Let us look at a Android Account and AccountManager examples.

What is Account?

It is a value type that represents an Account in the AccountManager.

What is an AccountManager

Users can access a centralized registry of online accounts using this class. A user enters credentials (username and password) once, enabling applications to access online resources with one click.

Accounts and authentication work differently on different online services, so the account manager uses pluggable authenticator modules. Account credentials are validated and information about accounts is stored by authenticators (written by third parties). It's like Google, Facebook, and Microsoft Exchange all have their own authenticator.

It's pretty common for servers to support authentication tokens, which are used to authenticate requests without sending the user's password. We can generate authentication tokens for applications with AccountManager, so the application doesn't need to handle passwords directly. AccountManager normally caches and reuses authentication tokens, but they need to be refreshed periodically.

You can read more Accountmanager (here.

Example 1: Account & AccountManager

This example will help you learn the following concepts:

How to initialize the AccountManager in Android
How to get an array of all accounts in an android device
How to get accounts and show them in a ListView in Android.

This example will comprise the following files:

ListItem.java
ListItemAdapter.java
MainActivity.java

Step 1: Create Project

Open your AndroidStudio IDE.
Go to File-->New-->Project to create a new project.

Step 2: Add Dependencies

No external dependencies are needed.

Step 3: Design Layouts

*(a). activity_main.xml

Create a file named activity_main.xml and design it as follows:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ListView android:id="@+id/listview1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

*(b). list_item.xml

Create a file named list_item.xml and design it as follows:

<?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/list_item_name"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

    <TextView android:id="@+id/list_item_type"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

Step 4: Write Code

Write Code as follows:

*(a). ListItem.java

Create a file named ListItem.java

Create a class to represent a List item

public class ListItem {

Add ListItem properties

    public String name;
    public String type;

Here is the full code

package com.bgstation0.android.sample.account_;

public class ListItem { 
    //end
    public String name;
    public String type;
    //end
}

*(b). ListItemAdapter.java

Create a file named ListItemAdapter.java

Create an adapter class by extending the ArrayAdapter

public class ListItemAdapter extends ArrayAdapter<ListItem> {

Initialize a LayoutInflater to null

    LayoutInflater mInflater = null;    // mInflaternullŏ.

Take a Context, Integer, and ListItem objects as parameters via the constructor

    public ListItemAdapter(Context context, int resource, ListItem[] objects){

Pass them to the constructor of the super class

        super(context, resource, objects);

Initialize the LayoutInflater using the context.getSystemService(). Pass in the LAYOUT_INFLATER_SERVICE

        mInflater = (LayoutInflater)context.getSystemService(context.LAYOUT_INFLATER_SERVICE);

Override the getView() function

    @Override
    public View getView(int position, View convertView, ViewGroup parent){

Check if the View object is null. Only then shall we inflate:

        if (convertView == null){
            convertView = mInflater.inflate(R.layout.list_item, null);  // nullȂ琶.
        }

Reference widgets and set their values:

        TextView tvName = (TextView)convertView.findViewById(R.id.list_item_name);  // tvName.
        tvName.setText(getItem(position).name); // name
        TextView tvType = (TextView)convertView.findViewById(R.id.list_item_type);  // tvType.
        tvType.setText(getItem(position).type); // type

Here is the full code

package com.bgstation0.android.sample.account_;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

public class ListItemAdapter extends ArrayAdapter<ListItem> {
//end
    LayoutInflater mInflater = null;    // mInflaternullŏ.
    //end
    public ListItemAdapter(Context context, int resource, ListItem[] objects){
        //end
        super(context, resource, objects);  
        //end
        mInflater = (LayoutInflater)context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
        //end
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent){
        //end
        if (convertView == null){
            convertView = mInflater.inflate(R.layout.list_item, null);  // nullȂ琶.
        }
        //end
        TextView tvName = (TextView)convertView.findViewById(R.id.list_item_name);  // tvName.
        tvName.setText(getItem(position).name); // name
        TextView tvType = (TextView)convertView.findViewById(R.id.list_item_type);  // tvType.
        tvType.setText(getItem(position).type); // type
        //end
        return convertView; // convertView.
    }

}

*(c). MainActivity.java

Create a file named MainActivity.java

Add our imports including the android.accounts.Account and android.accounts.AccountManager classes.

import java.util.ArrayList;
import android.accounts.Account;
import android.accounts.AccountManager;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListView;

Create our MainActivity. Extend the Activity class:

public class MainActivity extends Activity {

Override the onCreaet() function:

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

Initialize the AccountManagerby invoking the get() method and passing the Context:

        AccountManager accountManager = AccountManager.get(this);   // accountManager

Create an ArrayList of ListItem objects

        ArrayList<ListItem> list = new ArrayList<ListItem>();

Invoke the getAccounts() to get all the accounts in the device.

        Account[] accounts = accountManager.getAccounts();

Add all the accounts to our List.

        for (Account account : accounts){
            ListItem item = new ListItem();
            item.name = account.name;
            item.type = account.type;   
            list.add(item); 
        }

Reference a ListView

        ListView listView1 = (ListView)findViewById(R.id.listview1);

Set the adapter

        ListItem[] array = new ListItem[list.size()];   // array𐶐
        ListItemAdapter listItemAdapter = new ListItemAdapter(this, R.layout.list_item, list.toArray(array));   // arrayAdapter𐶐.
        listView1.setAdapter(listItemAdapter);  // listItemAdapter

Here is the full code

package com.bgstation0.android.sample.account_;
import java.util.ArrayList;
import android.accounts.Account;
import android.accounts.AccountManager;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListView;
//end
public class MainActivity extends Activity {
//end
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //end
        AccountManager accountManager = AccountManager.get(this);   // accountManager
        //end

        ArrayList<ListItem> list = new ArrayList<ListItem>();
        //end
        Account[] accounts = accountManager.getAccounts();
        //end
        for (Account account : accounts){
            ListItem item = new ListItem();
            item.name = account.name;
            item.type = account.type;   
            list.add(item); 
        }
        //end
        ListView listView1 = (ListView)findViewById(R.id.listview1);
        //end

        ListItem[] array = new ListItem[list.size()];   // array𐶐
        ListItemAdapter listItemAdapter = new ListItemAdapter(this, R.layout.list_item, list.toArray(array));   // arrayAdapter𐶐.
        listView1.setAdapter(listItemAdapter);  // listItemAdapter
        //end

    }

}

Run

Simply copy the source code into your Android Project,Build and Run.

Example 2: Initialize AccountManager

This tutorial will help you learn the following concepts:

How to get the AccountManager

This example will comprise the following files:

MainActivity.java

Step 1: Create Project

Open your AndroidStudio IDE.
Go to File-->New-->Project to create a new project.

Step 2: Dependencies

No dependencies are needed.

Step 3: Design Layouts

*(a). activity_main.xml

Create a file named activity_main.xml and design it as follows:

<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="${relativePackage}.${activityClass}" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</RelativeLayout>

Step 4: Write Code

Write Code as follows:

*(a). MainActivity.java

Create a file named MainActivity.java

Simply use the the get() method and pass in the context

        AccountManager accountManager = AccountManager.get(this);

Then you can cast it to string and show it:

        Toast.makeText(this, "accountManager = " + accountManager.toString(), Toast.LENGTH_LONG).show();    // accountManagero.

Here is the full code

package com.bgstation0.android.sample.accountmanager_;

import android.accounts.AccountManager;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        AccountManager accountManager = AccountManager.get(this);
        //end
        Toast.makeText(this, "accountManager = " + accountManager.toString(), Toast.LENGTH_LONG).show();    // accountManagero.
        //end
    }

}

Run

Simply copy the source code into your Android Project,Build and Run.

Example 3: Get AccountManager and Show it

This tutorial will help you learn the following concepts:

How to get the AccountManager and show it in a Toast message

This example will comprise the following files:

MainActivity.java

Step 1: Create Project

Open your AndroidStudio IDE.
Go to File-->New-->Project to create a new project.

Step 2: Add Dependencies

No dependencies are needed.

Step 3: Design Layouts

*(a). activity_main.xml

Create a file named activity_main.xml and design it as follows:

<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="${relativePackage}.${activityClass}" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</RelativeLayout>

Step 4: Write Code

Write Code as follows:

*(a). MainActivity.java

Create a file named MainActivity.java

Import AccountManager among other imports:

import android.accounts.AccountManager;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

Create a MainActivity

public class MainActivity extends Activity {

Override the onCreate:

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

Invoke the AccountManager.get(), passing in the context and cast it to string then show in a Toast message

        Toast.makeText(this, AccountManager.get(this).toString(), Toast.LENGTH_LONG).show();    // AccountManager.get(this)g[Xg\.

Here is the full code

package com.bgstation0.android.sample.accountmanager_;
import android.accounts.AccountManager;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;
//end
public class MainActivity extends Activity {
//end
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //end
        Toast.makeText(this, AccountManager.get(this).toString(), Toast.LENGTH_LONG).show();    // AccountManager.get(this)g[Xg\.
        //end
    }

}

Run

Simply copy the source code into your Android Project,Build and Run.

Example 4: List All Accounts

This example will comprise the following files:

ListItem.java
ListItemAdapter.java
MainActivity.java

Step 1: Create Project

Open your AndroidStudio IDE.
Go to File-->New-->Project to create a new project.

Step 2: Dependencies

No dependencies are needed.

Step 3: Design Layouts

*(a). activity_main.xml

Create a file named activity_main.xml and design it as follows:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ListView android:id="@+id/listview1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

*(b). list_item.xml

Create a file named list_item.xml and design it as follows:

<?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/list_item_name"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

Step 4: Write Code

Write Code as follows:

*(a). ListItem.java

Create a file named ListItem.java

Here is the full code

package com.bgstation0.android.sample.accountmanager_;

// XgACeNXListItem
public class ListItem { // ListItem̒`.
    public String name; // O.
}

*(b). ListItemAdapter.java

Create a file named ListItemAdapter.java

Here is the full code

package com.bgstation0.android.sample.accountmanager_;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

// ListItempA_v^[ListItemAdapter
public class ListItemAdapter extends ArrayAdapter<ListItem> {

    // otB[h̒`.
    LayoutInflater mInflater = null;    // mInflaternullŏ.

    // RXgN^
    public ListItemAdapter(Context context, int resource, ListItem[] objects){
        super(context, resource, objects);  // eRXgN^.
        mInflater = (LayoutInflater)context.getSystemService(context.LAYOUT_INFLATER_SERVICE);  // mInflater̎擾.
    }

    // ACe\̃JX^}CY.
    @Override
    public View getView(int position, View convertView, ViewGroup parent){
        // convertViewnull̎.
        if (convertView == null){
            convertView = mInflater.inflate(R.layout.list_item, null);  // nullȂ琶.
        }
        TextView tvName = (TextView)convertView.findViewById(R.id.list_item_name);  // tvName擾.
        tvName.setText(getItem(position).name); // nameZbg.
        return convertView; // convertViewԂ.
    }

}

*(c). MainActivity.java

Create a file named MainActivity.java

Here is the full code

package com.bgstation0.android.sample.accountmanager_;

import java.util.ArrayList;

import android.accounts.Account;
import android.accounts.AccountManager;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // AccountManagerIuWFNg擾, \.
        AccountManager accountManager = AccountManager.get(this);   // accountManagerɊi[.

        // AJEgXg̎擾.
        ArrayList<ListItem> list = new ArrayList<ListItem>();   // list𐶐.
        Account[] accounts = accountManager.getAccounts();  // accountManager.getAccountsaccounts擾.
        for (Account account : accounts){   // accountsaccountôvfJԂ.
            ListItem item = new ListItem(); // item𐶐.
            item.name = account.name;   // item.nameaccount.nameZbg.
            list.add(item); // list.additemǉ.
        }

        // listView1̎擾.
        ListView listView1 = (ListView)findViewById(R.id.listview1);    // listView1擾.

        // ListItemAdapter̐.
        ListItem[] array = new ListItem[list.size()];   // array𐶐.
        ListItemAdapter listItemAdapter = new ListItemAdapter(this, R.layout.list_item, list.toArray(array));   // arrayAdapter𐶐.
        listView1.setAdapter(listItemAdapter);  // listItemAdapterZbg.

    }

}

Run

Simply copy the source code into your Android Project,Build and Run.

Example 5: Get Accounts By Type

This tutorial will help you learn the following concepts:

How to get Accounts by Type in an Android Device

This example will comprise the following files:

ListItem.java
ListItemAdapter.java
MainActivity.java

Step 1: Create Project

Open your AndroidStudio IDE.
Go to File-->New-->Project to create a new project.

Step 2: Add Dependencies

Step 3: Design Layouts

*(a). activity_main.xml

Create a file named activity_main.xml and design it as follows:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ListView android:id="@+id/listview1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

*(b). list_item.xml

Create a file named list_item.xml and design it as follows:

<?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/list_item_name"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

    <TextView android:id="@+id/list_item_type"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

Step 4: Write Code

Write Code as follows:

*(a). ListItem.java

Create a file named ListItem.java

Create a simple model class

public class ListItem {
    public String name;
    public String type; 
}

Here is the full code

package com.bgstation0.android.sample.accountmanager_;

public class ListItem {
    public String name;
    public String type; 
}
//end

*(b). ListItemAdapter.java

Create a file named ListItemAdapter.java

Extend the ArrayAdapter

public class ListItemAdapter extends ArrayAdapter<ListItem> {

Create the constructor

```java
    public ListItemAdapter(Context context, int resource, ListItem[] objects){
        super(context, resource, objects);
        mInflater = (LayoutInflater)context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
    }

Override the getView() method. We inflate our list_item layout here:

    @Override
    public View getView(int position, View convertView, ViewGroup parent){
        // convertViewnull̎.
        if (convertView == null){
            convertView = mInflater.inflate(R.layout.list_item, null);
        }
        TextView tvName = (TextView)convertView.findViewById(R.id.list_item_name);  // tvName.
        tvName.setText(getItem(position).name); // name.
        TextView tvType = (TextView)convertView.findViewById(R.id.list_item_type);  // tvType.
        tvType.setText(getItem(position).type); // type.
        return convertView; // convertViewԂ.
    }

Here is the full code

package com.bgstation0.android.sample.accountmanager_;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

public class ListItemAdapter extends ArrayAdapter<ListItem> {
//end
    //Initialize the `LayoutInflater` to null
    LayoutInflater mInflater = null;
    //end
    public ListItemAdapter(Context context, int resource, ListItem[] objects){
        super(context, resource, objects);
        mInflater = (LayoutInflater)context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
    }
    //end

    @Override
    public View getView(int position, View convertView, ViewGroup parent){
        // convertViewnull̎.
        if (convertView == null){
            convertView = mInflater.inflate(R.layout.list_item, null);
        }
        TextView tvName = (TextView)convertView.findViewById(R.id.list_item_name);  // tvName.
        tvName.setText(getItem(position).name); // name.
        TextView tvType = (TextView)convertView.findViewById(R.id.list_item_type);  // tvType.
        tvType.setText(getItem(position).type); // type.
        return convertView; // convertViewԂ.
    }
        //end

}

*(c). MainActivity.java

Create a file named MainActivity.java

Add your imports

import java.util.ArrayList;
import android.accounts.Account;
import android.accounts.AccountManager;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

Extend the Activity class:

public class MainActivity extends Activity {

Get the AccountManager instance:

```java
        AccountManager accountManager = AccountManager.get(this);

Create an arraylist of ListItem objects

        ArrayList<ListItem> list = new ArrayList<ListItem>();

If you want to get Accounts use the getAccounts() method

        //Account[] accounts = accountManager.getAccounts();    // accountManager.getAccounts()

To get the accounts by type use the getAccountsByType() method as shown below:

        Account[] accounts = accountManager.getAccountsByType("com.google");

Now loop through the accounts and add them to our List

        for (Account account : accounts){
            ListItem item = new ListItem();
            item.name = account.name;
            item.type = account.type;
            list.add(item);
        }

Prepare a ListView

        ListView listView1 = (ListView)findViewById(R.id.listview1);

Bind the accounts to our adapter and then the adapter to the ListView:

        ListItem[] array = new ListItem[list.size()];   // array𐶐.
        ListItemAdapter listItemAdapter = new ListItemAdapter(this, R.layout.list_item, list.toArray(array));   // arrayAdapter𐶐.
        listView1.setAdapter(listItemAdapter);

Here is the full code

package com.bgstation0.android.sample.accountmanager_;

import java.util.ArrayList;
import android.accounts.Account;
import android.accounts.AccountManager;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
//end
public class MainActivity extends Activity {
//end
//Override the `onCreate()`:
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //end

        AccountManager accountManager = AccountManager.get(this);
        //end

        ArrayList<ListItem> list = new ArrayList<ListItem>();
        //end
        //Account[] accounts = accountManager.getAccounts();    // accountManager.getAccounts()
        //end
        Account[] accounts = accountManager.getAccountsByType("com.google");
        //end
        for (Account account : accounts){
            ListItem item = new ListItem();
            item.name = account.name;
            item.type = account.type;
            list.add(item);
        }
        //end

        ListView listView1 = (ListView)findViewById(R.id.listview1);
        //end

        ListItem[] array = new ListItem[list.size()];   // array𐶐.
        ListItemAdapter listItemAdapter = new ListItemAdapter(this, R.layout.list_item, list.toArray(array));   // arrayAdapter𐶐.
        listView1.setAdapter(listItemAdapter);  
        //end

    }

}

Run

Simply copy the source code into your Android Project,Build and Run.

[if exists]

More Concepts and Examples

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[loop type=post tags=chapter term=coil orderby=date order=asc]

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[else]

[/if]