The use scene and precautions of the API in the API in the Java Library
The use scene and precautions of the API in the API in the Java Library
Java is a powerful programming language that provides rich libraries and tools to help developers simplify and manage code.The API is an important part of the Java library. It provides a mechanism to deal with database transactions to ensure the consistency and integrity of data.In this article, we will explore the use scenario of the API and the matters that need to be paid attention to.
scenes to be used:
1. Paid the database: When multiple threads access the database at the same time, we want to ensure the consistency and integrity of the data.The API provides a concurrent control mechanism, which can ensure that the database operation occurs at the same time as expected to avoid data conflict and inconsistency.
2. Atomicity of multiple database operations: If multiple database operations involve multiple database operations in one business logic, we hope that they are all successful or all fails.The transaction API allows us to encapsulate these operations in one transaction. If any of the operations fails, the entire transaction will be rolled back to maintain the consistency and integrity of the data.
3. Abnormal treatment: In database operations, various abnormalities may occur, such as connecting disconnection, timeout, deadlock, etc.The API provides an abnormal processing mechanism that can roll back when abnormalities appear to avoid the inconsistency and damage of data.
Precautions:
1. Open and submit transactions: Before the database operation, you need to open a transaction and submit it after the operation is completed.If the transaction API is not used, each database operation will be regarded as a separate transaction and cannot ensure the consistency of the data.
// Example of using transaction API to open and submit transaction
Connection connection = null;
try {
connection = dataSource.getConnection();
Connection.setAutocommit (false); // Open transaction
// Database operation
// ...
connection.commit (); // Submit transaction
} catch (SQLException e) {
connection.rollback (); // Roll back transactions
e.printStackTrace();
} finally {
Connection.setAutocommit (true); // Restore the default automatic submission mode
connection.close();
}
2. Paimorizing control: Affairs API provides lock mechanisms to achieve concurrent control, but pay attention to avoid the occurrence of dead locks.When performing database operations, you should minimize the particle size of the lock as much as possible to prevent other threads unable to access the database.
// Examples to implement complicated control with transaction API
try {
connection = dataSource.getConnection();
connection.setAutoCommit(false);
// Get the lock
statement.executeUpdate("SELECT * FROM table FOR UPDATE");
// Database operation
// ...
connection.commit();
} catch (SQLException e) {
connection.rollback();
e.printStackTrace();
} finally {
connection.setAutoCommit(true);
connection.close();
}
3. Performance and rollback: The use of transaction API will bring a certain amount of performance overhead, because each database operation needs to be opened and submitted.In the case of high application performance requirements, the scope and quantity of transactions should be appropriately controlled to reduce expenses.In addition, rolling operations will also affect performance, so it should be avoided rolling frequently.
in conclusion:
The API is a very important and useful part of the Java class library, which can help us realize the concurrent control, atomic and abnormal treatment of database operations.Using transaction API can ensure the consistency and integrity of the data and improve the stability of the application.However, it is necessary to pay attention to problems such as opening and submission, concurrency control, and rollback of transactions to ensure the correct use and efficient implementation of the affairs.
