Spring Data MongoDB入门-访问mongodb

在阅读本文前需要以下先决条件

• 电脑上安装了jdk1.7或以上版本

• 安装了maven3以上版本

• 安装了eclipse

1. 在eclipse中创建一个简单的java工程（空白工程即可）并创建以下包结构

   

2. 在项目根目录下创建pom.xml文件，内容如下：

<?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>org.springframework</groupId>
    <artifactId>gs-accessing-data-mongodb</artifactId>
    <version>0.1.0</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.2.5.RELEASE</version>
    </parent>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-mongodb</artifactId>
        </dependency>
    </dependencies>


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

    <repositories>
        <repository>
            <id>spring-releases</id>
            <name>Spring Releases</name>
            <url>https://repo.spring.io/libs-release</url>
        </repository>
    </repositories>
    <pluginRepositories>
        <pluginRepository>
            <id>spring-releases</id>
            <name>Spring Releases</name>
            <url>https://repo.spring.io/libs-release</url>
        </pluginRepository>
    </pluginRepositories>
</project>

3. 创建一个简单的实体，如下：

package hello;

import org.springframework.data.annotation.Id;


public class Customer {

    @Id
    private String id;

    private String firstName;
    private String lastName;

    public Customer() {}

    public Customer(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }

    @Override
    public String toString() {
        return String.format(
                "Customer[id=%s, firstName='%s', lastName='%s']",
                id, firstName, lastName);
    }

}

4. 创建一个仓库类继承自org.springframework.data.mongodb.repository.MongoRepository，如下：

package hello;

import java.util.List;

import org.springframework.data.mongodb.repository.MongoRepository;

public interface CustomerRepository extends MongoRepository<Customer, String> {

    public Customer findByFirstName(String firstName);
    public List<Customer> findByLastName(String lastName);

}

5. 创建一个启动类（或叫测试类），如下：

package hello;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application implements CommandLineRunner {

	@Autowired
	private CustomerRepository repository;

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

	@Override
	public void run(String... args) throws Exception {

		repository.deleteAll();

		// save a couple of customers
		repository.save(new Customer("Alice", "Smith"));
		repository.save(new Customer("Bob", "Smith"));

		// 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);
		}

	}

}

运行这个启动类即可看到测试结果，在测试前记得启动你电脑上的mongodb,如果还没安装mongodb，可以参考我的这篇博客：mongodb安装及启动

本文参考了springdata官网上的这篇文章：Accessing Data with MongoDB， 不是完全翻译。