What is JSON Parser Android
JSON stands for the Javascript Object Notation. It is a programming language, minimal, textual, and a subset of JavaScript and an alternative to XML. We can parse the JSON object and array in Android.
Advantages of JSON over XML:
- Compared to XML, JSON is easier and faster for AJAX applications.
- Compared to XML, JSON is quicker and shorter to read and write.
- JSON uses an array.
- JSON is Human Readable.
- JSON is easy to parse.
Advantages of XML over JSON:
- XML supports Namespaces to allow for the sharing of standard structures.
- Compared to JSON, XML supports better representation for inheritance.
- XML is Human Readable.
- XML is easy to parse.
JSON object:
Similar to a map, the JSON object also contains key/value pairs, separated by a comma, where keys are strings and the values are the JSON types. The JSON object is represented by the { (curly brace).
Example:
{
"student": {
"name": "Rohan",
"id": 100,
"class": 6
}
} |
JSON array:
The JSON array is represented by the [ (square bracket).
Example 1:
["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"] |
Example 2:
{ "Student" :
[
{"id":"1","name":"Rohan","marks":"80"},
{"id":"2","name":"Rohit","marks":"90"}
]
} |
Parsing JSONArray in Android:
In the below example, we will parse the JSONArray containing the JSON Objects using the JSONArray class.
Example:
activity_main.xml
In the activity_main.xml file, we will drag a Textview from the palette.
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List_row.xml:
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Activity class:
In the MainActivity.java file, we will write the code to parse the XML using the JSON parser.
package com.example.radioapp;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String jsonStr = getListData();
try{
ArrayList> userList = new ArrayList<>();
ListView lv = (ListView) findViewById(R.id.user_list);
JSONObject jObj = new JSONObject(jsonStr);
JSONArray jsonArry = jObj.getJSONArray("users");
for(int i=0;i user = new HashMap<>();
JSONObject obj = jsonArry.getJSONObject(i);
user.put("name",obj.getString("name"));
user.put("designation",obj.getString("designation"));
user.put("location",obj.getString("location"));
userList.add(user);
}
ListAdapter adapter = new SimpleAdapter(MainActivity.this, userList, R.layout.list_row,new String[]{"name","designation","location"}, new int[]{R.id.name, R.id.designation, R.id.location});
lv.setAdapter(adapter);
}
catch (JSONException ex){
Log.e("JsonParser Example","unexpected JSON exception", ex);
}
}
private String getListData() {
String jsonStr = "{ \"users\" :[" +
"{\"name\":\"A\",\"designation\":\"Leader\",\"location\":\"City1\"}" +
",{\"name\":\"B\",\"designation\":\"Secretary\",\"location\":\"City2\"}" +
",{\"name\":\"C\",\"designation\":\"Accountant\",\"location\":\"City3\"}] }";
return jsonStr;
}
} |
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