Spring Boot Hands-on Lab

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>fr.insalyon.tc</groupId>
	<artifactId>spring-boot-hol</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>spring-boot-hol</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.6.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId> (1)
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-actuator</artifactId> (2)
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId> (3)
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId> (4)
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>


</project>

./mvnw spring-boot:run

[...]

2018-02-27 14:52:41.278  INFO 4247 --- [  restartedMain] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2018-02-27 14:52:41.283  INFO 4247 --- [  restartedMain] f.i.t.s.SpringBootHolApplication       : Started SpringBootHolApplication in 2.665 seconds (JVM running for 2.968)

$ curl http://localhost:8080/ (1)
{"timestamp":1519739778651,"status":404,"error":"Not Found","message":"No message available","path":"/"}% (2)

<!-- Insert this snippet in the dependencies section -->
<dependency>
  <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-mongodb</artifactId> (1)
</dependency>
<dependency>
  <groupId>de.flapdoodle.embed</groupId>
  <artifactId>de.flapdoodle.embed.mongo</artifactId> (2)
</dependency>

package fr.insalyon.tc.springboothol;

import java.net.URI;
import java.time.LocalDateTime;

import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.index.Indexed;
import org.springframework.data.mongodb.core.mapping.Document;

@Document (1)
public class ShortURL { (2)

	@Id (3)
	private String id;

	private URI uri; (4)

	@Indexed(unique = true)
	private String shortCode; (5)

	private LocalDateTime creationDate; (6)

	public ShortURL() {
	}

	public ShortURL(URI uri, String shortCode) {
		this.uri = uri;
		this.shortCode = shortCode;
		this.creationDate = LocalDateTime.now();
	}

	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public URI getUri() {
		return uri;
	}

	public void setUri(URI uri) {
		this.uri = uri;
	}

	public String getShortCode() {
		return shortCode;
	}

	public void setShortCode(String shortCode) {
		this.shortCode = shortCode;
	}

	public LocalDateTime getCreationDate() {
		return creationDate;
	}

	public void setCreationDate(LocalDateTime creationDate) {
		this.creationDate = creationDate;
	}

	@Override
	public String toString() {
		return "ShortURL{" +
				"id='" + id + '\'' +
				", uri=" + uri +
				", shortCode='" + shortCode + '\'' +
				", creationDate=" + creationDate +
				'}';
	}
}

package fr.insalyon.tc.springboothol;

import java.util.Optional; (1)

import org.springframework.data.repository.CrudRepository; (2)

public interface ShortURLRepository extends CrudRepository<ShortURL, String> { (3)

  // add custom methods here (4)
}

package fr.insalyon.tc.springboothol;

import java.net.URI;
import java.util.Arrays;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.stereotype.Component;

@Component
public class RepositorySample implements ApplicationRunner {

  private final Logger logger = LoggerFactory.getLogger(RepositorySample.class);


  @Override
  public void run(ApplicationArguments args) throws Exception {
    // TODO:
    // 1) create a few ShortURL objects
    // 2) persist them using the repository
    // 3) find all ShortURLs in the database
    // 4) log them using the logger
	}

}

f.i.t.springboothol.RepositorySample   : short URLS :[ShortURL{id='5a987db3adf0cc26e92778ca', uri=https://spring.io/blog, shortCode='spring', creationDate=2018-03-01T23:24:51.837}, ShortURL{id='5a987db3adf0cc26e92778cb', uri=https://www.qwant.com/?q=spring%20boot&t=all, shortCode='search', creationDate=2018-03-01T23:24:51.837}, ShortURL{id='5a987db3adf0cc26e92778cc', uri=https://moodle.insa-lyon.fr, shortCode='moo', creationDate=2018-03-01T23:24:51.837}]

package fr.insalyon.tc.springboothol;

import java.net.URI; (1)
import java.util.Random;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.Assert;

public class ShortURLService {

	private static final String SPACE = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_"; (2)

	private static final int BASE = SPACE.length();

	/**
	 * Create a new {@link ShortURL} using the given URI and save it
	 * in a datastore. The {@code shortCode} used to identify this
	 * URI should be randomly selected.
	 * @param uri the URI to shorten
	 * @return the shortened URL information
	 */
	public ShortURL shortenURL(URI uri) {
		// TODO: create a ShortURL using a random positive integer
		// use java.util.Random and java.lang.Math for that
    // then use that random number with the provided encode method
		// Once created, persist that ShortURL into our database
	}

	/**
	 * Return the {@link ShortURL} information for the given
	 * {code shortCode}, if it exists in the datastore.
	 * @param shortCode the shortened URL code to look for
	 * @return the ShortURL information for the given shortCode
	 * @throws ShortCodeNotFoundException if no ShortURL could be found
	 * for the given shortCode
	 */
	public ShortURL expandShortCode(String shortCode) {
		// TODO: find a ShortURL by its shortcode in the database and return it (3)
		// if there's none, throw a ShortCodeNotFoundException
	}

	private static String encode(int num) { (4)
		Assert.isTrue(num > 0, "Number must be positive");
		StringBuilder str = new StringBuilder();
		while (num > 0) {
			str.insert(0, SPACE.charAt(num % BASE));
			num = num / BASE;
		}
		return str.toString();
	}

}

package fr.insalyon.tc.springboothol;

public class ShortCodeNotFoundException extends RuntimeException {

	private final String shortCode;

	public ShortCodeNotFoundException(String shortCode) {
		super(String.format("Could not find ShortURL for [%s]", shortCode));
		this.shortCode = shortCode;
	}

	public String getShortCode() {
		return shortCode;
	}
}

package fr.insalyon.tc.springboothol;


import java.net.URI;
import java.util.Optional;

import org.hamcrest.Matchers;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;
import org.mockito.Mock;

import static org.assertj.core.api.Assertions.assertThat;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.eq;
import static org.mockito.BDDMockito.given;
import static org.mockito.Mockito.doAnswer;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.MockitoAnnotations.initMocks;

public class ShortURLServiceTests {

	@Rule
	public ExpectedException thrown = ExpectedException.none();

	@Mock
	private ShortURLRepository repository;

	private ShortURLService shortURLService;

	@Before
	public void setup() {
		initMocks(this);
		this.shortURLService = new ShortURLService(this.repository);
		doAnswer(invocation -> invocation.getArgument(0)).when(this.repository).save(any());
	}

	@Test
	public void canShortenURLs() {
		URI uri = URI.create("http://example.org/resource");
		ShortURL shortURL = this.shortURLService.shortenURL(uri);
		assertThat(shortURL.getShortCode()).isNotBlank();
		assertThat(shortURL.getUri()).isEqualTo(uri);
		verify(this.repository, times(1)).save(any());
	}

	@Test
	public void canExpandShortCodes() {
		URI uri = URI.create("http://example.org/resource");
		ShortURL shortURL = new ShortURL(uri, "spring");
		given(this.repository.findByShortCode("spring")).willReturn(Optional.of(shortURL));
		ShortURL result = this.shortURLService.expandShortCode("spring");
		assertThat(result.getUri()).isEqualTo(uri);
		assertThat(result.getShortCode()).isEqualTo("spring");
		verify(this.repository, times(1)).findByShortCode(eq("spring"));
	}

	@Test
	public void unknownShortCode() {
		given(this.repository.findByShortCode("spring")).willReturn(Optional.empty());
		this.thrown.expect(ShortCodeNotFoundException.class);
		this.thrown.expect(Matchers.hasProperty("shortCode", Matchers.equalTo("spring")));
		ShortURL result = this.shortURLService.expandShortCode("spring");
	}

}

package fr.insalyon.tc.springboothol;


import java.net.URI;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.mvc.method.annotation.MvcUriComponentsBuilder;

import static org.springframework.web.servlet.mvc.method.annotation.MvcUriComponentsBuilder.on;

@Controller (1)
public class ShortURLController {

private final ShortURLService shortURLService;

	@Autowired
	public ShortURLController(ShortURLService shortURLService) { (2)
	this.shortURLService = shortURLService;
	}

	@PostMapping("/") (3)
	public ResponseEntity shortenURL(@RequestParam URI uri) { (4)
		ShortURL shortURL = this.shortURLService.shortenURL(uri);
		URI shortenedURL = URI.create("http://localhost:8080/" + shortURL.getShortCode());
		// the host information is hard coded here for simplicity
		// but you can do better with MvcUriComponentsBuilder::fromMethodCall
		return ResponseEntity.created(shortenedURL).build(); (5)
	}

}

$ curl -d uri=http://example.org http://localhost:8080/ -v

> POST / HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.54.0
> Accept: */*
> Content-Length: 22
> Content-Type: application/x-www-form-urlencoded
>
* upload completely sent off: 22 out of 22 bytes
< HTTP/1.1 201
< Location: http://localhost:8080/1giL2D
< Content-Length: 0
<