在Spring Boot中集成Mongodb非常简单，只需要加入Mongodb的Starter包即可，代码如下：

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

然后配置Mongodb的连接信息：

spring.data.mongodb.uri=mongodb://192.168.0.13/test

完整配置信息请参考下面：

spring.data.mongodb.authentication-database= # Authentication database name.
spring.data.mongodb.database= # Database name.
spring.data.mongodb.field-naming-strategy= # Fully qualified name of the FieldNamingStrategy to use.
spring.data.mongodb.grid-fs-database= # GridFS database name.
spring.data.mongodb.host= # Mongo server host. Cannot be set with URI.
spring.data.mongodb.password= # Login password of the mongo server. Cannot be set with URI.
spring.data.mongodb.port= # Mongo server port. Cannot be set with URI.
spring.data.mongodb.repositories.type=auto # Type of Mongo repositories to enable.
spring.data.mongodb.uri=mongodb://localhost/test # Mongo database URI. Cannot be set with host, port and credentials.
spring.data.mongodb.username= # Login user of the mongo server. Cannot be set with URI.

配置好了之后就直接可以注入MongoTemplate操作数据了

添加数据

首先创建一个实体类，我们这边用文章来做实体类，定义如下字段:

import java.util.Date;
import java.util.List;
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;
import org.springframework.data.mongodb.core.mapping.Field;
/**
 * 文章信息
 * @author yinjihuan
 *
 */
@Document(collection = "article_info")
public class Article {
    @Id
    private String id;
    @Field("title")
    private String title;
    @Field("url")
    private String url;
    @Field("author")
    private String author;
    @Field("tags")
    private List<String> tags;
    @Field("visit_count")
    private Long visitCount;
    @Field("add_time")
    private Date addTime;
    
    //省略get set方法
}

实体类中的注解解释如下： 1.Document注解标识这是一个文档，等同mysql中的表,collection值表示mongodb中集合的名称，不写默认为实体类名article。 2.Id注解为主键标识 3.Field注解为字段标识，指定值为字段名称，这边有个小技巧，之所有spring-data.mongodb中有这样的注解，是为了能够让用户自定义字段名称，可以和实体类不一致，还有个好处就是可以用缩写，比如username我们可以配置成unane或者un,这样的好处是节省了存储空间，mongodb的存储方式是key value形式的，每个key就会重复存储，key其实就占了很大一份存储空间。

接下来可以操作数据库了，接着上次，在测试类里写代码

@Autowired
private MongoTemplate mongoTemplate;

/**
 * 初始化文章信息
 * @author yinjihuan
 */
public static void initArticle() {
    //循环添加
    for (int i = 0; i < 10; i++) {
        Article article = new Article();
        article.setTitle("MongoTemplate的基本使用");
	    article.setAuthor("yinjihuan");
	    article.setUrl("http://cxytiandi.com/blog/detail/" + i);
	    article.setTags(Arrays.asList("java", "mongodb", "spring"));
	    article.setVisitCount(0L);
	    article.setAddTime(new Date());
	    mongoTemplate.save(article);
    }
    
    //批量添加
    List<Article> articles = new ArrayList<>(10);
    for (int i = 0; i < 10; i++) {
	    Article article = new Article();
	    article.setTitle("MongoTemplate的基本使用");
	    article.setAuthor("yinjihuan");
	    article.setUrl("http://cxytiandi.com/blog/detail/" + i);
	    article.setTags(Arrays.asList("java", "mongodb", "spring"));
	    article.setVisitCount(0L);
	    article.setAddTime(new Date());
	    articles.add(article);
    }
    mongoTemplate.insert(articles, Article.class);
  
}

在数据量大的情况下批量添加性能会更好哦。

删除操作

//删除author为yinjihuan的数据
Query query = Query.query(Criteria.where("author").is("yinjihuan"));
mongoTemplate.remove(query, Article.class);

//如果实体类中没配集合名词，可在删除的时候单独指定article_info
query = Query.query(Criteria.where("author").is("yinjihuan"));
mongoTemplate.remove(query, "article_info");

//删除集合，可传实体类，也可以传名称
mongoTemplate.dropCollection(Article.class);
mongoTemplate.dropCollection("article_info");

//删除数据库
mongoTemplate.getDb().dropDatabase();

下面这2种适合要知道删除的数据有哪些的场景，比如记录删除的记录

//查询出符合条件的第一个结果，并将符合条件的数据删除,只会删除第一条
query = Query.query(Criteria.where("author").is("yinjihuan"));
Article article = mongoTemplate.findAndRemove(query, Article.class);

//查询出符合条件的所有结果，并将符合条件的所有数据删除
query = Query.query(Criteria.where("author").is("yinjihuan"));
List<Article> articles = mongoTemplate.findAllAndRemove(query, Article.class);

修改操作

首先初始化需要修改的数据

{
    "_id": ObjectId("57c43caed4c63d7e39b5dc48"),
    "title": "MongoTemplate的基本使用",
    "url": "http://cxytiandi.com/blog/detail/0",
    "author": "yinjihuan",
    "tags": [
        "java",
        "mongodb",
        "spring"
    ],
    "visit_count": 0,
    "add_time": ISODate("2016-08-29T13:46:21.881Z")
}
{
    "_id": ObjectId("57c43caed4c63d7e39b5dc49"),
    "title": "MongoTemplate的基本使用",
    "url": "http://cxytiandi.com/blog/detail/1",
    "author": "yinjihuan",
    "tags": [
        "java",
        "mongodb",
        "spring"
    ],
    "visit_count": 0,
    "add_time": ISODate("2016-08-29T13:46:22.201Z")
}

//修改第一条author为yinjihuan的数据中的title和visitCount
Query query = Query.query(Criteria.where("author").is("yinjihuan"));
Update update = Update.update("title", "MongoTemplate").set("visitCount", 10);
mongoTemplate.updateFirst(query, update, Article.class);

修改后结果如下,我们会发现第一条数据的title还有visit_count被修改了

{
    "_id": ObjectId("57c43caed4c63d7e39b5dc48"),
    "title": "MongoTemplate",
    "url": "http://cxytiandi.com/blog/detail/0",
    "author": "yinjihuan",
    "tags": [
        "java",
        "mongodb",
        "spring"
    ],
    "visit_count": 10,
    "add_time": ISODate("2016-08-29T13:46:21.881Z")
}
{
    "_id": ObjectId("57c43caed4c63d7e39b5dc49"),
    "title": "MongoTemplate的基本使用",
    "url": "http://cxytiandi.com/blog/detail/1",
    "author": "yinjihuan",
    "tags": [
        "java",
        "mongodb",
        "spring"
    ],
    "visit_count": 0,
    "add_time": ISODate("2016-08-29T13:46:22.201Z")
}

//修改全部符合条件的
query = Query.query(Criteria.where("author").is("yinjihuan"));
update = Update.update("title", "MongoTemplate").set("visitCount", 10);
mongoTemplate.updateMulti(query, update, Article.class);

修改后结果如下,我们会发现所有数据的title还有visit_count被修改了

{
    "_id": ObjectId("57c43caed4c63d7e39b5dc48"),
    "title": "MongoTemplate",
    "url": "http://cxytiandi.com/blog/detail/0",
    "author": "yinjihuan",
    "tags": [
        "java",
        "mongodb",
        "spring"
    ],
    "visit_count": 10,
    "add_time": ISODate("2016-08-29T13:46:21.881Z")
}
{
    "_id": ObjectId("57c43caed4c63d7e39b5dc49"),
    "title": "MongoTemplate",
    "url": "http://cxytiandi.com/blog/detail/1",
    "author": "yinjihuan",
    "tags": [
        "java",
        "mongodb",
        "spring"
    ],
    "visit_count": 10,
    "add_time": ISODate("2016-08-29T13:46:22.201Z")
}

//特殊更新，更新author为jason的数据，如果没有author为jason的数据则以此条件创建一条新的数据
//当没有符合条件的文档，就以这个条件和更新文档为基础创建一个新的文档，如果找到匹配的文档就正常的更新。
query = Query.query(Criteria.where("author").is("jason"));
update = Update.update("title", "MongoTemplate").set("visitCount", 10);
mongoTemplate.upsert(query, update, Article.class);

修改后结果如下,我们会发现新增了一条数据

{
    "_id": ObjectId("57c43caed4c63d7e39b5dc48"),
    "title": "MongoTemplate",
    "url": "http://cxytiandi.com/blog/detail/0",
    "author": "yinjihuan",
    "tags": [
        "java",
        "mongodb",
        "spring"
    ],
    "visit_count": 10,
    "add_time": ISODate("2016-08-29T13:46:21.881Z")
}
{
    "_id": ObjectId("57c43caed4c63d7e39b5dc49"),
    "title": "MongoTemplate",
    "url": "http://cxytiandi.com/blog/detail/1",
    "author": "yinjihuan",
    "tags": [
        "java",
        "mongodb",
        "spring"
    ],
    "visit_count": 10,
    "add_time": ISODate("2016-08-29T13:46:22.201Z")
}
{
    "_id": ObjectId("57c6e1601e4735b2c306cdb7"),
    "author": "jason",
    "title": "MongoTemplate",
    "visit_count": 10
}

//更新条件不变，更新字段改成了一个我们集合中不存在的，用set方法如果更新的key不存在则创建一个新的key
query = Query.query(Criteria.where("author").is("jason"));
update = Update.update("title", "MongoTemplate").set("money", 100);
mongoTemplate.updateMulti(query, update, Article.class);

修改后结果如下,我们会发现新加了一个key

{
    "_id": ObjectId("57c6e1601e4735b2c306cdb7"),
    "author": "jason",
    "title": "MongoTemplate",
    "visit_count": 10,
    "money":100
}

//update的inc方法用于做累加操作，将money在之前的基础上加上100
query = Query.query(Criteria.where("author").is("jason"));
update = Update.update("title", "MongoTemplate").inc("money", 100);
mongoTemplate.updateMulti(query, update, Article.class);

修改后结果如下,我们会发现money变成200

{
    "_id": ObjectId("57c6e1601e4735b2c306cdb7"),
    "author": "jason",
    "title": "MongoTemplate",
    "visit_count": 10,
    "money":200
}

//update的rename方法用于修改key的名称
query = Query.query(Criteria.where("author").is("jason"));
update = Update.update("title", "MongoTemplate").rename("visitCount", "vc");
mongoTemplate.updateMulti(query, update, Article.class);

{
    "_id": ObjectId("57c6e1601e4735b2c306cdb7"),
    "author": "jason",
    "title": "MongoTemplate",
    "vc": 10,
    "money":200
}

//update的unset方法用于删除key
query = Query.query(Criteria.where("author").is("jason"));
update = Update.update("title", "MongoTemplate").unset("vc");
mongoTemplate.updateMulti(query, update, Article.class);

修改后结果如下,我们会发现vc这个key被删除了

{
    "_id": ObjectId("57c6e1601e4735b2c306cdb7"),
    "author": "jason",
    "title": "MongoTemplate",
    "money":200
}

//update的pull方法用于删除tags数组中的java
query = Query.query(Criteria.where("author").is("yinjihuan"));
update = Update.update("title", "MongoTemplate").pull("tags", "java");
mongoTemplate.updateMulti(query, update, Article.class);

修改后结果如下,我们会发现tags里的java被删除了

{
    "_id": ObjectId("57c43caed4c63d7e39b5dc48"),
    "title": "MongoTemplate",
    "url": "http://cxytiandi.com/blog/detail/0",
    "author": "yinjihuan",
    "tags": [
        "mongodb",
        "spring"
    ],
    "visit_count": 10,
    "add_time": ISODate("2016-08-29T13:46:21.881Z")
}
{
    "_id": ObjectId("57c43caed4c63d7e39b5dc49"),
    "title": "MongoTemplate",
    "url": "http://cxytiandi.com/blog/detail/1",
    "author": "yinjihuan",
    "tags": [
        "mongodb",
        "spring"
    ],
    "visit_count": 10,
    "add_time": ISODate("2016-08-29T13:46:22.201Z")
}

查询操作

查询，无论是关系型数据库还是mongodb这种nosql，都是使用比较多的，大部分操作都是读的操作。 mongodb的查询方式很多种，下面只列了一些常用的，比如： 1.=查询 2.模糊查询 3.大于小于范围查询 4.in查询 5.or查询 6.查询一条，查询全部 7.自己慢慢学习...

根据作者查询所有符合条件的数据，返回List

Query query = Query.query(Criteria.where("author").is("yinjihuan"));
List<Article> articles = mongoTemplate.find(query, Article.class);

只查询符合条件的第一条数据，返回Article对象

query = Query.query(Criteria.where("author").is("yinjihuan"));
Article article = mongoTemplate.findOne(query, Article.class);

查询集合中所有数据，不加条件

articles = mongoTemplate.findAll(Article.class);

查询符合条件的数量

query = Query.query(Criteria.where("author").is("yinjihuan"));
long count = mongoTemplate.count(query, Article.class);

根据主键ID查询

article = mongoTemplate.findById(new ObjectId("57c6e1601e4735b2c306cdb7"), Article.class);

in查询

List<String> authors = Arrays.asList("yinjihuan", "jason");
query = Query.query(Criteria.where("author").in(authors));
articles = mongoTemplate.find(query, Article.class);

ne（!=）查询

query = Query.query(Criteria.where("author").ne("yinjihuan"));
articles = mongoTemplate.find(query, Article.class);

lt(<)查询访问量小于10的文章

query = Query.query(Criteria.where("visitCount").lt(10));
articles = mongoTemplate.find(query, Article.class);

范围查询，大于5小于10

query = Query.query(Criteria.where("visitCount").gt(5).lt(10));
articles = mongoTemplate.find(query, Article.class);

模糊查询，author中包含a的数据

query = Query.query(Criteria.where("author").regex("a"));
articles = mongoTemplate.find(query, Article.class);

数组查询，查询tags里数量为3的数据

query = Query.query(Criteria.where("tags").size(3));
articles = mongoTemplate.find(query, Article.class);

or查询，查询author=jason的或者visitCount=0的数据

query = Query.query(Criteria.where("").orOperator(
    Criteria.where("author").is("jason"),
    Criteria.where("visitCount").is(0)));
articles = mongoTemplate.find(query, Article.class);

更多技术分享请关注微信公众号：猿天地