Springboot集成MongoDB
简介 MongoDB（来自于英文单词“Humongous”，中文含义为“庞大”）是可以应用于各种规模的企业、各个行业以及各类应用程序的开源数据库。作为一个适用于敏捷开发的数据库，MongoDB的数据模式可以随着应用程序的发展而灵活地更新。与此同时，它也为开发人员 提供了传统数据库的功能：二级索引，完整的查询系统以及严格一致性等等。 MongoDB能够使企业更加具有敏捷性和可扩展性，各种规模的企业都可以通过使用MongoDB来创建新的应用，提高与客户之间的工作效率，加快产品上市时间，以及降低企业成本。 安装mongoDB https://www.cnblogs.com/woshimrf/p/linux-install-mongodb.html 创建项目 https://github.com/Ryan-Miao/springboot-with-mongodb pom <?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>com.test</groupId> <artifactId>springboot-with-mongodb</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>springboot-with-mongodb</name> <description>Demo project for Spring Boot</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.2.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-data-mongodb</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>io.springfox</groupId> <artifactId>springfox-swagger2</artifactId> <version>2.7.0</version> </dependency> <dependency> <groupId>io.springfox</groupId> <artifactId>springfox-swagger-ui</artifactId> <version>2.7.0</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project> 配置文件 spring.data.mongodb.uri=mongodb://localhost:27017/demo 创建一个表/集合 一个消费者 @Data public class Customer { @Id public String id; public String firstName; public String lastName; private List<Hobby> hobbies; public Customer() { } public Customer(String firstName, String lastName, List<Hobby> hobbies) { this.firstName = firstName; this.lastName = lastName; this.hobbies = hobbies; } } import org.springframework.data.annotation.Id; 是mongodb里的主键 创建Repository JPA的一个特性就是简化了CRUD, 通过解析方法名实现数据的传输 import com.test.springbootwithmongodb.entity.Customer; import java.util.List; import org.springframework.data.mongodb.repository.MongoRepository; public interface CustomerRepository extends MongoRepository<Customer, String> { Customer findByFirstName(String firstName); List<Customer> findByLastName(String lastName); } 方法名findBy字段名即可实现查询。 启动并测试 @SpringBootApplication public class SpringbootWithMongodbApplication implements CommandLineRunner { private final CustomerRepository repository; private final BookRepository bookRepository; private final AuthorRepository authorRepository; @Autowired public SpringbootWithMongodbApplication(CustomerRepository repository, BookRepository bookRepository, AuthorRepository authorRepository) { this.repository = repository; this.bookRepository = bookRepository; this.authorRepository = authorRepository; } public static void main(String[] args) { SpringApplication.run(SpringbootWithMongodbApplication.class, args); } @Override public void run(String... args) { repository.deleteAll(); // save a couple of customers repository.save(new Customer("Alice", "Smith", Lists.newArrayList(new Hobby("读书", 1), new Hobby("看电影", 2)))); repository.save(new Customer("Bob", "Smith", Lists.newArrayList())); // fetch all customers System.out.println("Customers found with findAll():"); System.out.println("-------------------------------"); for (Customer customer : repository.findAll()) { System.out.println(customer); } System.out.println(); // fetch an individual customer System.out.println("Customer found with findByFirstName('Alice'):"); System.out.println("--------------------------------"); System.out.println(repository.findByFirstName("Alice")); System.out.println("Customers found with findByLastName('Smith'):"); System.out.println("--------------------------------"); for (Customer customer : repository.findByLastName("Smith")) { System.out.println(customer); } } } 至此，hello world完成。基本实现了mongoDB持久层的工作，只要继续深入开发即可。 关联表 创建一个书籍的集合 import java.time.LocalDate; import lombok.Data; import org.springframework.data.annotation.Id; import org.springframework.data.mongodb.core.mapping.Document; import org.springframework.data.mongodb.core.mapping.Field; @Data @Document(collection = "books") public class Book { @Id private String id; private String title; @Field("published") private LocalDate publicationDate; // No args Constructor public Book(String title, LocalDate publicationDate) { this.title = title; this.publicationDate = publicationDate; } } @Field指定数据库映射的字段 @Transient标注的字段则不会映射到db @Document(collection = "books")可以指定集合名称，如果不指定则是类名首字母小写 创建一个作者，作者拥有书籍 @Data public class Author { @Id private ObjectId id; @Indexed(unique = true) private String name; @DBRef private Set<Book> books; // No args Constructor public Author(String name) { this.name = name; } } @DBRef会引用books的表 @Indexed(unique = true)设置索引，并且是唯一性索引 CRUD 暂时不自定义查询了，利用内置的查询即可 public interface AuthorRepository extends MongoRepository<Author, ObjectId> { } public interface BookRepository extends MongoRepository<Book, ObjectId> { } 测试 bookRepository.deleteAll(); authorRepository.deleteAll(); Book ci = new Book("Continous Integration", LocalDate.now()); // id will be generated after save bookRepository.save(ci); Book c2 = new Book("Java编程思想", LocalDate.now()); Book c3 = new Book("Java核心技术", LocalDate.now()); Book c4 = new Book("Effective Java", LocalDate.now()); Book c5 = new Book("深入理解虚拟机", LocalDate.now()); Book c6 = new Book("深入理解虚拟机", LocalDate.now()); bookRepository.save(c2); bookRepository.save(c3); bookRepository.save(c4); bookRepository.save(c5); bookRepository.save(c6); List<Book> books = bookRepository.findAll(); System.out.println(books); Author julius = new Author("Julius"); julius.setBooks(Stream.of(ci, c2, c3, c4, c5, c6).collect(Collectors.toSet())); authorRepository.save(julius); System.out.println(authorRepository.findAll()); 启动可以看到控制台输出： [Book(id=5b0bec767a49d017f0e46c63, title=Continous Integration, publicationDate=2018-05-28), Book(id=5b0bec767a49d017f0e46c64, title=Java编程思想, publicationDate=2018-05-28), Book(id=5b0bec767a49d017f0e46c65, title=Java核心技术, publicationDate=2018-05-28), Book(id=5b0bec767a49d017f0e46c66, title=Effective Java, publicationDate=2018-05-28), Book(id=5b0bec767a49d017f0e46c67, title=深入理解虚拟机, publicationDate=2018-05-28), Book(id=5b0bec767a49d017f0e46c68, title=深入理解虚拟机, publicationDate=2018-05-28)] [Author(id=5b0bec767a49d017f0e46c69, name=Julius, books=[Book(id=5b0bec767a49d017f0e46c64, title=Java编程思想, publicationDate=2018-05-28), Book(id=5b0bec767a49d017f0e46c68, title=深入理解虚拟机, publicationDate=2018-05-28), Book(id=5b0bec767a49d017f0e46c67, title=深入理解虚拟机, publicationDate=2018-05-28), Book(id=5b0bec767a49d017f0e46c63, title=Continous Integration, publicationDate=2018-05-28), Book(id=5b0bec767a49d017f0e46c65, title=Java核心技术, publicationDate=2018-05-28), Book(id=5b0bec767a49d017f0e46c66, title=Effective Java, publicationDate=2018-05-28)])] 连接db，查询 db.author.find({}) { "_id" : ObjectId("5b0bec767a49d017f0e46c69"), "name" : "Julius", "books" : [ DBRef("books", ObjectId("5b0bec767a49d017f0e46c64")), DBRef("books", ObjectId("5b0bec767a49d017f0e46c68")), DBRef("books", ObjectId("5b0bec767a49d017f0e46c67")), DBRef("books", ObjectId("5b0bec767a49d017f0e46c63")), DBRef("books", ObjectId("5b0bec767a49d017f0e46c65")), DBRef("books", ObjectId("5b0bec767a49d017f0e46c66")) ], "_class" : "com.test.springbootwithmongodb.entity.Author" } MongoTemplate 可以自己注入MongoTemplate来实现更多操作, 比如 private final MongoTemplate mongoTemplate; List<Customer> list = mongoTemplate.findAll(Customer.class); 索引 还可以这样设置联合索引 @Document @CompoundIndexes({ @CompoundIndex(name = "email_age", def = "{'email.id' : 1, 'age': 1}") }) public class User { // } 查询索引 db.user.getIndexes(); { "v" : 1, "key" : { "email.id" : 1, "age" : 1 }, "name" : "email_age", "ns" : "test.user" } 关注我的公众号 唯有不断学习方能改变！ -- Ryan Miao
