BAEL-1591: Tagging implementation with MongoDB.

This commit is contained in:
Donato Rimenti 2018-03-19 01:04:33 +01:00
parent 67c0572a90
commit 53ec7a8313
3 changed files with 422 additions and 0 deletions

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package com.baeldung.tagging;
import java.util.List;
/**
* Model for a blog post.
*
* @author Donato Rimenti
*
*/
public class Post {
/**
* Title of the post.
*/
private String title;
/**
* Full article.
*/
private String article;
/**
* Author of the post.
*/
private String author;
/**
* Tags of the post.
*/
private List<String> tags;
/**
* Gets the {@link #title}.
*
* @return the {@link #title}
*/
public String getTitle() {
return title;
}
/**
* Sets the {@link #title}.
*
* @param title
* the new {@link #title}
*/
public void setTitle(String title) {
this.title = title;
}
/**
* Gets the {@link #article}.
*
* @return the {@link #article}
*/
public String getArticle() {
return article;
}
/**
* Sets the {@link #article}.
*
* @param article
* the new {@link #article}
*/
public void setArticle(String article) {
this.article = article;
}
/**
* Gets the {@link #author}.
*
* @return the {@link #author}
*/
public String getAuthor() {
return author;
}
/**
* Sets the {@link #author}.
*
* @param author
* the new {@link #author}
*/
public void setAuthor(String author) {
this.author = author;
}
/**
* Gets the {@link #tags}.
*
* @return the {@link #tags}
*/
public List<String> getTags() {
return tags;
}
/**
* Sets the {@link #tags}.
*
* @param tags
* the new {@link #tags}
*/
public void setTags(List<String> tags) {
this.tags = tags;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((article == null) ? 0 : article.hashCode());
result = prime * result + ((author == null) ? 0 : author.hashCode());
result = prime * result + ((tags == null) ? 0 : tags.hashCode());
result = prime * result + ((title == null) ? 0 : title.hashCode());
return result;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Post other = (Post) obj;
if (article == null) {
if (other.article != null)
return false;
} else if (!article.equals(other.article))
return false;
if (author == null) {
if (other.author != null)
return false;
} else if (!author.equals(other.author))
return false;
if (tags == null) {
if (other.tags != null)
return false;
} else if (!tags.equals(other.tags))
return false;
if (title == null) {
if (other.title != null)
return false;
} else if (!title.equals(other.title))
return false;
return true;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return "Post [title=" + title + ", article=" + article + ", author=" + author + ", tags=" + tags + "]";
}
}

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package com.baeldung.tagging;
import java.io.Closeable;
import java.io.IOException;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.StreamSupport;
import org.bson.Document;
import com.mongodb.MongoClient;
import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.model.Filters;
/**
* Repository used to manage tags for a blog post.
*
* @author Donato Rimenti
*
*/
public class TagRepository implements Closeable {
/**
* Document field which holds the blog tags.
*/
private static final String TAGS_FIELD = "tags";
/**
* The post collection.
*/
private MongoCollection<Document> collection;
/**
* The MongoDB client, stored in a field in order to close it later.
*/
private MongoClient mongoClient;
/**
* Instantiates a new TagRepository by opening the DB connection.
*/
public TagRepository() {
mongoClient = new MongoClient("localhost", 27018);
MongoDatabase database = mongoClient.getDatabase("blog");
collection = database.getCollection("posts");
}
/**
* Returns a list of posts which contains one or more of the tags passed as
* argument.
*
* @param tags
* a list of tags
* @return a list of posts which contains at least one of the tags passed as
* argument
*/
public List<Post> postsWithAtLeastOneTag(String... tags) {
FindIterable<Document> results = collection.find(Filters.in(TAGS_FIELD, tags));
return StreamSupport.stream(results.spliterator(), false).map(TagRepository::documentToPost)
.collect(Collectors.toList());
}
/**
* Returns a list of posts which contains all the tags passed as argument.
*
* @param tags
* a list of tags
* @return a list of posts which contains all the tags passed as argument
*/
public List<Post> postsWithAllTags(String... tags) {
FindIterable<Document> results = collection.find(Filters.all(TAGS_FIELD, tags));
return StreamSupport.stream(results.spliterator(), false).map(TagRepository::documentToPost)
.collect(Collectors.toList());
}
/**
* Returns a list of posts which contains none of the tags passed as
* argument.
*
* @param tags
* a list of tags
* @return a list of posts which contains none of the tags passed as
* argument
*/
public List<Post> postsWithoutTags(String... tags) {
FindIterable<Document> results = collection.find(Filters.nin(TAGS_FIELD, tags));
return StreamSupport.stream(results.spliterator(), false).map(TagRepository::documentToPost)
.collect(Collectors.toList());
}
/**
* Utility method used to map a MongoDB document into a {@link Post}.
*
* @param document
* the document to map
* @return a {@link Post} object equivalent to the document passed as
* argument
*/
@SuppressWarnings("unchecked")
private static Post documentToPost(Document document) {
Post post = new Post();
post.setArticle(document.getString("article"));
post.setAuthor(document.getString("author"));
post.setTitle(document.getString("title"));
post.setTags((List<String>) document.get(TAGS_FIELD));
return post;
}
/*
* (non-Javadoc)
*
* @see java.io.Closeable#close()
*/
@Override
public void close() throws IOException {
mongoClient.close();
}
}

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package com.baeldung.tagging;
import java.io.IOException;
import java.util.List;
import org.junit.Before;
import org.junit.Test;
import org.junit.After;
import org.junit.Assert;
/**
* Test for {@link TagRepository}.
*
* @author Donato Rimenti
*
*/
public class TaggingIntegrationTest {
/**
* Object to test.
*/
private TagRepository repository;
/**
* Sets the test up by instantiating the object to test.
*/
@Before
public void setup() {
repository = new TagRepository();
}
/**
* Tests {@link TagRepository#postsWithAtLeastOneTag(String...)} with 1 tag.
*/
@Test
public void givenTagRepository_whenPostsWithAtLeastOneTagMongoDB_then3Results() {
List<Post> results = repository.postsWithAtLeastOneTag("MongoDB");
results.forEach(System.out::println);
Assert.assertEquals(3, results.size());
results.forEach(post -> {
Assert.assertTrue(post.getTags().contains("MongoDB"));
});
}
/**
* Tests {@link TagRepository#postsWithAtLeastOneTag(String...)} with 2
* tags.
*/
@Test
public void givenTagRepository_whenPostsWithAtLeastOneTagMongoDBJava8_then4Results() {
List<Post> results = repository.postsWithAtLeastOneTag("MongoDB", "Java 8");
results.forEach(System.out::println);
Assert.assertEquals(4, results.size());
results.forEach(post -> {
Assert.assertTrue(post.getTags().contains("MongoDB") || post.getTags().contains("Java 8"));
});
}
/**
* Tests {@link TagRepository#postsWithAllTags(String...)} with 1 tag.
*/
@Test
public void givenTagRepository_whenPostsWithAllTagsMongoDB_then3Results() {
List<Post> results = repository.postsWithAllTags("MongoDB");
results.forEach(System.out::println);
Assert.assertEquals(3, results.size());
results.forEach(post -> {
Assert.assertTrue(post.getTags().contains("MongoDB"));
});
}
/**
* Tests {@link TagRepository#postsWithAllTags(String...)} with 2 tags.
*/
@Test
public void givenTagRepository_whenPostsWithAllTagsMongoDBJava8_then2Results() {
List<Post> results = repository.postsWithAllTags("MongoDB", "Java 8");
results.forEach(System.out::println);
Assert.assertEquals(2, results.size());
results.forEach(post -> {
Assert.assertTrue(post.getTags().contains("MongoDB"));
Assert.assertTrue(post.getTags().contains("Java 8"));
});
}
/**
* Tests {@link TagRepository#postsWithoutTags(String...)} with 1 tag.
*/
@Test
public void givenTagRepository_whenPostsWithoutTagsMongoDB_then1Result() {
List<Post> results = repository.postsWithoutTags("MongoDB");
results.forEach(System.out::println);
Assert.assertEquals(1, results.size());
results.forEach(post -> {
Assert.assertFalse(post.getTags().contains("MongoDB"));
});
}
/**
* Tests {@link TagRepository#postsWithoutTags(String...)} with 2 tags.
*/
@Test
public void givenTagRepository_whenPostsWithoutTagsMongoDBJava8_then0Results() {
List<Post> results = repository.postsWithoutTags("MongoDB", "Java 8");
results.forEach(System.out::println);
Assert.assertEquals(0, results.size());
results.forEach(post -> {
Assert.assertFalse(post.getTags().contains("MongoDB"));
Assert.assertFalse(post.getTags().contains("Java 8"));
});
}
/**
* Cleans up the test by deallocating memory.
*
* @throws IOException
*/
@After
public void teardown() throws IOException {
repository.close();
}
}