MongoDb学习笔记（二）SpringBoot整合，client初始化

项目地址：https://gitee.com/xiiiao/mongo-learning

添加pom依赖

<parent>
		<groupId>org.springframework.bootgroupId>
		<artifactId>spring-boot-starter-parentartifactId>
		<version>2.3.1.RELEASEversion>
		<relativePath/> 
parent>

		<dependency>
			<groupId>org.springframework.bootgroupId>
			<artifactId>spring-boot-starter-data-mongodbartifactId>
		dependency>

此依赖基于mongodb-driver 4.0.4，spring-data-mongo-3.0.1，如果需要自行查看相关官方文档，请确定文档版本一致。

创建客户端

可以通过spring的工厂类MongoClientFactoryBean或者mongo提供的工具类MongoClients来创建客户端实例

MongoClientFactoryBean

public @Bean
    MongoClientFactoryBean mongo() {
        MongoClientFactoryBean mongo = new MongoClientFactoryBean();
        MongoCredential credential=MongoCredential.createCredential(mongoSettings.getUsername(),mongoSettings.getDb(),mongoSettings.getPass().toCharArray());
        //can not add credential in this way
        MongoClientSettings setting=MongoClientSettings.builder()
                .credential(credential)
                .build();
                //        mongo.setMongoClientSettings(setting);
        mongo.setHost(mongoSettings.getIpAddress());
        mongo.setPort(mongoSettings.getPort());
        mongo.setCredential(new MongoCredential[]{credential});
        return mongo;
    }

需要注意的是，通过MongoClientFactoryBean来创建实例，mongo认证信息需要通过setCredential方法来设置，setMongoClientSettings方法设置不会生效。

MongoClients

@Bean
    public  MongoClient rawClient(){
        MongoCredential credential=MongoCredential.createCredential(mongoSettings.getUsername(),mongoSettings.getDb(),mongoSettings.getPass().toCharArray());
//        ConnectionString connectionString = new ConnectionString("mongodb://localhost:27017");
        MongoClientSettings setting=MongoClientSettings.builder()
                .credential(credential)
//                .applyConnectionString(connectionString)
                .applyToClusterSettings(builder ->
                        builder.hosts(Arrays.asList(new ServerAddress(mongoSettings.getIpAddress(), mongoSettings.getPort())))
                        .mode(ClusterConnectionMode.SINGLE)
                        .requiredClusterType(ClusterType.STANDALONE)
                ).build();
        return MongoClients.create(setting);
    }

两种方式任选其一即可，完成后就可以通过@Autowired注解在项目中引入MongoClient进行相关操作。

验证配置

在完成初始化之后，可以编写单元测试来简单验证客户端的功能。
先通过mongoShell插入数据

db.foo.insert(
   [
     { _id: 1, name: "Java Hut", description: "Coffee and cakes" },
     { _id: 2, name: "Burger Buns", description: "Gourmet hamburgers" },
     { _id: 3, name: "Coffee Shop", description: "Just coffee" },
     { _id: 4, name: "Clothes Clothes Clothes", description: "Discount clothing" },
     { _id: 5, name: "Java Shopping", description: "Indonesian goods" }
   ]
)

然后编写如下单元测试

	@Autowired
    MongoClient client;

Consumer<Document> printConsumer = new Consumer<Document>() {
        @Override
        public void accept(final Document document) {
            log.info(document.toJson());
        }
    };
	@Test
    void testRawCollections() {
        MongoCollection<Document> collection=client.getDatabase("test").getCollection("foo");
        log.info(collection.countDocuments());
        FindIterable<Document> iterabl=collection.find();
        iterabl.forEach(printConsumer);
    }

一些顺利的话，可以在控制台看到如下日志

2020-08-11 15:47:10.773  INFO 13604 --- [           main] mongo.ClientTest                         : 5
2020-08-11 15:47:10.970  INFO 13604 --- [           main] mongo.ClientTest                         : {"_id": 1.0, "name": "Java Hut", "description": "Coffee and cakes"}
2020-08-11 15:47:10.970  INFO 13604 --- [           main] mongo.ClientTest                         : {"_id": 2.0, "name": "Burger Buns", "description": "Gourmet hamburgers"}
2020-08-11 15:47:10.970  INFO 13604 --- [           main] mongo.ClientTest                         : {"_id": 3.0, "name": "Coffee Shop", "description": "Just coffee"}
2020-08-11 15:47:10.971  INFO 13604 --- [           main] mongo.ClientTest                         : {"_id": 4.0, "name": "Clothes Clothes Clothes", "description": "Discount clothing"}
2020-08-11 15:47:10.971  INFO 13604 --- [           main] mongo.ClientTest                         : {"_id": 5.0, "name": "Java Shopping", "description": "Indonesian goods"}

除mongo原生客户端MongoClient外，sping还提供了mongoTemplate工具类，后续介绍都会通过这两个类进行，并提供相关对比

后话

在学习mongo时，一个好用的客户端工具也很重要，这里参考了别人使用的NoSqlBooster，有免费版，大家可以自行去官网下载。
另外在通过原生的objectId进行查询时，需要通过如下方式，不然什么都查不到，这里被卡了好几次，经常会忘

db.topicOption.find({"_id":ObjectId("5f8d88495f11166b5542e06f")})