时间戳

首页 > 解决方案 > 如何在不崩溃的情况下提取 JSON 信息？

java - 如何在不崩溃的情况下提取 JSON 信息？

问题描述

我正在使用普通循环从文件中提取 json 信息并将它们放入普通数组适配器中，一切都已完全设置，但是当我运行应用程序时总是崩溃，我修改了所有代码并且没有错误。这是代码：

如果需要，我可以包含其他代码。

private QueryUtils() {
}

/**
 * Return a list of {@link Earthquake} objects that has been built up from
 * parsing a JSON response.
 */
public static ArrayList<Earthquake> extractEarthquakes() {

    // Create an empty ArrayList that we can start adding earthquakes to
    ArrayList<Earthquake> earthquakes = new ArrayList<>();

    // Try to parse the SAMPLE_JSON_RESPONSE. If there's a problem with the way the JSON
    // is formatted, a JSONException exception object will be thrown.
    // Catch the exception so the app doesn't crash, and print the error message to the logs.
    try {

        // Create a JSONObject from the SAMPLE_JSON_RESPONSE string
        JSONObject baseJsonResponse = new JSONObject(SAMPLE_JSON_RESPONSE);

        // Extract the JSONArray associated with the key called "features",
        // which represents a list of features (or earthquakes).
        JSONArray earthquakeArray = baseJsonResponse.getJSONArray("features");

        // For each earthquake in the earthquakeArray, create an {@link Earthquake} object
        for (int i = 0; i < earthquakeArray.length(); i++) {

            // Get a single earthquake at position i within the list of earthquakes
            JSONObject currentEarthquake = earthquakeArray.getJSONObject(i);

            // For a given earthquake, extract the JSONObject associated with the
            // key called "properties", which represents a list of all properties
            // for that earthquake.
            JSONObject properties = currentEarthquake.getJSONObject("properties");

            // Extract the value for the key called "mag"


            // Extract the value for the key called "place"
            String location = properties.getString("place");
            String magnitude = properties.getString("mag");
            // Extract the value for the key called "time"
            String time = properties.getString("time");

            // Extract the value for the key called "url"


            // Create a new {@link Earthquake} object with the magnitude, location, time,
            // and url from the JSON response.
            Earthquake earthquake = new Earthquake(magnitude, location, time);

            // Add the new {@link Earthquake} to the list of earthquakes.
            earthquakes.add(earthquake);
        }

    } catch (JSONException e) {
        // If an error is thrown when executing any of the above statements in the "try" block,
        // catch the exception here, so the app doesn't crash. Print a log message
        // with the message from the exception.
        Log.e("QueryUtils", "Problem parsing the earthquake JSON results", e);
    }

    // Return the list of earthquakes
    return earthquakes;
}

}

这是错误消息：

E/AndroidRuntime: FATAL EXCEPTION: main
          Process: com.example.android.quakereport, PID: 8512
          android.content.res.Resources$NotFoundException: Resource ID 
#0x0

logcat 图像 错误图像

显然错误不是json解析错误它是从getview方法中找不到的资源所以我以图像的形式添加了这个代码，因为我无法识别它们： 代码的第一部分代码 的第二部分

标签： javaandroidview

解决方案

删除return super.getView(position,convertView,parent);你做错了，getView()如果convertView为null，你不需要返回/调用，你只需要膨胀它。我建议您查找有关 custom 的教程ArrayAdapter。

推荐阅读