Introduction to the technical principles of the "Affairs API" framework in the Java library

The API framework in the Java library is a key tool for managing database transactions.Affairs refers to the process of execution as a set of operations as a single logic unit.They are either successfully executed or rolled back to maintain the consistency of data.By using the API framework, you can ensure that the database is rolled correctly when errors or abnormalities occur, and data completeness can be maintained. The technical principle of the API framework involves the following key concepts and components: 1. Transaction Manager: The transaction manager is one of the core components of the API framework.It is responsible for the creation, submission and rollback of affairs.In Java, the transaction manager is usually created by the transaction manager factory and is implemented using a driver specific in the database. The following is an example of creating and submitting transactions using Java code: // Create a transaction manager TransactionManager transactionManager = TransactionManagerFactory.createTransactionManager(); try { // Open transaction transactionManager.beginTransaction(); // Execute the database operation // ... // Submit a transaction transactionManager.commitTransaction(); } catch (Exception e) { // Roll back transactions transactionManager.rollbackTransaction(); // Treatment abnormalities // ... } 2. Data Source: Data source is the interface between the API framework and the database.It provides the ability to obtain database connection and is responsible for coordinating and managing the life cycle of the management database connection.The data source in Java is usually driven by Java DataBase Connectivity (JDBC). The following is an example of using the JDBC data source to obtain database connection: // Create a data source DataSource dataSource = DataSourceFactory.createDataSource(); // Get the database connection Connection connection = dataSource.getConnection(); // Execute the database operation // ... // Close the database connection connection.close(); 3. Transaction Isolation Level: The degree of isolation between multiple concurrent transactions is defined.The API framework in Java usually provides multiple transaction isolation level options, such as unsurmitting, reading, repeated reading, and serialization. The following is an example of setting a transaction isolation level using Java code: // Set the transaction isolation level to be submitted for reading transactionManager.setTransactionIsolationLevel(TransactionIsolationLevel.READ_COMMITTED); 4. Savepoint: The rollback point is a mark in the transaction to restore the state from the state after the point to the previous state.It allows to set multiple preservation points during transaction execution and selectively roll back to the specified saving point when errors or abnormalities occur. The following is an example of using Java code settings and rolling back to roll points: // Set the rollback point Savepoint savepoint = transactionManager.setSavepoint("savepoint1"); try { // Execute the database operation // ... // Submit a transaction transactionManager.commitTransaction(); } catch (Exception e) { // Roll back to the save point transactionManager.rollbackToSavepoint(savepoint); // Treatment abnormalities // ... } In summary, the API framework is an important tool for managing database transactions in the Java class library.It ensures that the database is correctly rolled to the database by using the key concepts and components such as transaction manager, data source, transaction isolation level, and rolling points.