The best practice of optimizing the performance of Java library performance
The best practice of optimizing the performance of Java library performance
Summary:
Jpattern ORM is an object relationship mapping (ORM) framework for the Java class library. It provides a simple and powerful way to manage the mapping relationship between Java objects and databases.This article will introduce the best practice of some JPattern ORM to help developers use the framework to maximize the code performance.
1. Reasonably select the mapping relationship between the physical class and the database table
When using JPattern ORM, the mapping relationship between the physical class and the database table should be reasonably designed.This includes one -to -one physical class with its corresponding database table, and the field mapping relationship between the physical class and the database table correctly.A reasonable mapping relationship can ensure the consistency and integrity of the data, and improve the performance of the query operation.
Example code:
@Entity
@Table(name = "users")
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@Column(name = "username")
private String username;
@Column(name = "email")
private String email;
// Getters and setters
// ...
}
2. Use the cache to improve the query performance
The Jpattern ORM framework provides a cache mechanism to cache the query results into the memory to reduce the number of database access.Developers can improve the query performance by configured the appropriate cache strategy.The cache is suitable for those scenes that frequently queries but rarely changes data.
Example code:
JpatternSession session = JpatternSessionFactory.getSessionFactory().openSession();
Query query = session.createQuery("SELECT u FROM User u WHERE u.username = :username");
query.setParameter("username", "john");
query.setCacheable(true);
List<User> users = query.list();
3. Use batch operations to reduce the number of database access times
When using JPattern ORM to perform a large amount of database insertion, update, or delete operation, in order to improve performance, batch operations can be used.Batch operations allow multiple SQL statements through a database connection to reduce the overhead of database access.
Example code:
JpatternSession session = JpatternSessionFactory.getSessionFactory().openSession();
Transaction transaction = session.beginTransaction();
for (int i = 0; i < 1000; i++) {
User user = new User();
user.setUsername("user" + i);
user.setEmail("user" + i + "@example.com");
session.save(user);
if (i % 50 == 0) {
session.flush();
session.clear();
}
}
transaction.commit();
4. Avoid the performance loss caused by delay loading
The JPattern ORM framework supports the Lazy loading mechanism, that is, the data is loaded from the database only when accessing the relevant attributes.However, if the abuse is loaded, it may lead to additional database query and performance problems.Developers should be delayed and loaded reasonably according to actual needs to avoid unnecessary performance losses.
Example code:
@Entity
@Table(name = "users")
public class User {
// ...
@OneToMany(mappedBy = "user", fetch = FetchType.LAZY)
private List<Order> orders;
// ...
}
// Lazy load order list
User user = session.get(User.class, 1L);
List<Order> orders = user.getOrders();
in conclusion:
By following the best practice of the above JPattern ORM, developers can optimize the performance of the Java library.Reasonable selection of technical means such as the mapping relationship between the physical class and the database table, the use of cache, the execution of batch operations, and the reasonable configuration delay loading can maximize the code performance.These best practices are not only applicable to the JPattern ORM framework, but also the development and optimization process of other ORM frameworks.
references:
-Cattern ORM official document: [https://jpattern.net] (https://jpattern.net)
-Hibernate official document: [https://hibernate.org/]
