position).getToken());

我在这里给你一个例子，说明如何使用你需要的自定义适配器实现列表视图：https ://medium.com/mindorks/custom-array-adapters-made-easy-b6c4930560dd