Spring Boot 2 Recipes

CHAPTER 1. Spring Boot—Introduction

1-3 Create a Spring Boot Application Using Spring Initializr

https://start.spring.io/

CHAPTER 2. Spring Boot—Basics

2-3 Testing

See org.junit.Assert instead of org.assertj.core.api.Assertions: https://junit.org/junit4/javadoc/4.8/org/junit/Assert.html
https://assertj.github.io/doc/

package com.apress.springbootrecipes.calculator.operation;

import org.junit.Test;

import static org.assertj.core.api.Assertions.assertThat;

public class MultiplicationTest {

    private final Multiplication addition = new Multiplication();

    @Test
    public void shouldMatchPlusSign() {
        assertThat(addition.handles('*')).isTrue();
        assertThat(addition.handles('/')).isFalse();
    }

    @Test
    public void shouldCorrectlyApplyFormula() {
        assertThat(addition.apply(2, 2)).isEqualTo(4);
        assertThat(addition.apply(12, 10)).isEqualTo(120);
    }
}

CHAPTER 8. Java Enterprise Services

8-3 Sending E-mail

Sending a Plain Text E-mail

Spring Framework Documentation Integration 6. Email: https://docs.spring.io/spring/docs/5.1.6.RELEASE/spring-framework-reference/integration.html#mail
JavaMailSender: https://docs.spring.io/spring/docs/5.1.6.RELEASE/javadoc-api/org/springframework/mail/javamail/JavaMailSender.html

package com.apress.springbootrecipes.mailsender;

import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;

import javax.mail.Message;

@SpringBootApplication
public class MailSenderApplication {

    public static void main(String[] args) {
        SpringApplication.run(MailSenderApplication.class, args);
    }

    @Bean
    public ApplicationRunner startupMailSender(JavaMailSender mailSender) {
        return (args) -> { mailSender.send((msg) -> {
            var helper = new MimeMessageHelper(msg);
                helper.setTo("recipient@some.where");
                helper.setFrom("spring-boot-2-recipes@apress.com");
                helper.setSubject("Status message");
                helper.setText("All is well.");
            });
        };
    }
}

Using Thymeleaf for E-mail Templates

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org"> <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> </head>
<body>
<p><strong th:text="${msg}">Some email content will be here.</strong></p>
<p>
Kind Regards,
    Your Application
</p>
</body>
</html>

package com.apress.springbootrecipes.mailsender;

import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.context.i18n.LocaleContextHolder;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.thymeleaf.context.Context;
import org.thymeleaf.spring5.SpringTemplateEngine;

import javax.mail.Message;
import java.util.Collections;

@SpringBootApplication
public class MailSenderApplication {

    public static void main(String[] args) {
        SpringApplication.run(MailSenderApplication.class, args);
    }

    @Bean
    public ApplicationRunner startupMailSender(
                JavaMailSender mailSender,
                SpringTemplateEngine templateEngine) {

        return (args) -> {
            mailSender.send((msg) -> {
                var helper = new MimeMessageHelper(msg);
                helper.setTo("recipient@some.where");
                helper.setFrom("spring-boot-2-recipes@apress.com");
                helper.setSubject("Status message");
                var context = new Context(
                    LocaleContextHolder.getLocale(),
                    Collections.singletonMap("msg", "All is well!"));
                var body = templateEngine.process("email.html", context);
                helper.setText(body, true);
            });
        };
    }
}