我有一个从JSON网址获取数据的应用。它与一个URL完美配合,但我需要同时从两个JSON URL获取数据。像一些URL中的一些数据和另一个URL中的一些数据。并在两个textViews中显示它们。
这是我的应用,它目前不加载任何数据。
MainActivity:
public class MainActivity extends Activity {
//URL to get JSON Array
private static String url1 = "http://api.worldbank.org/countries/de?format=json";
private static String url2 = "http://api.worldbank.org/countries/it?format=json";
//JSON Node Names
private static final String CountryNAME1 = "name";
private static final String CountryNAME2 = "name";
JSONArray user = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new GetJSONTask().execute(url1);
//new GETJSONTask().execute(url2);
}
class GetJSONTask extends AsyncTask<String, Void, JSONObject> {
protected JSONObject doInBackground(String... urls) {
// Creating new JSON Parser
JSONParser jParser = new JSONParser();
// Getting JSON from URL
JSONObject json1 = jParser.getJSONFromUrl(url1);
JSONObject json2 = jParser.getJSONFromUrl(url2);
return json1;
}
protected void onPostExecute(JSONObject json1, JSONObject json2) {
//Getting JSON Array
try {
//For Country 1
// Get the array
JSONArray countryArC1 = json1.getJSONArray("myValues");
JSONObject countryObC1 = countryArC1.getJSONObject(0);
JSONArray countryAr2C1 = countryArC1.getJSONArray(1);
JSONObject countryOb2C1 = countryAr2C1.getJSONObject(0);
//For Country 2
// Get the array
JSONArray countryArC2 = json2.getJSONArray("myValues");
JSONObject countryObC2 = countryArC2.getJSONObject(0);
JSONArray countryAr2C2 = countryArC2.getJSONArray(1);
JSONObject countryOb2C2 = countryAr2C2.getJSONObject(0);
//Storing JSON item in a Variable
String name1 = countryOb2C1.getString(CountryNAME1);
String name2 = countryOb2C2.getString(CountryNAME2);
//Importing TextView
final TextView textView1 = (TextView)findViewById(R.id.url1);
final TextView textView2 = (TextView)findViewById(R.id.url2);
//Set JSON Data in TextView
textView1.setText(name1);
textView2.setText(name2);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
JSONParser:
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
//System.out.println("url getJSONfromUrl " + url);
//url = "http://api.worldbank.org/countries/CA/indicators/SP.POP.TOTL?date=1980:1981&format=json";
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
System.out.println("JSONParser string: " + json);
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
if (json.startsWith("[")) {
// We have a JSONArray
try {
jObj = new JSONObject();
jObj.put("data", new JSONArray(json));
} catch (JSONException e) {
Log.d("JSON Parser", "Error parsing JSONArray " + e.toString());
}
return jObj;
}
// try parse the string to a JSON object
/*try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}*/
// return JSON String
return jObj;
}
}
XML:
<TextView
android:id="@+id/url1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/url2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/url1"
android:layout_marginTop="104dp"
/>
我认为主要问题是new GetJSONTask().execute(url1);
和JSONObject json1 = jParser.getJSONFromUrl(url1);
因为我不能拥有2个GetJSONTASK并且无法同时返回json1和json2。
有什么想法吗?
答案 0 :(得分:5)
我建议您将方法更改为
class GetJSONTask extends AsyncTask<String, Void, JSONObject[]> {
...
protected JSONObject[] doInBackground(String... urls) {
// Creating new JSON Parser
JSONParser jParser = new JSONParser();
// Getting JSON from URL
JSONObject[] jsons = new JSONObject[2];
jsons[0] = jParser.getJSONFromUrl(url1);
jsons[1] = jParser.getJSONFromUrl(url2);
return jsons;
}
protected void onPostExecute(JSONObject[] jsons) {
JSONObject json1 = jsons[0];
JSONObject json2 = jsons[1];
// do you work after this
}
}
希望这有帮助!
答案 1 :(得分:0)
变体A)您可以像这样执行GetJSONTask
:
new GetJSONTask().execute(url1, url2);
并访问AsyncTask中的URL,如下所示:
class GetJSONTask extends AsyncTask<String, Void, JSONObject[]> {
...
JSONObject[] doInBackground(String... urls) {
// Getting JSON from URL
JSONObject json1 = jParser.getJSONFromUrl(urls[1]);
JSONObject json2 = jParser.getJSONFromUrl(url2[2]);
return new JSONObject[] {json1, json2};
}
void onPostExecute(JSONObject[] jsons) { ... }
}
变体B)如果要使进程真正并行运行,可以添加另一个AsyncTask,它创建2个子任务并等待其结果。在大多数设备上,这将是执行该任务所需时间的一半。
class GetTwoJsonsTask extends AsyncTask<String, Void, JSONObject[]> {
JSONObject[] doInBackground(urls) {
task1 = new GetJSONTask().execute(urls[1]);
task2 = new GetJSONTask().execute(urls[2]);
// block until sub-tasks are finished
JSONObject json1 = task1.get();
JSONObject json2 = task2.get();
return new JSONObject[] {json1, json2};
}
void onPostExecute(JSONObject[] jsons) { ... }
}
答案 2 :(得分:0)
这就是我的方法,很容易做到
public class GetSetting extends AsyncTask<List<String>,Void,List<String>> {
String urls[] = new String[]{"http:// first url",
"http:// second url"};
@Override
protected ArrayList<String> doInBackground(List<String>... lists) {
HttpURLConnection urlConnection;
InputStream inputStream;
BufferedReader bufferedReader;
URL urlIfSup;
ArrayList<String> result = new ArrayList<>();
try {
// here to connect and get a different type of data
for (int i = 0; i < 2; i++){ // this one for connect the url from url array in every loop
urlIfSup = new URL(urls[i]);
urlConnection = (HttpURLConnection) urlIfSup.openConnection();
inputStream = urlConnection.getInputStream();
bufferedReader = new BufferedReader(new InputStreamReader(inputStream,"utf-8"));
String data = bufferedReader.readLine();
while(bufferedReader.readLine() != null){
data += bufferedReader.readLine();
}
if (i==0) {
// do something for the first url
}else if (i==1){
// do something for the second url
// use jSON if you want
// then do this at the last url
urlConnection.disconnect();
inputStream.close();
bufferedReader.close();
}
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return result;
}
}