Transaction Management - Spring boot - supper 4 link

 

one and only explanation go-through below 4 topic for mastering @Transaction  

Spring Boot Transaction Management - Table of Contents
Spring Boot Transaction Management Example
Spring Boot Transactions - Understanding Transaction Isolation  
Spring Boot Transactions - Understanding Transaction Propagation : for Unchecked Exceptions (Runtime Exceptions ) 
Spring Boot Transactions - Understanding Transaction Rollbacks :for checked Exceptions (Compile time exceptions)

                                                     Transaction propagation

                                                     Transaction Isolation

in Java and some other programming languages, exceptions are categorized into two main types: checked exceptions and unchecked exceptions.

===================================================================================Type of Exceptions ========================= ========================================================================================================================

1. Checked Exceptions:

   • Checked exceptions are exceptions that are checked at compile-time. This means that the compiler ensures that the code handling these exceptions includes proper exception handling mechanisms.
   • These exceptions are subclasses of the Exception class (excluding RuntimeException and its subclasses).
   • Examples of checked exceptions include IOException, SQLException, and ClassNotFoundException.
   • The handling of checked exceptions is mandatory, either by using a try-catch block or by declaring the method to throw the exception using the throws keyword.

   java
   try {
       // Code that may throw a checked exception
   } catch (IOException e) {
       // Handle the exception
   }
   

   java
   public void readFile() throws IOException {
       // Code that may throw a checked exception
   }
   

2. Unchecked Exceptions:

   • Unchecked exceptions, also known as runtime exceptions, are not checked at compile-time. They typically result from programming errors and are subclasses of RuntimeException.
   • Examples of unchecked exceptions include NullPointerException, ArrayIndexOutOfBoundsException, and ArithmeticException.
   • Handling unchecked exceptions is optional. If they occur, they can be caught using a try-catch block, but it's not required.

   java
   try {
       // Code that may throw an unchecked exception
   } catch (NullPointerException e) {
       // Handle the exception
   }
   

   java
   // Unchecked exceptions do not need to be declared in the method signature
   public void divide(int a, int b) {
       // Code that may throw an unchecked exception
   }
   

In summary, the key difference lies in whether the compiler enforces handling of exceptions. Checked exceptions must be either caught or declared in the method signature, whereas unchecked exceptions do not have this requirement. Unchecked exceptions are often used for programming errors that should be addressed during development, while checked exceptions are typically used for external factors that a program should be prepared to handle at runtime.

In Java, the @Transactional annotation is often used in the context of database transactions, typically in a Spring Framework application. It helps manage transactions, and its behavior is closely related to database operations.

============================================================================Type of Exceptions with transaction handling ============== ======================== ======= ============================ ============================================================

In Java, the @Transactional annotation is often used in the context of database transactions, typically in a Spring Framework application. It helps manage transactions, and its behavior is closely related to database operations.

The @Transactional annotation primarily deals with runtime exceptions (unchecked exceptions) to control the behavior of transactions. Here's how it generally works:

1. Unchecked Exceptions (RuntimeExceptions):

   • By default, if a runtime exception is thrown within a method annotated with @Transactional, the transaction will be marked for rollback. This means that any changes made within that transaction will be undone, and the transaction will not be committed.

   java
   @Transactional
   public void performDatabaseOperation() {
       // Database operations
   
       // This unchecked exception will trigger a rollback
       throw new RuntimeException("Simulating a runtime exception");
   }
   

2. Checked Exceptions:

   • Checked exceptions, which are not subclasses of RuntimeException, are not subject to automatic rollback by default. If you want a checked exception to trigger a rollback, you typically need to configure your transaction management accordingly, using the rollbackFor attribute of the @Transactional annotation.

   java
   @Transactional(rollbackFor = SomeCheckedException.class)
   public void performDatabaseOperation() throws SomeCheckedException {
       // Database operations
   
       // This checked exception will trigger a rollback
       throw new SomeCheckedException("Simulating a checked exception");
   }
   

   In the example above, the transaction will be rolled back if SomeCheckedException is thrown.

It's important to note that the behavior may vary depending on the specific transaction management configuration, the underlying database, and the Spring version being used. Always refer to the documentation for the version of Spring you are using for the most accurate and up-to-date information.

================================================================================================================================================================================================================================================

In Java, exceptions are categorized into runtime exceptions and compile-time exceptions. The terms transient and non-transient are not typically used to describe exceptions, but I'll cover them in the context of persistence for objects and how they relate to exceptions.

Compile-Time Exception

• Also known as checked exceptions.
• Must be either handled with a try-catch block or declared in the method signature using throws.
• Examples:
  • IOException
  • SQLException
  • ClassNotFoundException

Runtime Exception

• Also known as unchecked exceptions.
• Occurs during program execution and does not need to be declared or explicitly handled.
• Examples:
  • NullPointerException
  • ArrayIndexOutOfBoundsException
  • ArithmeticException

---

Transient and Non-Transient in Exceptions

The terms transient and non-transient exceptions are sometimes used in frameworks or custom exception handling to denote recoverability:

1. Transient Exceptions:

   • Exceptions that are temporary and can be retried.
   • Often caused by issues like network errors, database connection issues, or service unavailability.
   • Example: A custom DatabaseConnectionTimeoutException may be transient, as retrying might solve the issue.

2. Non-Transient Exceptions:

   • Exceptions that are permanent and indicate a fundamental problem.
   • Retrying is unlikely to resolve the issue.
   • Example: IllegalArgumentException, NullPointerException, or issues caused by incorrect input or configuration.

---

Transient exceptions can be either runtime or compile-time exceptions, depending on their implementation. The transient nature of an exception refers to its recoverability or temporary nature, not its category in terms of runtime or compile-time.

1. Runtime Exceptions (Unchecked Transient Exceptions):

• These are unchecked exceptions that occur at runtime.
• They do not need to be declared in the method signature or explicitly handled in a try-catch block.
• Example: A transient runtime exception might occur due to a temporary issue such as a network timeout.

throw new RuntimeException("Temporary network issue, please retry.");

2. Compile-Time Exceptions (Checked Transient Exceptions):

• These are checked exceptions that occur during compilation.
• They must be declared in the method signature using throws or handled with a try-catch block.
• Example: A transient checked exception might occur due to a temporary file access issue.

class TransientCheckedException extends Exception {
    public TransientCheckedException(String message) {
        super(message);
    }
}

public void accessFile() throws TransientCheckedException {
    throw new TransientCheckedException("Temporary file access issue, please retry.");
}

Summary:

• Transient exceptions can be both runtime or compile-time, depending on whether they extend RuntimeException (unchecked) or Exception (checked).
• The term "transient" describes the temporary or recoverable nature of the issue, not the exception type itself.

runtime or compile-time, decide  on how they extend RuntimeException (unchecked) or Exception (checked)

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