实战：在SpringBoot中使用MongoDB

红太狼 2022-04-23 05:50 212阅读 0赞

## 前言 ##

> MongoDB基础教程： [MongoDB教程合集][MongoDB]    [MongoDB教程（易百教程）][MongoDB 1]
> 
> spring-data-mongodb注解：   [Spring中MongoDB注解概念及使用][Spring_MongoDB]

**一、pom.xml依赖配置**

<?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>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.1.2.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>com.scb</groupId>
        <artifactId>mongo-demo</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>mongo-demo</name>
        <description>Demo project for Spring Boot</description>
    
        <properties>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-mongodb</artifactId>
            </dependency>
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>1.2.39</version>
            </dependency>
            <dependency>
                <groupId>ch.qos.logback</groupId>
                <artifactId>logback-classic</artifactId>
                <version>1.1.11</version>
            </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>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    </project>

**二、在application.yml配置文件中配置如下信息**

spring:
      data:
        mongodb:
          host: localhost
          port: 27017
           #MongoDB的数据库名
          database: springboot

**三、创建实体类**

package com.scb.mongodemo.entity;
    
    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;
    
    import java.io.Serializable;
    
    @Data
    @Document
    public class Role implements Serializable {
        private static final long serialVersionUID = -7111768727538023614L;
    
        @Id
        private Long id;
    
        @Field("role_name")
        private String roleName;
    
        @Field("note")
        private String note;
    }

package com.scb.mongodemo.entity;
    
    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;
    
    import java.io.Serializable;
    import java.util.List;
    
    @Data
    @Document
    public class User implements Serializable {
        private static final long serialVersionUID = -2222439945682451664L;
    
        @Id
        private Long id;
    
        @Field("user_name")
        private String userName;
    
        @Field("note")
        private String note;
    
        @Field("roles")
        private List<Role> roles;
    }

**四、使用MongoRepository实现DAO层操作**

package com.scb.mongodemo.repository;
    
    import com.scb.mongodemo.entity.User;
    import org.springframework.data.mongodb.repository.MongoRepository;
    import org.springframework.stereotype.Repository;
    
    import java.util.List;
    
    @Repository
    public interface UserRepository extends MongoRepository<User,Long> {
        List<User> findByUserNameLike(String userName);
    }

注：MongoDB是一个十分接近于关系数据库的NoSQL数据库，因此，它也允许我们使用JPA编程。

有关JPA编程学习的文章：[Spring Data JPA学习导引][Spring Data JPA]

**五、控制层**

package com.scb.mongodemo.controller;
    
    import com.scb.mongodemo.entity.Role;
    import com.scb.mongodemo.entity.User;
    import com.scb.mongodemo.repository.UserRepository;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.*;
    
    import java.util.*;
    
    @RestController
    @RequestMapping("/user")
    public class UserController {
        @Autowired
        UserRepository userRepository;
    
        @GetMapping("/{userName}")
        public List<User> findByUserName(@PathVariable String userName) {
            return userRepository.findByUserNameLike(userName);
        }
    
        @PostMapping("/initUsers")
        public List<User> initUsers(){
            List<User> saveUsers=new ArrayList<>();
            for (int i=1;i<=10;i++){
                User user=new User();
                user.setId((long)i);
                user.setUserName("user_name_"+i);
                user.setNote("user_note_"+i);
    
                Role role=new Role();
                role.setId((long)i);
                role.setRoleName("role_name_"+i);
                role.setNote("role_note_"+i);
                List<Role> roles=new ArrayList<>();
                roles.add(role);
                user.setRoles(roles);
    
                saveUsers.add(userRepository.save(user));
            }
            return saveUsers;
        }
    }

这里因为是测试使用的缘故，就不实现service层了，直接使用UserRepository进行操作。

**六、运行测试**

注：在运行项目时候，要记得打开MongoDB的服务端。

使用Postman测试工具，以post方式访问 localhost:8080/user/initUsers

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NzcxNDc1_size_16_color_FFFFFF_t_70][]

可以看到数据已经插入成功了。在使用Robo 3T客户端软件查看数据（当然也使用命令行），发现多了个"\_class"属性，这是用来反序列化时候使用的。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3NzcxNDc1_size_16_color_FFFFFF_t_70 1][]

[MongoDB]: https://blog.csdn.net/u012702547/article/details/83275695
[MongoDB 1]: https://www.yiibai.com/mongodb
[Spring_MongoDB]: https://www.cnblogs.com/liuchuanfeng/p/7772421.html
[Spring Data JPA]: https://blog.csdn.net/qq_37771475/article/details/86299737
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