SpringBoot整合MongoDB并去掉_class字段

前言：上文介绍了 MongoDB 安装配置以及连接 这篇文章主要介绍使用springboot 整合mongodb实现简单的crud操作

项目介绍

环境版本说明

MongoDB：5.0.6
SpringBoot：2.5.3
JDK：1.8

本文测试使用了 Swagger的增强工具knife4j 直接进行测试

项目结构

后面会给出项目的全部源代码

代码详情

MongoDB 新建数据库设置用户名密码

use java_test
db.createUser({user:"king",pwd:"123456",roles:[{role:"dbOwner",db:"java_test"}]})

pom.xml文件新增依赖项

        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-data-mongodbartifactId>
            <version>2.6.3version>
        dependency>

MongoConfig.java 配置文件

package com.king.other.config;

import com.mongodb.MongoClientSettings;
import com.mongodb.MongoCredential;
import com.mongodb.ServerAddress;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.config.AbstractMongoClientConfiguration;

import java.util.ArrayList;
import java.util.List;

@Configuration
public class MongoConfig extends AbstractMongoClientConfiguration {

    @Override
    public String getDatabaseName() {
        return "java_test";//数据库名
    }

    @Override
    protected void configureClientSettings(MongoClientSettings.Builder builder) {
        List<ServerAddress> hosts = new ArrayList<>();
        //参数为 数据库地址 端口号有多个可以添加
        hosts.add(new ServerAddress("127.0.0.1", 27017));
        //参数为 用户名 数据库名 数据库密码
        builder.credential(MongoCredential.createCredential("king", getDatabaseName(), "123456".toCharArray()))
                .applyToClusterSettings(settings -> {
                    settings.hosts(hosts);
                });
    }

}

MongoDao.java

package com.king.other.dao;

import com.king.other.entity.Person;
import com.king.other.vo.Result;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.data.mongodb.core.query.Update;
import org.springframework.stereotype.Component;

import java.util.List;

@Component
public class MongoDao {
    @Autowired
    private MongoTemplate mongoTemplate;


    /**
     * 创建对象
     *
     * @return
     */
    public Person save(Person person) {
        return mongoTemplate.save(person);
    }

    /**
     * 根据用户名查询对象
     *
     * @return
     */
    public List<Person> findByName(String name) {
        Query query = new Query(Criteria.where("name").is(name));
        return mongoTemplate.find(query, Person.class);
    }

    public Person findById(Integer id) {
        Query query = new Query(Criteria.where("id").is(id));
        return mongoTemplate.findOne(query, Person.class);
    }

    /**
     * 更新对象
     *
     * @return
     */
    public Person updateById(Person person) {
        Query query = new Query(Criteria.where("id").is(person.getId()));
        Update update = new Update().set("age", person.getAge()).set("name", person.getName());
        //更新查询返回结果集的第一条
        mongoTemplate.updateFirst(query, update, Person.class);
        //更新查询返回结果集的所有
        return findById(person.getId());
    }

    /**
     * 删除对象
     *
     * @param id
     */
    public boolean deleteById(Integer id) {
        boolean b = false;
        try {
            Query query = new Query(Criteria.where("id").is(id));
            b = mongoTemplate.remove(query, Person.class).wasAcknowledged();
        } catch (Exception e) {
            return false;
        }

        return b;
    }

}

MongoController.java

package com.king.other.controller;

import com.king.other.dao.MongoDao;
import com.king.other.entity.Person;
import com.king.other.vo.Result;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.ArrayList;
import java.util.List;


@RestController
@RequestMapping("/mongo")
@Api(value = "mongodb测试接口", tags = "mongodb测试接口")
public class MongoController {

    @Autowired
    private MongoDao mongoDao;

    @GetMapping(value = "/save.do")
    @ApiOperation(value = "新增", tags = "mongodb测试接口")
    public Person save(String name, Integer age) {
        return mongoDao.save(new Person(name, age));
    }

    @GetMapping(value = "/findByName.do")
    @ApiOperation(value = "查询", tags = "mongodb测试接口")
    public Result findByName(String name) {
        Result result = new Result();
        List<Person> list = mongoDao.findByName(name);
        result.setData(list);
        result.setMessage("查询结果");
        result.setStatus(true);
        result.setCount(list.size());
        return result;
    }

    @GetMapping(value = "/updateById.do")
    @ApiOperation(value = "修改", tags = "mongodb测试接口")
    public Person updateById(Integer id, String name, Integer age) {
        Person person = new Person(id, name, age);
        return mongoDao.updateById(person);
    }

    @GetMapping(value = "/deleteById.do")
    @ApiOperation(value = "删除", tags = "mongodb测试接口")
    public Boolean deleteById(Integer id) {
        return mongoDao.deleteById(id);
    }

}

Person.java

package com.king.other.entity;

import lombok.Data;

import java.util.Random;

/**
 * @program: springboot
 * @description:
 * @author: King
 * @create: 2022-02-12 00:38
 */
@Data
public class Person {

    private Integer id;
    private String name;
    private Integer age;

    public Person(String name, int age) {
        this.id = new Random().nextInt();
        this.name = name;
        this.age = age;
    }

    public Person() {
    }

    public Person(Integer id, String name, Integer age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }

    @Override
    public String toString() {
        return "Person [id=" + id + ", name=" + name + ", age=" + age + "]";
    }

}

部分测试截图

这里就实现了对MongoDB简单的crud操作

去掉_class字段

当去数据库看是发现会多出一个_class字段这很难受

只需要给 MongoConfig.java 中加入如下代码即可

    @Bean
    public MappingMongoConverter mappingMongoConverter(MongoDatabaseFactory databaseFactory,MongoCustomConversions customConversions, MongoMappingContext mappingContext){
        MappingMongoConverter mmc = super.mappingMongoConverter(databaseFactory,customConversions,mappingContext);
        mmc.setTypeMapper(defaultMongoTypeMapper());
        return mmc;
    }

    @Bean
    public MongoTypeMapper defaultMongoTypeMapper() {
        return new DefaultMongoTypeMapper(null);
    }

然后我们删掉这个集合

db.person.drop()

再插入几条数据 那烦人的 _class 字段就没了 非常好用

最后附带源码地址

[Github]：(https://github.com/KingJin-web/springboot/tree/master/other)
[Gitee]：(https://gitee.com/KingJin-web/springboot/tree/master/other)