Android JSON Parsing Example
JSON Parsing in Android
(Without using Asynctask)
JSON is an easy way to parse and access data stored in
JSON format. In this tutorial you can see how to parse JSON in android. Before
going to program, let’s see JSON format type. JSON format is two types:
1. Object
Type
2. Array
Type.
An Example:
Object Type JSON:
{
'name' : 'Tara',
'phone' :
123456789
};
Array Type JSON:
[
{
‘name' : 'Tara',
'phone' :
123456789
},
{
‘name' : 'Tara',
'phone' : 123456789
},
.
.
.
];
In this tutorial, I am taking an example of following
JSON which will give you list of News and each “NewsLines” have different
Head-Lines and Date-Lines. You can get this JSON by accessing http://mfeeds.timesofindia.indiatimes.com/Feeds/jsonfeed?newsid=3947071&format=simplejson
If you observe carefully, you can see { and ]. The main
difference between these two is object and array. Curly bracket { represents JSONObject and Square bracket [ represents
JSONArray.
Now we will create Parser class. This parser class is
used to execute the JSON link and get the JSON data and returns JSON Object.
public class Parser {
static InputStream is = null;
static
JSONObject jObj = null;
static String json = "";
public
JSONObject getJSONData(String url){
try{
DefaultHttpClient
client = new DefaultHttpClient();
HttpPost
post = new HttpPost(url);
HttpResponse
response = client.execute(post);
HttpEntity
entity = response.getEntity();
is =
entity.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();
} catch
(Exception e) {
Log.e("Buffer
Error", "Error converting result " +
e.toString());
}
try {
jObj = new
JSONObject(json);
} catch
(JSONException e) {
Log.e("JSON
Parser", "Error parsing data " + e.toString());
}
return jObj;
}
}
After creating Parser class, You need to know how you can
use it in your MainActivity class. In NewsLines, there are multiple strings i.e
HeadLine and DateLine. So you need to define these in your class.
private static final String NEWS = "NewsML";
private static final String NEWS_LINE = "NewsLines";
private static final String HEAD_LINE = "HeadLine";
private static final String DATE_LINE = "DateLine";
Now it’s main thing How I can get the data. Here I will
use Parser class and provide the specific url. Depending upon JSON object, you
will get the length of json array and write the code like this.
Parser parser = new
Parser();
JSONObject json = parser.getJSONData(url);
news =
json.getJSONArray(NEWS);
for(int
i=0;i<news.length();i++){
JSONObject
object = news.getJSONObject(i);
JSONObject
newsline = object.getJSONObject(NEWS_LINE);
String
headLine = newsline.getString(HEAD_LINE);
String dateLine =
newsline.getString(DATE_LINE);
}
After getting all the data showing in list view. So
MainActivity class is like this:
public class
MainActivity extends ListActivity {
private static String url = "http://mfeeds.timesofindia.indiatimes.com/Feeds/jsonfeed?newsid=3947071&amp;format=simplejson";
private static final String NEWS = "NewsML";
private static final String NEWS_LINE = "NewsLines";
private static final String HEAD_LINE = "HeadLine";
private static final String DATE_LINE = "DateLine";
JSONArray news = null;
@Override
protected void
onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ArrayList<HashMap<String, String>> newsList =
new ArrayList<HashMap<String, String>>();
Parser parser = new
Parser();
JSONObject json = parser.getJSONData(url);
try{
news =
json.getJSONArray(NEWS);
for(int
i=0;i<news.length();i++){
JSONObject
object = news.getJSONObject(i);
JSONObject
newsline = object.getJSONObject(NEWS_LINE);
String headLine =
newsline.getString(HEAD_LINE);
String dateLine =
newsline.getString(DATE_LINE);
HashMap<String, String> map = new
HashMap<String, String>();
map.put(HEAD_LINE,
headLine);
map.put(DATE_LINE,
dateLine);
newsList.add(map);
}
}catch(JSONException
e){
e.printStackTrace();
}
ListAdapter adapter = new
SimpleAdapter(this, newsList,
R.layout.listview_item,
new String[] { HEAD_LINE, DATE_LINE },
new int[] {R.id.tv_headLine, R.id.tv_dateLine });
setListAdapter(adapter);
}
}
activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:android1="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ListView
android1:id="@android:id/list"
android1:layout_width="match_parent"
android1:layout_height="wrap_content" >
</ListView>
</LinearLayout>
listview_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#DEC397"
android:orientation="vertical" >
<TextView
android:id="@+id/tv_headLine"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="HeadLine"
android:textColor="#DE5084"
android:textSize="18sp"
android:textAppearance="?android:attr/textAppearanceLarge" />
<TextView
android:id="@+id/tv_dateLine"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#5BC990"
android:textSize="14sp"
android:text="DateTime"
android:textAppearance="?android:attr/textAppearanceMedium" />
</LinearLayout>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#DEC397"
android:orientation="vertical" >
<TextView
android:id="@+id/tv_headLine"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="HeadLine"
android:textColor="#DE5084"
android:textSize="18sp"
android:textAppearance="?android:attr/textAppearanceLarge" />
<TextView
android:id="@+id/tv_dateLine"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#5BC990"
android:textSize="14sp"
android:text="DateTime"
android:textAppearance="?android:attr/textAppearanceMedium" />
</LinearLayout>
In your manifest file, don’t forget to mansion internet
connection permission.
<uses-permission
android:name="android.permission.INTERNET" />
You Will Get Out Put Like This:
Here We are directly getting data on Main UI Thread, So there is a possibility to getting NetworkOnMainThread exception.
You can get exception like this, when you directly accessing data on Main UI thread:
So it's better parsing data using asynctask.
In Next tutorial I explained how JSON parsing happening using Threading mechanism.
