SpringBoot整合MongoDB实现增删改查、复合查询

绝地灬酷狼 2022-01-14 12:55 345阅读 0赞

**1、向pom.xml中添加依赖包**

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

**2、编辑application.yml**

spring:
      data:
        mongodb:
          host: 192.168.58.129			//IP地址
          database: studentdb			//数据库名

**3、编写实体类**

解释一下以下用到的的几个注解：  
`@Id` ：文档的唯一标识，在mongodb中为ObjectId，它是唯一的，通过时间戳+机器标识+进程ID+自增计数器（确保同一秒内产生的Id不会冲突）构成。  
`@Document` ：把一个java类声明为mongodb的文档，可以通过collection参数指定这个类对应的文档。@Document(collection=”mongodb”) mongodb对应表

/** * 学生类 */
    @Document(collection = "student")    //指定对应的表名
    public class Student implements Serializable { 
        @Id
        private Integer id;
    
        private String name;
    
        private Integer age;
    
        private Integer gradeId;
    
        private Grade grade;
    
        public Grade getGrade() { 
            return grade;
        }
    
        public void setGrade(Grade grade) { 
            this.grade = grade;
        }
    
        public Integer getId() { 
            return id;
        }
    
        public void setId(Integer id) { 
            this.id = id;
        }
    
        public String getName() { 
            return name;
        }
    
        public void setName(String name) { 
            this.name = name;
        }
    
        public Integer getAge() { 
            return age;
        }
    
        public void setAge(Integer age) { 
            this.age = age;
        }
    
        public Integer getGradeId() { 
            return gradeId;
        }
    
        public void setGradeId(Integer gradeId) { 
            this.gradeId = gradeId;
        }
    
        @Override
        public String toString() { 
            return getId()+getName()+getAge()+getGradeId();
        }
    }

/** * 年级类 */
    public class Grade implements Serializable { 
    
        private Integer id;
    
        private String gradeName;
    
        public Integer getId() { 
            return id;
        }
    
        public void setId(Integer id) { 
            this.id = id;
        }
    
        public String getGradeName() { 
            return gradeName;
        }
    
        public void setGradeName(String gradeName) { 
            this.gradeName = gradeName;
        }
    }

**4、StudentDao接口**  
提供增删改查 MongoDB 接口

public interface StudentDao { 
        //查询所有
        List<Student> findAll();
    
        //增加
        void add(Student student);
    
        //删除
        void delete(Integer id);
    
        //修改
        void update(Student student);
        
        //符合查询——两表联查
        List<Map> fuhefind();
    }

**5、StudentDaoImpl实现类**

@Component
    public class StudentDaoImpl implements StudentDao { 
    
        @Autowired
        private MongoTemplate mongoTemplate;
    
        @Override
        public List<Student> findAll() { 
            return mongoTemplate.findAll(Student.class);
        }
    
        @Override
        public void add(Student student) { 
            mongoTemplate.save(student);
        }
    
        @Override
        public void delete(Integer id) { 
            Student student=mongoTemplate.findById(1,Student.class);
            mongoTemplate.remove(student);
        }
    
        @Override
        public void update(Student student) { 
            //修改的条件
            Query query = new Query(Criteria.where("id").is(student.getId()));
            //修改的内容
            Update update = new Update();
            update.set("name",student.getName());
    
            mongoTemplate.updateFirst(query,update,Student.class);
        }
    
        @Override
        public List<Map> fuhefind() { 
            LookupOperation lookupOperation=LookupOperation.newLookup().from("grade").localField("_id").foreignField("_id").as("grade");
            Aggregation aggregation=Aggregation.newAggregation(lookupOperation);
            List<Map> result=mongoTemplate.aggregate(aggregation,"student",Map.class).getMappedResults();
            return result;
        }
    }

**6、单元测试**

@RunWith(SpringRunner.class)
    @SpringBootTest
    public class SpringbootMongdbApplicationTests { 
    
        @Autowired
        private StudentDao studentDao;
    
        @Test
        public void findAll() { 
            List<Student> students=studentDao.findAll();
            System.out.println("查询到的数据的条数："+students.size());
            for (Student st:students
                 ) { 
                System.out.println(st.toString());
            }
        }
    
        @Test
        public void add(){ 
            Student student=new Student();
            student.setId(4);
            student.setName("李名明");
            student.setAge(19);
            student.setGradeId(3);
            studentDao.add(student);
            findAll();
        }
    
        @Test
        public void delete(){ 
            studentDao.delete(4);
            findAll();
        }
    
        @Test
        public  void update(){ 
            Student student=new Student();
            student.setId(2);
            student.setName("王麻子");
            student.setAge(15);
            student.setGradeId(1);
            studentDao.update(student);
            findAll();
        }
    
        @Test
        public void fehefind(){ 
            List<Map> maps = studentDao.fuhefind();
            for (Map map:maps
                 ) { 
                System.out.println(map);
            }
        }
    }

然后就自己去琢磨吧！  
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