Understanding Spring @Transactional Rollback Behavior and Exception Handling

First, a MySQL record is prepared for testing the update of the delflag field to 0:

UPDATE tbl_users set delflag='0' where account='admin'

A simple test method annotated with @Transactional performs a division by zero, which throws java.lang.ArithmeticException (a subclass of RuntimeException), causing the transaction to roll back:

@Override
@Transactional
public Ret test() {
    int i = articleMapper.test();
    int a = 2/0; // throws ArithmeticException
    if(i > 0){
        ResultUtil.success();
    }
    return ResultUtil.error();
}

Running this test shows that the database value is not changed because the transaction is rolled back when the RuntimeException occurs.

When the method catches the exception and rethrows a checked Exception, the transaction does not roll back, and the database update persists:

@Override
@Transactional
public Ret test() throws Exception {
    int i = articleMapper.test();
    try {
        int a = 2/0;
    } catch (Exception e) {
        throw new Exception();
    }
    if(i > 0){
        ResultUtil.success();
    }
    return ResultUtil.error();
}

This demonstrates that @Transactional rolls back only for RuntimeException (and its subclasses). To roll back for checked exceptions like Exception, specify the rollbackFor attribute: @Transactional(rollbackFor = Exception.class) Therefore, when you need transaction rollback for any exception type, use @Transactional(rollbackFor = Exception.class) in your service methods.