[2020 version] How to send an email using Android Studio Javamail

I wrote a program to send an email directly from the app in Android Studio with reference to How to send an email from Android Zero using Javamail. Could not build due to a series of errors. Most of the articles were written before 2017 (whether my method was wrong or obsolete), and none of them worked, so I searched for the latest introduction method.

Conclusion: The way to download a jar file and import it into a library is old!

The method often described in the article I searched and found was to download three jar files from javamail-android and manually copy them to the libs folder of Android Studio and install them. However, I found that it can be introduced just by writing it in build.gradle without doing such troublesome things, so I will write how to do it.

: one: Described in AndroidManifest.xml (Internet access permission)

Add permissions. Internet access eliminates the need for users to manually turn on permissions. Add the following sentence: <uses-permission android: name =" android.permission.INTERNET "/>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.mailsend">

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

: two: Described in dependencies of build.gradle (app level)

This is the point. Please add the following two sentences.

build.gradle

dependencies {
···abridgement···

    implementation 'com.sun.mail:android-mail:1.6.5'
    implementation 'com.sun.mail:android-activation:1.6.5'
}

: three: Describe the layout

This time I will write a program that sends an email when the button is tapped.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Email sending test"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Send" />

</LinearLayout>

: four: Program description

Please change the email address, password, title, and body of your Google account as appropriate. In addition, this program is designed to email you.

To change the destination address, please refer to "msg.setRecipients (javax.mail.Message.RecipientType.TO, javax.mail.internet.InternetAddress.parse (account +"@gmail.com "));Please change account + "@ gmail.com" to the destination address. (Example of sending from the entered Google account to [email protected]:msg.setRecipients (javax.mail.Message.RecipientType.TO, javax.mail.internet.InternetAddress.parse ("[email protected]")) ; `)

You can also change the email type to CC or BCC, or send to multiple addresses by changing the "javax.mail.Message.RecipientType.TO" part. (Click here for details: http://javadrive.s25.xrea.com/javamail/smtp/index3.html)

MainActivity.java

package com.example.mailsend;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

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

        Button button=findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                asyncTask a=new asyncTask();
                a.execute("Gmail account name (@gmail.Before com)",
                        "Gmail password","Test title","send completely\n Write the text here") ;
            }
        });
    }

    private class asyncTask extends android.os.AsyncTask{
        protected String account;
        protected String password;
        protected String title;
        protected String text;

        @Override
        protected Object doInBackground(Object... obj){
            account=(String)obj[0];
            password=(String)obj[1];
            title=(String)obj[2];
            text=(String)obj[3];

            java.util.Properties properties = new java.util.Properties();
            properties.put("mail.smtp.host", "smtp.gmail.com");
            properties.put("mail.smtp.auth", "true");
            properties.put("mail.smtp.port", "465");
            properties.put("mail.smtp.socketFactory.post", "465");
            properties.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");

            final javax.mail.Message msg = new javax.mail.internet.MimeMessage(javax.mail.Session.getDefaultInstance(properties, new javax.mail.Authenticator(){
                @Override
                protected javax.mail.PasswordAuthentication getPasswordAuthentication() {
                    return new javax.mail.PasswordAuthentication(account,password);
                }
            }));

            try {
                msg.setFrom(new javax.mail.internet.InternetAddress(account + "@gmail.com"));
                //Send an email to yourself
                msg.setRecipients(javax.mail.Message.RecipientType.TO, javax.mail.internet.InternetAddress.parse(account + "@gmail.com"));
                msg.setSubject(title);
                msg.setText(text);

                javax.mail.Transport.send(msg);

            } catch (Exception e) {
                return (Object)e.toString();
            }

            return (Object)"Transmission is complete";

        }
        @Override
        protected void onPostExecute(Object obj) {
            //Display a message on the screen
            Toast.makeText(MainActivity.this,(String)obj,Toast.LENGTH_LONG).show();
        }
    }
}

: iphone: It looks like it was executed

Tap the "Send" button to send the email. When the transmission is complete, the toast will be displayed. Confirmation of reception

: chains: Reference site

https://it-engineer-info.com/language/android-app/2142/ http://7ujm.net/android/javamail.html https://stackoverflow.com/questions/32103337/android-studio-noclassdeffounderror