How to test email of junit

How can it test email of junit? Solution use dumbster as a fake smtp server 1. add dependency to pom.xml

    dumbster
    dumbster
    1.6
    test

2. add bean definition to spring applicationContext.xml

    <constructor-arg index="0" value="2525"/>

using javax mail session

    
        
            127.0.0.1
            2525
        
    


    <constructor-arg ref="mailSession" type="javax.mail.Session"/>

or if you using spring mail sender:

<bean class="org.springframework.mail.javamail.JavaMailSenderImpl" id="mailSender" p:host="localhost" p:port="2525"/>

3. define one util class

import com.dumbster.smtp.SimpleSmtpServer;
import com.dumbster.smtp.SmtpMessage;
import com.dumbster.smtp.SmtpResponse;
import com.dumbster.smtp.SmtpState;
import org.hamcrest.Description;
import org.hamcrest.Factory;
import org.hamcrest.Matcher;
import org.hamcrest.TypeSafeMatcher;

import java.util.Iterator;

public class BodySmtpMessage extends TypeSafeMatcher<Smtpmessage> {
    private SmtpMessage smtpMessage;

    public BodySmtpMessage(SmtpMessage smtpMessage) {
        this.smtpMessage = smtpMessage;
    }

    @Override
    public boolean matchesSafely(SmtpMessage smtpMessage) {
        return smtpMessage.getBody().equals(smtpMessage.getBody());
    }

    @Override
    public void describeTo(Description description) {
        description.appendText("not same body message");
    }

    @Factory
    public static <T> Matcher<smtpmessage> bodyEqualTo(SmtpMessage smtpMessage) {
        return new BodySmtpMessage(smtpMessage);
    }

    public static SmtpMessage getExpectedSmtpMessage(String body) {
        SmtpResponse smtpResponse = new SmtpResponse(1, "", SmtpState.DATA_BODY);
        SmtpMessage expectedMessage = new SmtpMessage();
        expectedMessage.store(smtpResponse, body);

        return expectedMessage;
    }

    public static SmtpMessage getFirstReceivedMessage(SimpleSmtpServer simpleSmtpServer) {
        Iterator<smtpmessage> receivedEmail = simpleSmtpServer.getReceivedEmail();

        while (receivedEmail.hasNext()) {
            return receivedEmail.next();
        }
        return null;
    }
}

4. Junit

import com.dumbster.smtp.SimpleSmtpServer;
import com.dumbster.smtp.SimpleSmtpServer;
import com.dumbster.smtp.SmtpMessage;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import javax.annotation.Resource;

import static au.com.hothouse.toyota.utils.email.BodySmtpMessage.*;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.*;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath*:applicationContext-test.xml")
public class TestEmailerImpl {
    @Resource(name = "saveYourCarEmailer")
    private EmailerImpl emailer;
    @Resource(name = "fakeSmtpServer")
    private SimpleSmtpServer simpleSmtpServer;

    private static String EXPECTED = "Dear Jianjun Shou,\n" +
            "\n" +
            "Here is the permanent link to the vehicle you have created:\n" +
            "\n" +
            "http://test.email.hothouse.com.au\n" +
            "\n" +
            "Thank you for vising the Toyota website.\n" +
            "\n" +
            "Regards,\n" +
            "\n" +
            "The Toyota Team";

    @Test
    public void testEmail() throws Exception {
        emailer.email("Jianjun", "Shou", "sean.shou@hothouse.com.au", "http://test.email.hothouse.com.au");
        assertTrue("test failed", simpleSmtpServer.getReceivedEmailSize() > 0);
        SmtpMessage sentMessage = getFirstReceivedMessage(simpleSmtpServer);
        SmtpMessage expectedSmtpMessage = getExpectedSmtpMessage(EXPECTED);
        assertThat(sentMessage, is(bodyEqualTo(expectedSmtpMessage)));
    }
}