Spring MongoRepository example 2016-06-01 06:38
In this page I will show you how to use MongoRepository insert, delete, update and query document. I assume you have installed MongoDB in your computer. If you don't know how to work with MongoDB you can learn basic methods from MongoDB tutorial. MongoRepository is a interface which can help you CRUD document in MongoDB.
project structure
For quickly start I use Spring boot to run the demo.
└─main
├─java
│ └─mongo
│ └─keywords
│ └─repository
│ QueryClient.java
│ User.java
│ UserRepository.java
│
└─resources
application.properties
application.properties
spring.data.mongodb.host=localhost
spring.data.mongodb.port=27017
spring.data.mongodb.database=user_database
User
public class User {
@Id
private String id;
private String name;
private int age;
private Address address;
public User() {
}
public User(String name, int age) {
this.name = name;
this.age = age;
}
public User(String name, int age, Address address) {
this.name = name;
this.age = age;
this.address = address;
}
//getter and setter methods
@Override
public String toString() {
return "User{" +
"id='" + id + '\'' +
", name='" + name + '\'' +
", age=" + age +
'}';
}
}
address
public class Address {
private String country;
private String city;
//getter and setter method
}
UserRepository
interface UserRepository extends MongoRepository<User, String> {
List<User> findByAge(Long age);
}
QueryClient
@SpringBootApplication
public class QueryClient implements CommandLineRunner {
@Autowired
private UserRepository userRepository;
public static void main(String[] args) {
SpringApplication.run(QueryClient.class, args);
}
public void run(String... strings) throws Exception {
// save data
User henry = new User("Henry", 27);
userRepository.save(henry);
Address beijing = new Address("China", "Beijing");
Address shanghai = new Address("China", "Shanghai");
User justin = new User("Justin", 28, beijing);
User mathew = new User("Mathew", 23,shanghai);
List<User> users = new ArrayList<User>();
users.add(justin);
users.add(mathew);
userRepository.save(users);
//delete data
String justinId = justin.getId();
justin.setId("123456");
userRepository.delete(justin);//delete fail when change the id
userRepository.delete(justinId);
//query data
List<User> usersInDB = userRepository.findByAge(23L);
String id = usersInDB.get(0).getId();
User user = userRepository.findOne(id);
System.out.println(user);
//update data
User updateUser = userRepository.findOne(id);
updateUser.setName("new name");//update date need query it first
userRepository.save(updateUser);
User newUser = userRepository.findOne(id);
System.out.println(newUser);
}
}
You can save date(document) one by one(save(S entity) or save multiple in one time(save(Iterable<S> entites)). Don't change the id of entity when you delete document by delete(T entity). Delete by id always works if you make sure the id is correct. For updating document you need query it first then change the properties and save it again.