Spring Boot MongoDB

1.  Linux下启动MongoDB并使用mongosh连接

启动方式有两种：

• systemctl start mongod
• mongod  <选项参数>

启动的时候有可能会报类似如下的错误：

ExecStart=/usr/bin/mongod $OPTIONS (code=exited, status=14)

mongod.service: Control process exited, code=exited status=14

当看到这种“code=exited, status=14”的时候，一般是文件或目录权限问题，即执行mongodb启动命令的用户对某些文件或目录没有访问权限，此时应检查一些几个文件或目录：

• /var/run/mongodb/
• /var/log/mongodb/
• /var/lib/mongo/
• /tmp @Data @NoArgsConstructor @AllArgsConstructor @Document(collection = "film") public class Film implements Serializable { @Id private String id; private String name; private List category; }

  然后，利用MongoTemplate进行操作

  package com.cjs.example;
  
  import com.cjs.example.domain.Film;
  import com.cjs.example.repository.FilmRepository;
  import org.junit.jupiter.api.Test;
  import org.springframework.boot.test.context.SpringBootTest;
  import org.springframework.data.mongodb.core.MongoTemplate;
  import org.springframework.data.mongodb.core.query.Criteria;
  import org.springframework.data.mongodb.core.query.Query;
  
  import javax.annotation.Resource;
  import java.util.Arrays;
  import java.util.List;
  
  @SpringBootTest
  class DemoMongodbApplicationTests {
  
      @Resource
      private MongoTemplate mongoTemplate;
  
  
      
      @Test
      void contextLoads() {
          Film film = new Film();
          film.setName("我和我的父辈");
          film.setCategory(Arrays.asList("剧情"));
          mongoTemplate.insert(film);
      }
  
      @Test
      void testQuery() {
          List filmList = mongoTemplate.findAll(Film.class);
          System.out.println(filmList);
  
          Query query = new Query();
          query.addCriteria(Criteria.where("name").is("我和我的父辈").and("category").in("爱情","战争","剧情"));
          Film film = mongoTemplate.findOne(query, Film.class);
          System.out.println(film);
      }
  
      @Test
      void testSave() {
          Film film = new Film();
          film.setId("asdfgh");
          film.setName("长津湖");
          film.setCategory(Arrays.asList("战争","历史"));
          mongoTemplate.save(film);
      }
  
  }
  

  方式二：Spring Data MongoDB Repositories 

  定义一个Repository

  package com.cjs.example.repository;
  
  import com.cjs.example.domain.Film;
  import org.springframework.data.repository.CrudRepository;
  
  import java.util.List;
  
  
  public interface FilmRepository extends CrudRepository {
      
      List findByName(String name);
  }

  完整测试代码如下：

  package com.cjs.example;
  
  import com.cjs.example.domain.Film;
  import com.cjs.example.repository.FilmRepository;
  import org.junit.jupiter.api.Test;
  import org.springframework.boot.test.context.SpringBootTest;
  import org.springframework.data.mongodb.core.MongoTemplate;
  import org.springframework.data.mongodb.core.query.Criteria;
  import org.springframework.data.mongodb.core.query.Query;
  
  import javax.annotation.Resource;
  import java.util.Arrays;
  import java.util.List;
  
  @SpringBootTest
  class DemoMongodbApplicationTests {
  
      @Resource
      private MongoTemplate mongoTemplate;
  
      @Resource
      private FilmRepository filmRepository;
  
      
      @Test
      void contextLoads() {
          Film film = new Film();
          film.setName("我和我的父辈");
          film.setCategory(Arrays.asList("剧情"));
          mongoTemplate.insert(film);
      }
  
      @Test
      void testQuery() {
          List filmList = mongoTemplate.findAll(Film.class);
          System.out.println(filmList);
  
          Query query = new Query();
          query.addCriteria(Criteria.where("name").is("我和我的父辈").and("category").in("爱情","战争","剧情"));
          Film film = mongoTemplate.findOne(query, Film.class);
          System.out.println(film);
      }
  
      @Test
      void testSave() {
          Film film = new Film();
          film.setId("asdfgh");
          film.setName("长津湖");
          film.setCategory(Arrays.asList("战争","历史"));
          mongoTemplate.save(film);
      }
  
      @Test
      void testSaveByRepository() {
          filmRepository.save(new Film("1234", "火影忍者", Arrays.asList("动画","喜剧","动作","冒险")));
      }
  
      @Test
      void testQueryByRepository() {
          Film film = filmRepository.findById("1234").orElse(null);
          System.out.println(film);
          film = filmRepository.findByName("火影忍者").get(0);
          System.out.println(film);
  
          filmRepository.findAll().forEach(System.out::println);
      }
  }
  

  工程结构如下：