To authenticate or save the information in an external database like oracle, MySQL, PostgreSQL, SQL server using other applications developed in java, .net, PHP, etc., languages, a restful web service application is created in android.
What is Web Service?
For exchanging information between two or more different types of applications, irrespective of their language or platform, a standard is set and that is known as Web Service. For example, we can use the Web Service for exchanging information between an android application and java or .net application.
Example:
File: activity_main.xml:
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity" > <EditText android:id="@+id/editText1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:layout_centerHorizontal="true" android:hint="Username" android:ems="10" /> <EditText android:id="@+id/editText2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/editText1" android:layout_below="@+id/editText1" android:layout_marginTop="67dp" android:ems="10" android:hint="Password" android:inputType="textPassword" /> <Button android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_marginBottom="24dp" android:layout_toRightOf="@+id/button1" android:text="Sign Up" /> <ProgressBar android:id="@+id/progressBar1" style="?android:attr/progressBarStyleLarge" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/button1" android:layout_below="@+id/editText2" android:layout_marginTop="22dp" /> <Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/editText2" android:layout_below="@+id/progressBar1" android:layout_marginLeft="22dp" android:text="Sign In" /> </RelativeLayout> |
File: activity_register_user.xml:
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" xmlns:tools="http://schemas.android.com/tools" tools:context=".RegisterUser"> <EditText android:id="@+id/editText1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:layout_centerHorizontal="true" android:layout_marginTop="15dp" android:ems="10" android:hint="Name" /> <EditText android:id="@+id/editText2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/editText1" android:layout_below="@+id/editText1" android:layout_marginTop="50dp" android:ems="10" android:hint="New Password" android:inputType="textPassword" /> <Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" android:text="Register" /> <ProgressBar android:id="@+id/progressBar1" style="?android:attr/progressBarStyleLarge" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/button1" android:layout_below="@+id/editText2" android:layout_marginTop="87dp" /> </RelativeLayout> |
File: build.gradle:
apply plugin: 'com.android.application' android { compileSdkVersion 28 defaultConfig { applicationId "com.example.radioapp" minSdkVersion 23 targetSdkVersion 28 versionCode 1 versionName "1.0" testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner" } buildTypes { release { minifyEnabled false proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro' } } sourceSets { main { assets { srcDirs 'src/main/assets', 'src/main/res/assets/' } } } } dependencies { implementation fileTree(dir: 'libs', include: ['*.jar']) implementation 'com.android.support:appcompat-v7:28.0.0' implementation 'com.android.support.constraint:constraint-layout:1.1.3' implementation 'com.android.support:design:28.0.0' implementation 'com.android.support:support-v4:28.0.0' testImplementation 'junit:junit:4.12' androidTestImplementation 'com.android.support.test:runner:1.0.2' androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2' android { useLibrary 'org.apache.http.legacy' } } |
Activity class:(File: MainActivity.java)
package com.example.radioapp; import android.annotation.SuppressLint; import android.app.Activity; import android.content.Intent; import android.os.AsyncTask; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.ProgressBar; import android.widget.Toast; import java.io.BufferedReader; import java.io.InputStream; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.List; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.NameValuePair; import org.apache.http.client.HttpClient; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpPost; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.message.BasicNameValuePair; public class MainActivity extends Activity { EditText password,userName; Button login,register; ProgressBar progressBar; protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); password=(EditText) findViewById(R.id.editText2); userName=(EditText) findViewById(R.id.editText1); login=(Button) findViewById(R.id.button1); register=(Button) findViewById(R.id.button2); //progess_msz.setVisibility(View.GONE); progressBar=(ProgressBar) findViewById(R.id.progressBar1); progressBar.setVisibility(View.GONE); register.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { // TODO Auto-generated method stub Intent intent=new Intent(MainActivity.this, RegisterUser.class); startActivity(intent); } }); login.setOnClickListener(new OnClickListener() { public void onClick(View v) { progressBar.setVisibility(View.VISIBLE); String s1=userName.getText().toString(); String s2=password.getText().toString(); new ExecuteTask().execute(s1,s2); } }); } class ExecuteTask extends AsyncTask<String, Integer, String> { @Override protected String doInBackground(String... params) { String res=PostData(params); return res; } @SuppressLint("WrongConstant") @Override protected void onPostExecute(String result) { progressBar.setVisibility(View.GONE); //progess_msz.setVisibility(View.GONE); Toast.makeText(getApplicationContext(), result, 3000).show(); } } public String PostData(String[] values) { String s=""; try { HttpClient httpClient=new DefaultHttpClient(); HttpPost httpPost=new HttpPost("http://10.0.0.8:7777/HttpPostServlet/servlet/Login"); List<NameValuePair> list=new ArrayList<NameValuePair>(); list.add(new BasicNameValuePair("name", values[0])); list.add(new BasicNameValuePair("pass",values[1])); httpPost.setEntity(new UrlEncodedFormEntity(list)); HttpResponse httpResponse= httpClient.execute(httpPost); HttpEntity httpEntity=httpResponse.getEntity(); s= readResponse(httpResponse); } catch(Exception exception) {} return s; } public String readResponse(HttpResponse res) { InputStream is=null; String return_text=""; try { is=res.getEntity().getContent(); BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(is)); String line=""; StringBuffer sb=new StringBuffer(); while ((line=bufferedReader.readLine())!=null) { sb.append(line); } return_text=sb.toString(); } catch (Exception e) { } return return_text; } } |
RegisterUser class:(File: RegisterUser.java)
package com.example.radioapp; import java.util.ArrayList; import java.util.List; import org.apache.http.NameValuePair; import org.apache.http.client.HttpClient; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpPost; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.message.BasicNameValuePair; import android.os.AsyncTask; import android.os.Bundle; import android.app.Activity; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.ProgressBar; public class RegisterUser extends Activity { EditText userName,password; Button register,login; ProgressBar progressBar; protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_register_user); userName=(EditText) findViewById(R.id.editText1);; password=(EditText) findViewById(R.id.editText2); register=(Button) findViewById(R.id.button1); progressBar=(ProgressBar) findViewById(R.id.progressBar1); progressBar.setVisibility(View.GONE); register.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { progressBar.setVisibility(View.VISIBLE); String s1=userName.getText().toString(); String s2=password.getText().toString(); new ExecuteTask().execute(s1,s2); } }); } class ExecuteTask extends AsyncTask<String, Integer, String> { @Override protected String doInBackground(String... params) { PostData(params); return null; } @Override protected void onPostExecute(String result) { progressBar.setVisibility(View.GONE); } } public void PostData(String[] values) { try { HttpClient httpClient=new DefaultHttpClient(); HttpPost httpPost=new HttpPost( "http://10.0.0.8:7777/HttpPostServlet/servlet/httpPostServlet"); List<NameValuePair> list=new ArrayList<NameValuePair>(); list.add(new BasicNameValuePair("name", values[0])); list.add(new BasicNameValuePair("pass",values[1])); httpPost.setEntity(new UrlEncodedFormEntity(list)); httpClient.execute(httpPost); } catch(Exception e) { System.out.println(e); } } } |
AndroidManifest:(File: AndroidManifest.xml)
In the AndroidManifest.xml file, we will add the code to provide the INTERNET permission.
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.radioapp"> <uses-permission android:name="android.permission.INTERNET" /> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name=".MainActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <activity android:name=".RegisterUser" android:label="@string/app_name" > </activity> </application> </manifest> |
Output 1:
Output 2:
