我正在尝试创建一个新闻阅读器应用程序，其中使用JSON从api检索新闻内容并存储在ListView中，以便用户可以看到文章的不同标题。 我创建了2个AsyncTask：
第一个用于从JSONArray中检索热门故事的文章ID列表。我使用for循环检索每个单独的文章Id，该循环运行10次以获得10个文章ID。
第二个AsyncTask在第一个内部调用。我需要使用文章的特定ID在第二个AsyncTask中传递另一个url，以便获得我想要插入＆＃34; articleId＆＃34;的文章ID，标题和链接。 ＆＃34;标题＆＃34;和＆＃34; url＆＃34;我的桌子栏目。
我在显示表格内容时遇到问题。 我的目标是，只有在AsynTask填充了所有10行之后，才会显示我的表的内容。
这就是我的代码现在的样子：
public class MainActivity extends AppCompatActivity {
DownloadIdList idTask;
DownloadArticle articleTask;
SQLiteDatabase newsReaderDB;
ListView listView;
ArrayList<String> articlesList = new ArrayList<String>();
ArrayAdapter<String> arrayAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
idTask = new DownloadIdList();
listView = (ListView) findViewById(R.id.listView);
arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, articlesList);
listView.setAdapter(arrayAdapter);
try {
newsReaderDB = this.openOrCreateDatabase("News", MODE_PRIVATE, null);
newsReaderDB.execSQL("CREATE TABLE IF NOT EXISTS topStories (id INTEGER PRIMARY KEY, articleId INT(10), title VARCHAR, url VARCHAR)");
//newsReaderDB.execSQL("DROP TABLE topStories");
//Toast.makeText(getApplicationContext(),"Database deleted", Toast.LENGTH_LONG).show();
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "Can't create or open Database On Create", Toast.LENGTH_LONG).show();
}
try {
idTask.execute("https://hacker-news.firebaseio.com/v0/topstories.json?print=pretty");
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(),"Can't download URL", Toast.LENGTH_LONG).show();
}
}
public class DownloadIdList extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
String result = "";
URL url;
HttpURLConnection urlConnection = null;
try {
url = new URL(urls[0]);
urlConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = urlConnection.getInputStream();
InputStreamReader reader = new InputStreamReader(inputStream);
int data = reader.read();
while (data != -1) {
char current = (char) data;
result += current;
data = reader.read();
}
return result;
}catch (Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(),"Can't get Top Stories Id's" ,Toast.LENGTH_LONG).show();
}
return null;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
try {
JSONArray idArray = new JSONArray(result);
for (int i=0; i < 10; i++) {
int value = idArray.getInt(i);
Log.i("Top Stories Id", String.valueOf(value));
String id = String.valueOf(value);
articleTask = new DownloadArticle();
try {
articleTask.execute("https://hacker-news.firebaseio.com/v0/item/" + id + ".json?print=pretty");
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(),"can't get article info from id",Toast.LENGTH_LONG).show();
}
}
}catch (JSONException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(),"Can't get JSON Object",Toast.LENGTH_LONG).show();
}
}
}
public class DownloadArticle extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
String content = "";
URL url;
HttpURLConnection urlConnection = null;
try {
url = new URL(urls[0]);
urlConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = urlConnection.getInputStream();
InputStreamReader reader = new InputStreamReader(inputStream);
int data = reader.read();
while (data != -1) {
char current = (char) data;
content += current;
data = reader.read();
}
return content;
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Can't get Articles after retrieving the id", Toast.LENGTH_LONG).show();
}
return null;
}
@Override
protected void onPostExecute(String content) {
super.onPostExecute(content);
try {
JSONObject jsonObject = new JSONObject(content);
int idInfo = jsonObject.getInt("id");
String title = String.valueOf(jsonObject.getString("title"));
title = title.replaceAll("'","''");
String urlien = String.valueOf(jsonObject.getString("url"));
//newsReaderDB = openOrCreateDatabase("News", MODE_PRIVATE, null);
newsReaderDB.execSQL("INSERT INTO topStories (articleId, title, url) VALUES(" + idInfo + ", '" + title + "','" + urlien + "');");
showData();
}catch (JSONException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Can't get Article", Toast.LENGTH_LONG).show();
}
}
}
/*public void showDatabase() {
try {
newsReaderDB = this.openOrCreateDatabase("News", MODE_PRIVATE, null);
Cursor c = newsReaderDB.rawQuery("SELECT * FROM topStories", null);
c.moveToFirst();
int idIndex = c.getColumnIndex("id");
int a_idIndex = c.getColumnIndex("articleId");
int titleIndex = c.getColumnIndex("title");
int urlIndex = c.getColumnIndex("url");
c.moveToFirst();
while (c != null ) {
Log.i("Id", String.valueOf(c.getInt(idIndex)));
Log.i("Article id", String.valueOf(c.getInt(a_idIndex)));
Log.i("Title", c.getString(titleIndex));
Log.i("Url Link", c.getString(urlIndex));
c.moveToNext();
}
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Unable to List Database", Toast.LENGTH_LONG).show();
}
}*/
public void showData() {
try {
Cursor cursor = newsReaderDB.rawQuery("SELECT * FROM topStories", null);
if (cursor.moveToFirst()) {
do {
String id = String.valueOf(cursor.getInt(cursor.getColumnIndex("id")));
String a_id = String.valueOf(cursor.getInt(cursor.getColumnIndex("articleId")));
String title = cursor.getString(cursor.getColumnIndex("title"));
String url = cursor.getString(cursor.getColumnIndex("url"));
Log.i("id", id);
Log.i("article id", a_id);
Log.i("title", title);
Log.i("url", url);
} while (cursor.moveToNext());
} cursor.close();
}catch (Exception e) {
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.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
输出结果为：
10-15 12:23:42.755 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12713089
10-15 12:23:42.756 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12713249
10-15 12:23:42.756 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12711343
10-15 12:23:42.756 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12711511
10-15 12:23:42.757 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12713056
10-15 12:23:42.757 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12709220
10-15 12:23:42.757 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12707606
10-15 12:23:42.757 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12712577
10-15 12:23:42.757 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12709820
10-15 12:23:42.757 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12712454
10-15 12:23:43.013 32635-32635/com.iboundiaye.newsreader I/id: 1
10-15 12:23:43.013 32635-32635/com.iboundiaye.newsreader I/article id: 12713089
10-15 12:23:43.013 32635-32635/com.iboundiaye.newsreader I/title: KiCad: A commitment to freedom
10-15 12:23:43.013 32635-32635/com.iboundiaye.newsreader I/url: https://giving.web.cern.ch/content/kicad-development-1
10-15 12:23:43.259 32635-32635/com.iboundiaye.newsreader I/id: 1
10-15 12:23:43.259 32635-32635/com.iboundiaye.newsreader I/article id: 12713089
10-15 12:23:43.259 32635-32635/com.iboundiaye.newsreader I/title: KiCad: A commitment to freedom
10-15 12:23:43.259 32635-32635/com.iboundiaye.newsreader I/url: https://giving.web.cern.ch/content/kicad-development-1
10-15 12:23:43.259 32635-32635/com.iboundiaye.newsreader I/id: 2
10-15 12:23:43.259 32635-32635/com.iboundiaye.newsreader I/article id: 12713249
10-15 12:23:43.259 32635-32635/com.iboundiaye.newsreader I/title: What has happened down here is the winds have changed
10-15 12:23:43.259 32635-32635/com.iboundiaye.newsreader I/url: http://andrewgelman.com/2016/09/21/what-has-happened-down-here-is-the-winds-have-changed/
10-15 12:23:43.467 32635-32635/com.iboundiaye.newsreader I/id: 1
10-15 12:23:43.467 32635-32635/com.iboundiaye.newsreader I/article id: 12713089
10-15 12:23:43.467 32635-32635/com.iboundiaye.newsreader I/title: KiCad: A commitment to freedom
10-15 12:23:43.467 32635-32635/com.iboundiaye.newsreader I/url: https://giving.web.cern.ch/content/kicad-development-1
10-15 12:23:43.467 32635-32635/com.iboundiaye.newsreader I/id: 2
10-15 12:23:43.467 32635-32635/com.iboundiaye.newsreader I/article id: 12713249
10-15 12:23:43.467 32635-32635/com.iboundiaye.newsreader I/title: What has happened down here is the winds have changed
10-15 12:23:43.467 32635-32635/com.iboundiaye.newsreader I/url: http://andrewgelman.com/2016/09/21/what-has-happened-down-here-is-the-winds-have-changed/
10-15 12:23:43.467 32635-32635/com.iboundiaye.newsreader I/id: 3
10-15 12:23:43.467 32635-32635/com.iboundiaye.newsreader I/article id: 12711343
10-15 12:23:43.467 32635-32635/com.iboundiaye.newsreader I/title: A single byte write opened a root execution exploit
10-15 12:23:43.467 32635-32635/com.iboundiaye.newsreader I/url: https://daniel.haxx.se/blog/2016/10/14/a-single-byte-write-opened-a-root-execution-exploit/
10-15 12:23:43.722 32635-32635/com.iboundiaye.newsreader I/id: 1
10-15 12:23:43.722 32635-32635/com.iboundiaye.newsreader I/article id: 12713089
10-15 12:23:43.722 32635-32635/com.iboundiaye.newsreader I/title: KiCad: A commitment to freedom
10-15 12:23:43.722 32635-32635/com.iboundiaye.newsreader I/url: https://giving.web.cern.ch/content/kicad-development-1
10-15 12:23:43.722 32635-32635/com.iboundiaye.newsreader I/id: 2
10-15 12:23:43.722 32635-32635/com.iboundiaye.newsreader I/article id: 12713249
10-15 12:23:43.722 32635-32635/com.iboundiaye.newsreader I/title: What has happened down here is the winds have changed
10-15 12:23:43.722 32635-32635/com.iboundiaye.newsreader I/url: http://andrewgelman.com/2016/09/21/what-has-happened-down-here-is-the-winds-have-changed/
10-15 12:23:43.722 32635-32635/com.iboundiaye.newsreader I/id: 3
10-15 12:23:43.722 32635-32635/com.iboundiaye.newsreader I/article id: 12711343
10-15 12:23:43.722 32635-32635/com.iboundiaye.newsreader I/title: A single byte write opened a root execution exploit
10-15 12:23:43.723 32635-32635/com.iboundiaye.newsreader I/url: https://daniel.haxx.se/blog/2016/10/14/a-single-byte-write-opened-a-root-execution-exploit/
10-15 12:23:43.723 32635-32635/com.iboundiaye.newsreader I/id: 4
10-15 12:23:43.723 32635-32635/com.iboundiaye.newsreader I/article id: 12711511
10-15 12:23:43.723 32635-32635/com.iboundiaye.newsreader I/title: Books Programmers Don't Really Read (2008)
10-15 12:23:43.723 32635-32635/com.iboundiaye.newsreader I/url: http://www.billthelizard.com/2008/12/books-programmers-dont-really-read.html
10-15 12:23:43.909 32635-32635/com.iboundiaye.newsreader W/System.err: org.json.JSONException: No value for url
10-15 12:23:43.910 32635-32635/com.iboundiaye.newsreader W/System.err: at org.json.JSONObject.get(JSONObject.java:389)
10-15 12:23:43.910 32635-32635/com.iboundiaye.newsreader W/System.err: at org.json.JSONObject.getString(JSONObject.java:550)
10-15 12:23:43.910 32635-32635/com.iboundiaye.newsreader W/System.err: at com.iboundiaye.newsreader.MainActivity$DownloadArticle.onPostExecute(MainActivity.java:216)
10-15 12:23:43.910 32635-32635/com.iboundiaye.newsreader W/System.err: at com.iboundiaye.newsreader.MainActivity$DownloadArticle.onPostExecute(MainActivity.java:161)
10-15 12:23:43.910 32635-32635/com.iboundiaye.newsreader W/System.err: at android.os.AsyncTask.finish(AsyncTask.java:632)
10-15 12:23:43.910 32635-32635/com.iboundiaye.newsreader W/System.err: at android.os.AsyncTask.access$600(AsyncTask.java:177)
10-15 12:23:43.910 32635-32635/com.iboundiaye.newsreader W/System.err: at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
10-15 12:23:43.910 32635-32635/com.iboundiaye.newsreader W/System.err: at android.os.Handler.dispatchMessage(Handler.java:102)
10-15 12:23:43.910 32635-32635/com.iboundiaye.newsreader W/System.err: at android.os.Looper.loop(Looper.java:135)
10-15 12:23:43.910 32635-32635/com.iboundiaye.newsreader W/System.err: at android.app.ActivityThread.main(ActivityThread.java:5221)
10-15 12:23:43.910 32635-32635/com.iboundiaye.newsreader W/System.err: at java.lang.reflect.Method.invoke(Native Method)
10-15 12:23:43.910 32635-32635/com.iboundiaye.newsreader W/System.err: at java.lang.reflect.Method.invoke(Method.java:372)
10-15 12:23:43.914 32635-32635/com.iboundiaye.newsreader W/System.err: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
10-15 12:23:43.914 32635-32635/com.iboundiaye.newsreader W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
然后继续提供一组递增的数据，直到第9条。 在这一点上它应该给予第10条，但由于某种原因，它发现它为空，因此它跳过一组并显示直到第9条。
我想要的输出是：
10-15 12:23:42.755 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12713089
10-15 12:23:42.756 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12713249
10-15 12:23:42.756 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12711343
10-15 12:23:42.756 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12711511
10-15 12:23:42.757 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12713056
10-15 12:23:42.757 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12709220
10-15 12:23:42.757 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12707606
10-15 12:23:42.757 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12712577
10-15 12:23:42.757 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12709820
10-15 12:23:42.757 32635-32635/com.iboundiaye.newsreader I/Top Stories Id: 12712454
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/id: 1
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/article id: 12713089
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/title: KiCad: A commitment to freedom
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/url: https://giving.web.cern.ch/content/kicad-development-1
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/id: 2
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/article id: 12713249
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/title: What has happened down here is the winds have changed
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/url: http://andrewgelman.com/2016/09/21/what-has-happened-down-here-is-the-winds-have-changed/
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/id: 3
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/article id: 12711343
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/title: A single byte write opened a root execution exploit
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/url: https://daniel.haxx.se/blog/2016/10/14/a-single-byte-write-opened-a-root-execution-exploit/
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/id: 4
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/article id: 12711511
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/title: Books Programmers Don't Really Read (2008)
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/url: http://www.billthelizard.com/2008/12/books-programmers-dont-really-read.html
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/id: 5
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/article id: 12709220
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/title: Intel will add deep-learning instructions to its processors
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/url: http://lemire.me/blog/2016/10/14/intel-will-add-deep-learning-instructions-to-its-processors/
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/id: 6
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/article id: 12707606
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/title: Be Kind
10-15 12:23:45.109 32635-32635/com.iboundiaye.newsreader I/url: https://www.briangilham.com/blog/2016/10/10/be-kind
10-15 12:23:45.110 32635-32635/com.iboundiaye.newsreader I/id: 7
10-15 12:23:45.110 32635-32635/com.iboundiaye.newsreader I/article id: 12712577
10-15 12:23:45.110 32635-32635/com.iboundiaye.newsreader I/title: The Ops Identity Crisis
10-15 12:23:45.110 32635-32635/com.iboundiaye.newsreader I/url: http://www.susanjfowler.com/blog/2016/10/13/the-ops-identity-crisis
10-15 12:23:45.110 32635-32635/com.iboundiaye.newsreader I/id: 8
10-15 12:23:45.110 32635-32635/com.iboundiaye.newsreader I/article id: 12709820
10-15 12:23:45.110 32635-32635/com.iboundiaye.newsreader I/title: Easy Amazon EC2 Instance Comparison
10-15 12:23:45.110 32635-32635/com.iboundiaye.newsreader I/url: http://www.ec2instances.info/
10-15 12:23:45.110 32635-32635/com.iboundiaye.newsreader I/id: 9
10-15 12:23:45.110 32635-32635/com.iboundiaye.newsreader I/article id: 12712454
10-15 12:23:45.110 32635-32635/com.iboundiaye.newsreader I/title: 5900 online stores found skimming
10-15 12:23:45.110 32635-32635/com.iboundiaye.newsreader I/url: https://gwillem.github.io/2016/10/11/5900-online-stores-found-skimming/
（最后包括第10条）
答案 0 :(得分：0)
试试这个： 公共类MainActivity扩展了AppCompatActivity {
DownloadIdList idTask;
DownloadArticle articleTask;
SQLiteDatabase newsReaderDB;
ListView listView;
ArrayList<String> articlesList = new ArrayList<String>();
ArrayList<String> idList = new ArrayList<String>();
ArrayAdapter<String> arrayAdapter;
int i=0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
idTask = new DownloadIdList();
listView = (ListView) findViewById(R.id.listView);
arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, articlesList);
listView.setAdapter(arrayAdapter);
try {
newsReaderDB = this.openOrCreateDatabase("News", MODE_PRIVATE, null);
newsReaderDB.execSQL("CREATE TABLE IF NOT EXISTS topStories (id INTEGER PRIMARY KEY, articleId INT(10), title VARCHAR, url VARCHAR)");
//newsReaderDB.execSQL("DROP TABLE topStories");
//Toast.makeText(getApplicationContext(),"Database deleted", Toast.LENGTH_LONG).show();
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "Can't create or open Database On Create", Toast.LENGTH_LONG).show();
}
try {
idTask.execute("https://hacker-news.firebaseio.com/v0/topstories.json?print=pretty");
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(),"Can't download URL", Toast.LENGTH_LONG).show();
}
}
public class DownloadIdList extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
String result = "";
URL url;
HttpURLConnection urlConnection = null;
try {
url = new URL(urls[0]);
urlConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = urlConnection.getInputStream();
InputStreamReader reader = new InputStreamReader(inputStream);
int data = reader.read();
while (data != -1) {
char current = (char) data;
result += current;
data = reader.read();
}
return result;
}catch (Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(),"Can't get Top Stories Id's" ,Toast.LENGTH_LONG).show();
}
return null;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
try {
JSONArray idArray = new JSONArray(result);
for (int i=0; i < 10; i++) {
int value = idArray.getInt(i);
Log.i("Top Stories Id", String.valueOf(value));
String id = String.valueOf(value);
idList.add(id);
/* articleTask = new DownloadArticle();
try {
articleTask.execute("https://hacker-news.firebaseio.com/v0/item/" + id + ".json?print=pretty");
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(),"can't get article info from id",Toast.LENGTH_LONG).show();
}*/
}
for(int l=0;l<idList.size();l++){
articleTask = new DownloadArticle();
i = l;
try {
articleTask.execute("https://hacker-news.firebaseio.com/v0/item/" + id + ".json?print=pretty");
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(),"can't get article info from id",Toast.LENGTH_LONG).show();
}
}
}catch (JSONException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(),"Can't get JSON Object",Toast.LENGTH_LONG).show();
}
}
}
public class DownloadArticle extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
String content = "";
URL url;
HttpURLConnection urlConnection = null;
try {
url = new URL(urls[0]);
urlConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = urlConnection.getInputStream();
InputStreamReader reader = new InputStreamReader(inputStream);
int data = reader.read();
while (data != -1) {
char current = (char) data;
content += current;
data = reader.read();
}
return content;
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Can't get Articles after retrieving the id", Toast.LENGTH_LONG).show();
}
return null;
}
@Override
protected void onPostExecute(String content) {
super.onPostExecute(content);
try {
JSONObject jsonObject = new JSONObject(content);
int idInfo = jsonObject.getInt("id");
String title = String.valueOf(jsonObject.getString("title"));
title = title.replaceAll("'","''");
String urlien = String.valueOf(jsonObject.getString("url"));
//newsReaderDB = openOrCreateDatabase("News", MODE_PRIVATE, null);
newsReaderDB.execSQL("INSERT INTO topStories (articleId, title, url) VALUES(" + idInfo + ", '" + title + "','" + urlien + "');");
if(i==(idList.size()-1){//last row is inserted in db
showData();
}
}catch (JSONException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Can't get Article", Toast.LENGTH_LONG).show();
}
}
}
/*public void showDatabase() {
try {
newsReaderDB = this.openOrCreateDatabase("News", MODE_PRIVATE, null);
Cursor c = newsReaderDB.rawQuery("SELECT * FROM topStories", null);
c.moveToFirst();
int idIndex = c.getColumnIndex("id");
int a_idIndex = c.getColumnIndex("articleId");
int titleIndex = c.getColumnIndex("title");
int urlIndex = c.getColumnIndex("url");
c.moveToFirst();
while (c != null ) {
Log.i("Id", String.valueOf(c.getInt(idIndex)));
Log.i("Article id", String.valueOf(c.getInt(a_idIndex)));
Log.i("Title", c.getString(titleIndex));
Log.i("Url Link", c.getString(urlIndex));
c.moveToNext();
}
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Unable to List Database", Toast.LENGTH_LONG).show();
}
}*/
public void showData() {
try {
Cursor cursor = newsReaderDB.rawQuery("SELECT * FROM topStories", null);
if (cursor.moveToFirst()) {
do {
String id = String.valueOf(cursor.getInt(cursor.getColumnIndex("id")));
String a_id = String.valueOf(cursor.getInt(cursor.getColumnIndex("articleId")));
String title = cursor.getString(cursor.getColumnIndex("title"));
String url = cursor.getString(cursor.getColumnIndex("url"));
Log.i("id", id);
Log.i("article id", a_id);
Log.i("title", title);
Log.i("url", url);
} while (cursor.moveToNext());
} cursor.close();
}catch (Exception e) {
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.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}