In -depth understanding of the affairs management and Java affairs in the Java class library API
In -depth understanding of the affairs management and Java affairs in the Java class library API
Overview:
When developing enterprise -level applications, transaction management is a very important aspect.Affairs is a collection of a series of database operations. It is regarded as an inseparable unit, either successfully implemented or rolling back.Java provides many libraries and APIs for transaction management.This article will explore the use of transaction management mechanisms in the Java class library and the use of the Java affairs API.
1. Affairs management in the Java library:
In the Java library, transaction management mainly depends on the Java database connection (JDBC) and Java persistent API (JPA).
1. Java database connection (JDBC) transaction:
JDBC provides a basic mechanism for managing affairs.The following steps are required to use JDBC for transaction management:
a. Use DriverManager.getConnection () method to obtain database connections.
b. Close automatic submission mode: Connection.setAutocommit (false).
c. Create and execute SQL statements.
d. If the transaction is successfully completed, use connection.commit () to submit the transaction; otherwise, use connection.rollback () to roll back the transaction.
e. Finally, turn off the database connection with connection.close ().
The following is an example code, which demonstrates how to use JDBC for transaction management:
Connection connection = null;
try {
connection = DriverManager.getConnection(<database_url>, <username>, <password>);
Connection.setAutocommit (false); // Close automatic submission
// Execute the SQL statement
// ...
connection.commit (); // Submit transaction
} catch (SQLException e) {
if (connection != null) {
try {
connection.rollback (); // Roll back transactions
} catch (SQLException ex) {
// Treatment of rollback abnormalities
}
}
} finally {
if (connection != null) {
try {
connection.close (); // Close the connection
} catch (SQLException e) {
// Treatment Close connection abnormalities
}
}
}
2. Java persistent API (JPA) transaction:
The Java persistence API (JPA) is a high-level ORM (Object-Relational Mapping) technology, which provides database access and transaction management in a more simplified and transplant way.JPA provides a set of interfaces and annotations for the persistence of the physical class.
In JPA, transaction management is usually used with container (such as application server).The container is responsible for managing the life cycle of connection and transactions. Developers only need to use the JPA API for related operations.
The following is an example code, which demonstrates how to manage transaction in JPA:
EntityManagerFactory emf = Persistence.createEntityManagerFactory(<persistence_unit_name>);
EntityManager em = emf.createEntityManager();
EntityTransaction transaction = em.getTransaction();
try {
transaction.begin (); // Open transaction
// Execute the database operation
// ...
transaction.commit (); // Submit transactions
} catch (Exception e) {
if (transaction != null && transaction.isActive()) {
transaction.rollback (); // Roll back transactions
}
} finally {
if (em != null && em.isOpen()) {
em.Close (); // Close entityManager
}
}
2. Java Affairs API:
Java Affairs API (Javax.transaction) is a set of standard interfaces used to manage distributed transactions in the Java platform.The API provides a mechanism that allows applications to manage transactions across multiple resource managers (such as databases, message queues, etc.) in a consistent manner.The Java transaction API consists of two core interfaces: useRTRANSACTION and TransactionManager.
1. UserTransaction interface:
UseRTRACTION interface provides a set of methods for the isolation level of starting, submission, rollback and setting transactions.The following is some of the methods of using the UserTransaction interface:
-BEGIN (): Open transaction.
-Commit (): Submit a transaction.
-rollback (): Roll back transactions.
-SettransactionTimeout (int Timeout): Set timeout of transaction.
2. TransactionManager interface:
TransactionManager interface is the core interface of the transaction manager, which is responsible for controlling the entire transaction process.The following are some methods of the transactionManager interface:
-BEGIN (): Open transaction.
-Commit (): Submit a transaction.
-rollback (): Roll back transactions.
-SettransActionTimeout (INT Seconds): Set the timeout of transactions.
-gettransactions (): Get the current transaction.
-GettransActionStatus (): Get the status of the current transaction.
The use of the Java transaction API depends on specific applications and frameworks.Under normal circumstances, the transaction manager is provided by the application server or persistence framework. Developers manage transactions by calling the corresponding API method.
The above is the in -depth understanding of the transaction management in the Java library and the API of the Java affairs API.Affairs management plays an important role in enterprise -level applications to ensure data integrity and consistency.Through reasonable use of transaction management mechanisms and APIs, developers can better manage and control transaction operations in applications.
