How to rollback with 2 transaction in same method on Spring Boot - java

#Service
#Transactional
public class UserServiceImpl implements UserService {
#Autowired
private UserRepository userRepository;
#Autowired
private RoleRepository roleRepository;
#Transactional
public void save(String name) {
method1(name);
method2(name);
}
public void method1(String name){
userRepository.save(name)
}
public void method2(String name) {
roleRepository.save(name);// Error
}
}
public interface UserService {
void save(String name) throws Exception;
}
#PostMapping("/save")
public void save() throws Exception {
userService.save("SomeThing");
}
I have 2 methods in the save method. As you can see, the method2 has an error.
I run the program, the first method prints to the database. However, if the second method is incorrect, I want the rollback process to fall and the first method not to be written to the database. How can I do it?
I tried to use #Transaction annotation on method1 and method2 but it error continued. And i tried Propagation.REQUIRES_NEW, and Propagation.REQUIRED, TransactionAspectSupport.currentTransactionStatus().setRollbackOnly(); never changed.

This is totally logical what you are trying to do. Just rollingback when one part of your flow fails is normal.
I'll give more background to make sure you have everything:
#Transactional only rollback, by default, when a RuntimeException is thrown. You can customize this. Check the doc, it is very easy to find out. Be careful, make sure you use org.springframework.transaction.annotation.Transactional. You have more options with this one.
Understanding propagation is key. By default, the propagation of #Transactional is Required, which means it will either joins an existing transaction, or creates a new one. Requires_New always create a new one. In your case, Propagation.REQUIRED is the good one.
Once you are in a Transactional method, adding #Transactional on other method inside your class and make inner call won't have any effect. The transaction starts when you enter in your method from the outside of your class. Once you in your class, the others annotations won't affect the runtime.
Three things/questions to consider:
What kind of error is throwing the RoleRepository.save(...) ?
What is the context ? Is it a test ? Is it a running application ? Could you provide more code ?
As said in one comment, read this: Spring Transaction Management with Hibernate and MySQL, Global and Local. You could have some issues with that as well...

Related

Why transactional does not rollback when RuntimeException occur?

I want to test a non-transactional method in the service layer when inner methods are transactional separately. I want to know what will happen if some method throws an exception. Does it properly roll back or not? I also tried rollbackFor but it did not help. Any suggestions?
Spring v-2.5.1
app.properties
spring.datasource.url=jdbc:mysql://localhost:3306/test
spring.datasource.username=root
spring.datasource.password=root
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.hibernate.ddl-auto=create-drop
server.error.include-message=always
server.error.include-binding-errors=always
Controller
#PostMapping("/test")
public void test(){
service.test();
}
Service
#Service
public class UserService {
#Autowired
private UserRepository userRepository;
#Autowired
private PasswordEncoder passwordEncoder;
public void test() {
User user1 = new User();
String encodedPassword = passwordEncoder.encode("123");
user1.setUsername("username");
user1.setPassword(encodedPassword);
user1.setFirst_name("name1");
user1.setLast_name("family1");
save(user1);
User update = update(user1.getUsername());
throw new RuntimeException();// I expect Spring rollback all data for save and update methods
//but it seems data has been committed before an exception occur.
}
#Transactional
public void save(User user) {
if (userExists(user.getUsername()))
throw new ApiRequestException("Username has already taken!");
else {
User user1 = new User();
String encodedPassword = passwordEncoder.encode(user.getPassword());
user1.setUsername(user.getUsername());
user1.setPassword(encodedPassword);
user1.setFirst_name(user.getFirst_name());
user1.setLast_name(user.getLast_name());
user1.setCreate_date(user.getCreate_date());
user1.setModified_date(user.getModified_date());
user1.setCompany(user.getCompany());
user1.setAddresses(user.getAddresses());
userRepository.save(user1);
// throw new RuntimeException(); Similarly I expect rollback here.
}
}
#Transactional
public User update(String username) {
User userFromDb = userRepository.findByUsername(username);
userFromDb.setFirst_name("new username");
userFromDb.setLast_name("new lastname");
return userRepository.save(userFromDb);
}
}
Due to way spring proxying works by default, you can not call a "proxied" method from within the instance.
Consider that when you put #Transactional annotation on a method, Spring makes a proxy of that class and the proxy is where the transaction begin/commit/rollback gets handled. The proxy calls the actual class instance. Spring hides this from you.
But given that, if you have a method on the class instance (test()), that calls another method on itself (this.save()), that call doesn't goes through the proxy, and so there is no "#Transactional" proxy. There is nothing to do the rollback when the RuntimeException occurs.
There are ways to change the how Spring does the proxying which would allow this to work, but it has changed over the years. There are various alternatives. One way is to create create separate classes. Perhaps UserServiceHelper. The UserServiceHelper contains #Transactional methods that get called by UserService. This same issue occurs when different #Transactional isolations and propagations are needed.
Related answers and info:
Spring #Transaction method call by the method within the same class, does not work?
Does Spring #Transactional attribute work on a private method?
Spring Transaction Doesn't Rollback
Your example code is not very clear as to what you are trying to do. Often, #Transactional would be put on the service class and apply to all public methods (like test()).
To begin with, I'm not sure if you understand what a transaction represents. If there's a unit of work that contains several functionalities to be executed, and you either want them to completely fail or completely pass - that's when you use a transaction.
So in the case of test() method - why should underlying mechanism (in this case Hibernate) care about rolling back something that happened within save() and update() when the test() itself isn't a transaction?
Sorry for asking more than answering, but as far as I can see - you need to annotate test() with the annotation, and not the individual methods. Or you can annotate them all.

Spring UnexpectedRollbackException in nested #Transactional method

I have a dao class (MyDao) which is marked with #Transactional annotaion (on class level) with no additional parameters. In this dao class I have a method which in some case needs to throw a checked exception and perform a transaction rollback. Something like this:
#Transactional
public class MyDao {
public void daoMethod() throws MyCheckedException() {
if (somethingWrong) {
TransactionAspectSupport.currentTransactionStatus().setRollbackOnly();
throw new MyCheckedException("something wrong");
}
}
This works perfectly fine. However, this dao method is called from a service method, which is also marked as #Transactional:
public class MyService {
#Autowired
private MyDao myDao;
#Transactional
public void serviceMethod() throws MyCheckedException {
myDao.daoMethod();
}
}
The problem is that when daoMethod() is called from serviceMethod() and marks the transaction as rollback only, I get an UnexpectedRollbackException.
Under the hood, Spring creates two transactional interceptors: one for MyDao and one for MyService. When daoMethod() marks the transaction for rollback, the interceptor for MyDao performs the rollback and returns. But then the stack moves to the interceptor for MyService, which finds out about the previous rollback, and throws the UnexpectedRollbackException.
One solution would be to remove the #Transactional annotation from MyDao. But this is not feasible right now because MyDao is used at a lot of places and this could cause errors.
Another solution would be to not set the transaction as rollback only in daoMethod() but rather mark serviceMethod() to revert the transaction on MyCheckedException. But I don't like this solution because I have a lot of these "service methods" and I would have to mark all of them explicitly to rollback on that exception. Also everyone who would add a new service method in the future would have to think of this and therefore it creates opportunities for errors.
Is there a way I could keep setting the transaction as rollback only from daoMethod() and prevent Spring from throwing the UnexpectedRollbackException? For instance, with some combination of parameters isolation and propagation?
I figured it out. I have to explicitly tell also the "outer" interceptor, that I want to rollback the transaction. In other words, both interceptors need to be "informed" about the rollback. This means either catching MyCheckedException in serviceMethod() and setting the transaction status to rollback only, or to mark serviceMethod() like this #Transactional(rollbackFor=MyCheckedException.class).
But as I mentioned in the OP, I want to avoid this because it's prone to errors. Another way is to make #Transactional rollback on MyCheckedException by default. But that's a completely different story.
Throwing an exception inside the transaction already trigger a rollback, using setRollbackOnly() is redundant here and that's probably why you have that error.
If the Transactionnal on the DAO is set up with Propagation.REQUIRED which is the default, then it will reuse an existing transaction if there is already one or create one if there is none. Here it should reuse the transaction created at the service layer.

AbstractRoutingDataSource doesn't change connection

I use AbstractRoutingDataSource to change data source dynamically and ThreadLocal to set up currentLookupKey. It works nice when I use only one data source per http request. I use JpaRepository
#Component
#Primary
public class RoutingDataSource extends AbstractRoutingDataSource {
#Autowired
private DatabaseMap databaseMap;
#Override
public void afterPropertiesSet() {
setTargetDataSources(databaseMap.getSourcesMap());
setDefaultTargetDataSource(databaseMap.getSourcesMap().get("DEFAULT"));
super.afterPropertiesSet();
}
#Override
protected Object determineCurrentLookupKey() {
return DatabaseContextHolder.getDatabaseType();
}
}
public class DatabaseContextHolder {
private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();
public static void setDatabaseType(String string) {
contextHolder.set(string);
}
public static String getDatabaseType() {
return (String) contextHolder.get();
}
public static void clearDatabaseType() {
contextHolder.remove();
}
}
When I try to get data in my REST controller I get data only from one database.
Some code in my REST controller
DatabaseContextHolder.setDatabaseType("db1");
//here I get data from db1 as expected
//I use JpaRepository
DatabaseContextHolder.clearDatabaseType();
DatabaseContextHolder.setDatabaseType("db2");
//here I should get data from db2 but get from db1
I tried to debug and it looks like Spring obtains data source only once in http request.
This method is called only once.
#Override
public Connection getConnection() throws SQLException {
return determineTargetDataSource().getConnection();
}
Is there any way to force Spring to change data source.
Your problem could be related with transaction delimitation.
When you define a #Transactional annotation in your code, Spring will create on your behalf all the stuff necessary to begin and end, and commiting or rollback if required, a transaction.
As you can see in the doBegin method in the source code of the DataSourceTransactionManager class - the same applies to other transaction managers - , Spring obtains a Connection when the transaction is initialized - this is why the method getConnection is invoked only once - , and it will reuse that connection across all the underlying operations against the database within that transaction (it makes sense for ACID preservation).
So, if you need to connect to several data sources within the same request processing, you can define different methods in you service code, every one annotated with a #Transactional annotation, and change the underlying data source as you require before invoke them:
DatabaseContextHolder.setDatabaseType("db1");
// Invoke a service method annotated with #Transactional
// It can use the underlying JpaRepositories that you need
DatabaseContextHolder.clearDatabaseType();
DatabaseContextHolder.setDatabaseType("db2");
// Invoke again another (or the same, what you need) service method
// annotated with #Transactional, You should get data from db2 this time
My suspicion here is you have a method annotated with #Transactional annotation. Before calling that transactional method, you first specify one datasource key and you call the transactional method.Inside the transactional method, you first call repository and it works as expected with datasource look up key you set. However then you set different key, inside the transactional method, and call another repository and it still uses the key you set first time.
DataSource will be chosen by the framework when the transaction starts so if you are using #Transactional annotation, whatever switching you do inside the method is useless. Because the datasource would have been chosen by proxy created for #Transactional annotation. Best option is to have the branching logic in non transactional service or use TransactionTemplate instead of #Transactional
For example, make sure YourRestController does not have class level #Transactional as well as no #Transactional annotation in this yourRestControllerMethod, you will keep them to your service.
#RestController
public class YourRestController {
#Autowired
TransactionalService transactional
public void yourRestControllerMethod(){
//set the datasource look up key to A1 and then
transactional.methodA1();
//change datasource look up key to A2 and then
transactional.methodA2();
}
}
#Service
public class TransactionalService {
#Transactional
public void methodA1(){
}
#Transactional
public void methodA2() {
}
}
I had the same issue, none of the above solution could fix it.. but making my Service method final (in my REST Controller)
public final Response
Set spring.jpa.open-in-view to false.

Spring transaction propagation - Service vs DAO

I have a Service class like below:
#Service("MyService")
public class MyService {
#Autowired
MyDao dao;
public void process() {
getFromDao();
// getMoreFromDao();
// process();
// if all good, then
doStuff();
}
public void getFromDao() {
// do some stuff
dao.getData();
}
#Transactional(transactionManager="simpleDatasourceTxMgr", propagation=Propagation.REQUIRED)
public void doStuff() {
dao.saveData(1);
dao.saveData(2);
dao.saveData(3);
}
}
The DAO called is:
#Repository
public class MyDao {
#Autowired
#Qualifier("myjdbcTemplate")
NamedParameterJdbcTemplate jdbcTemplate;
public void saveData(obj a) {
jdbcTemplate.execute("Query", ...);
}
}
I want my doStuff() method in the service class to run within a transaction and rollback everything if there is an exception in the saveData() method. But this is not running in transaction.
If I add #Transaction to a DAO method looks like it runs in separate transaction. Is this correct?
Update: I have added a process() method to my Service and I call getFromDao() and doStuff() from process(). process() is called from the controller. So looks like if I make the service class #Transactional, then everything executes within a transaction. But I don't want getFromDao() to execute in transaction.
We use just JDBC and no Hibernate.
You can place the #Transactional annotation before an interface
definition, a method on an interface, a class definition, or a public
method on a class. However, the mere presence of the #Transactional
annotation is not enough to activate the transactional behavior. The
#Transactional annotation is simply metadata that can be consumed by
some runtime infrastructure that is #Transactional-aware and that can
use the metadata to configure the appropriate beans with transactional
behavior. In the preceding example, the
element switches on the transactional behavior.
Or if you want annotations you can enable it with
It is not sufficient to tell you simply to annotate your classes with
the #Transactional annotation, add #EnableTransactionManagement to
your configuration, and then expect you to understand how it all
works. This section explains the inner workings of the Spring
Framework’s declarative transaction infrastructure in the event of
transaction-related issues.
http://docs.spring.io/spring/docs/current/spring-framework-reference/html/transaction.html

Strange behaviour for chainned transactional annotation

I don't get how it works the transactional annotations of Spring. So I made the next test with no practical sense but I It shows my problem:
public class TransactionalTest {
public void noTransaction(){
required();
}
#Transactional(propagation = Propagation.SUPPORTS)
public void supports(){
required();
}
#Transactional(propagation = Propagation.REQUIRED)
public void transaction(){
required();
}
#Transactional(propagation = Propagation.REQUIRED)
public void required(){
mandatory();
}
#Transactional(isolation = Isolation.READ_UNCOMMITTED, propagation = Propagation.MANDATORY)
public void mandatory(){
doSomething();
}
private void doSomething(){
//I don't feel like to do something.
}
}
Methods noTransaction, supports and transaction call to the same method: required but only the last one (transaction) works properly. The two others give me back the message No existing transaction found for transaction marked with propagation 'mandatory'.
In the real case, I have some non transactional methods which calls to transactional methods annotated with REQUIRED (It works fine). but if a non transactional method calls to a transactional method (annotated with REQUIRED) which it calls to another transactional method annoted with MANDATORY, it fails.
Why this behaviour and how can avoid it? I annotated annotate all the method which calls to a transaccional method just in case?
If you're using the default AOP method, Spring Proxy AOP, the advice is implemented by wrapping the annotated class with a proxy object that intercepts and advises the calls. When you use self-calls like this, you're bypassing the proxy, and the advice doesn't get applied.
If you really do need to have advice applied on self-calls, you need to use AspectJ AOP, which actually modifies the class in question instead of decorating it.

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