how to use web service on list view easily

June 20, 2017

how to use web service on list view easily

CONTET_MAIN.XML

LIST_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:orientation="vertical">

<TextView

android:id="@+id/name"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:paddingBottom="2dip"

android:paddingTop="6dip"

android:text="Name"

android:textSize="16sp"

android:textStyle="bold" />

<TextView

android:id="@+id/email"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:paddingBottom="2dip"

android:text="Email" />

<TextView

android:id="@+id/mobile"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:gravity="left"

android:text="Mobile: " />

</LinearLayout>

MAINACTIVITY.JAVA

package com.example.nc.myapplication123456;

import android.app.ListActivity;

import android.app.ProgressDialog;

import android.os.AsyncTask;

import android.os.Bundle;

import android.util.Log;

import android.widget.ListAdapter;

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 ListActivity {

// URL to get contacts JSON

private static String url = "https://raw.githubusercontent.com/mobilesiri/JSON-Parsing-in-Android/master/index.html";

// JSON Node names

private static final String TAG_STUDENTINFO = "studentsinfo";

private static final String TAG_ID = "id";

private static final String TAG_NAME = "name";

private static final String TAG_EMAIL = "email";

private static final String TAG_ADDRESS = "address";

private static final String TAG_GENDER = "gender";

private static final String TAG_PHONE = "phone";

private static final String TAG_PHONE_MOBILE = "mobile";

private static final String TAG_PHONE_HOME = "home";

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

// Calling async task to get json

new GetStudents().execute();

}

/**

* Async task class to get json by making HTTP call

private class GetStudents extends AsyncTask<Void, Void, Void> {

// Hashmap for ListView

ArrayList<HashMap<String, String>> studentList;

ProgressDialog pDialog;

@Override

protected void onPreExecute() {

super.onPreExecute();

// Showing progress dialog

pDialog = new ProgressDialog(MainActivity.this);

pDialog.setMessage("Please wait...");

pDialog.setCancelable(false);

pDialog.show();

}

@Override

protected Void doInBackground(Void... arg0) {

// Creating service handler class instance

WebRequest webreq = new WebRequest();

// Making a request to url and getting response

String jsonStr = webreq.makeWebServiceCall(url, WebRequest.GET);

Log.d("Response: ", "> " + jsonStr);

studentList = ParseJSON(jsonStr);

return null;

}

@Override

protected void onPostExecute(Void result) {

super.onPostExecute(result);

// Dismiss the progress dialog

if (pDialog.isShowing())

pDialog.dismiss();

/**

* Updating parsed JSON data into ListView

* */

ListAdapter adapter = new SimpleAdapter(

MainActivity.this, studentList,

R.layout.list_item, new String[]{TAG_NAME, TAG_EMAIL,

TAG_PHONE_MOBILE}, new int[]{R.id.name,

R.id.email, R.id.mobile});

setListAdapter(adapter);

}

private ArrayList<HashMap<String, String>> ParseJSON(String json) {

if (json != null) {

try {

// Hashmap for ListView

ArrayList<HashMap<String, String>> studentList = new ArrayList<HashMap<String, String>>();

JSONObject jsonObj = new JSONObject(json);

// Getting JSON Array node

JSONArray students = jsonObj.getJSONArray(TAG_STUDENTINFO);

// looping through All Students

for (int i = 0; i < students.length(); i++) {

JSONObject c = students.getJSONObject(i);

String id = c.getString(TAG_ID);

String name = c.getString(TAG_NAME);

String email = c.getString(TAG_EMAIL);

String address = c.getString(TAG_ADDRESS);

String gender = c.getString(TAG_GENDER);

// Phone node is JSON Object

JSONObject phone = c.getJSONObject(TAG_PHONE);

String mobile = phone.getString(TAG_PHONE_MOBILE);

String home = phone.getString(TAG_PHONE_HOME);

// tmp hashmap for single student

HashMap<String, String> student = new HashMap<String, String>();

// adding each child node to HashMap key => value

student.put(TAG_ID, id);

student.put(TAG_NAME, name);

student.put(TAG_EMAIL, email);

student.put(TAG_PHONE_MOBILE, mobile);

// adding student to students list

studentList.add(student);

}

return studentList;

} catch (JSONException e) {

e.printStackTrace();

return null;

}

} else {

Log.e("ServiceHandler", "Couldn't get any data from the url");

return null;

}

WEBREQUEST.JAVA

package com.example.nc.myapplication123456;

/**

* Created by nc on 4/26/2017.

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.io.OutputStreamWriter;

import java.net.HttpURLConnection;

import java.net.URL;

import java.net.URLEncoder;

import java.util.HashMap;

import java.util.Map;

import javax.net.ssl.HttpsURLConnection;

public class WebRequest {

static String response = null;

public final static int GET = 1;

public final static int POST = 2;

//Constructor with no parameter

public WebRequest() {

}

/**

* Making web service call

* @url - url to make request

* @requestmethod - http request method

public String makeWebServiceCall(String url, int requestmethod) {

return this.makeWebServiceCall(url, requestmethod, null);

}

/**

* Making service call

* @url - url to make request

* @requestmethod - http request method

* @params - http request params

public String makeWebServiceCall(String urladdress, int requestmethod,

HashMap<String, String> params) {

URL url;

String response = "";

try {

url = new URL(urladdress);

HttpURLConnection conn = (HttpURLConnection) url.openConnection();

conn.setReadTimeout(15000);

conn.setConnectTimeout(15000);

conn.setDoInput(true);

if (requestmethod == POST) {

conn.setRequestMethod("POST");

} else if (requestmethod == GET) {

conn.setRequestMethod("GET");

}

if (params != null) {

OutputStream os = conn.getOutputStream();

BufferedWriter writer = new BufferedWriter(

new OutputStreamWriter(os, "UTF-8"));

StringBuilder result = new StringBuilder();

boolean first = true;

for (Map.Entry<String, String> entry : params.entrySet()) {

if (first)

first = false;

else

result.append("&");

result.append(URLEncoder.encode(entry.getKey(), "UTF-8"));

result.append("=");

result.append(URLEncoder.encode(entry.getValue(), "UTF-8"));

}

writer.write(result.toString());

writer.flush();

writer.close();

os.close();

}

int responseCode = conn.getResponseCode();

if (responseCode == HttpsURLConnection.HTTP_OK) {

String line;

BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));

while ((line = br.readLine()) != null) {

response += line;

}

} else {

response = "";

}

} catch (Exception e) {

e.printStackTrace();

}

return response;

}

}

MANIFEST.XML

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="com.example.nc.myapplication123456">

<uses-permission android:name="android.permission.INTERNET"></uses-permission>

<application

android:allowBackup="true"

android:icon="@mipmap/ic_launcher"

android:label="@string/app_name"

android:supportsRtl="true"

android:theme="@style/AppTheme">

<activity

android:name=".MainActivity"

android:label="@string/app_name"

android:theme="@style/AppTheme.NoActionBar">

<intent-filter>

</intent-filter>

</activity>

</application>

</manifest>

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