spring-boot 配置mongoDB连接，保存、查找、统计操作

简单几步，就可以配置好mongoDB的连接，然后使用MongoTemplate操作数据：

1、引入依赖：

		
			org.springframework.boot
			spring-boot-starter-data-mongodb
		

2、application.yml中配置连接信息：

spring:
  data:
    mongodb:
      uri: mongodb://192.168.0.9:27017/test

其中：test是db的名字。

3、创建一个实体类：

package com.xjj.entity;

import java.util.Date;

public class Person {
	private int id;
	private String firstName;
	private String lastName;
	private Date birthDate;
	private char sex;		//'M', 'F'
	private String phoneNo;
	
	public String getFirstName() {
		return firstName;
	}
	public void setFirstName(String firstName) {
		this.firstName = firstName;
	}
	public String getLastName() {
		return lastName;
	}
	public void setLastName(String lastName) {
		this.lastName = lastName;
	}
	public Date getBirthDate() {
		return birthDate;
	}
	public void setBirthDate(Date birthDate) {
		this.birthDate = birthDate;
	}
	public char getSex() {
		return sex;
	}
	public void setSex(char sex) {
		this.sex = sex;
	}
	public String getPhoneNo() {
		return phoneNo;
	}
	public void setPhoneNo(String phoneNo) {
		this.phoneNo = phoneNo;
	}
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
}

4、把实体类存入mongoDB中，然后根据条件获取出来：

	@Autowired
	MongoTemplate mongoTemplate;
	
	@Test
	public void mongoSaveGetTest() throws JsonProcessingException {
		String dbName = mongoTemplate.getDb().getName();
		logger.info("db name: {}", dbName);
		assertThat(dbName, is("test"));
		
		for(int i=3;i<=25;i++){
			Person p = personDAO.getPersonById(i);
			if(p!=null){
				mongoTemplate.save(p);
			}
		}
		
		Criteria c = new Criteria();
		c.and("id").is(3);
		Person gotP = mongoTemplate.findOne(Query.query(c), Person.class);
		logger.debug("p={}", objectMapper.writeValueAsString(gotP));
		assertThat(gotP.getFirstName(), equalTo("七"));
		
		Set collectionNames = mongoTemplate.getDb().getCollectionNames();
		logger.info("colection names: {}", collectionNames);
		assertThat(collectionNames, hasItem("person"));
	}

5、统计：统计性别为“F”的记录中，各种同姓的人员个数

	@Test
	public void mongoAggregationTest() throws JsonProcessingException{
		Criteria c = new Criteria();
		c.and("sex").is("F");
		
		Aggregation aggr = Aggregation.newAggregation(
				Aggregation.match(c),
	            Aggregation.group("lastName").count().as("count")
	    );
		AggregationResults aggrResult = mongoTemplate.aggregate(aggr, "person", BasicDBObject.class);
		if(!aggrResult.getMappedResults().isEmpty()){
			for(BasicDBObject obj : aggrResult.getMappedResults()){
				logger.info("count by first name: {}", objectMapper.writeValueAsString(obj));
			}
		}	
	}

统计结果：

2016-10-27 18:02:11,911:INFO main (MySpringBootApplicationTests.java:111) - count by first name: {"_id":"田","count":1}
2016-10-27 18:02:11,912:INFO main (MySpringBootApplicationTests.java:111) - count by first name: {"_id":"李","count":19}