No EntityManager with actual transaction available for current thread - cannot reliably process 'remove' call, Exception - jpa

Question

Have a list of data need to be saved. Before the save had to delete the existing data and save the new data.
If any of the delete & save is failed that transaction need to roll back, rest of the delete & save transaction should continue.
public LabResResponse saveLabResult(List<LabResInvstResultDto> invstResults) {
LabResResponse labResResponse = new LabResResponse();
List<Long> relInvstid = new ArrayList<Long>();
try{
if(invstResults != null){
List<LabResInvstResult> labResInvstResults = mapper.mapAsList(invstResults, LabResInvstResult.class);
for(LabResInvstResult dto: labResInvstResults){
if(dto != null){
//delete all child records before save.
deleteResult(dto, relInvstid);
}
}
}
labResResponse.setRelInvstids(relInvstid);
}catch(Exception e){
e.printStackTrace();
}
return labResResponse;
}
Here new transaction will added for each delete & save
#Transactional(propagation = Propagation.REQUIRES_NEW, rollbackFor = { Exception.class })
private void deleteResult(LabResInvstResult dto, List<Long> relInvstid) {
try{
labResultRepo.deleteById(dto.getId());
LabResInvstResult result = labResultRepo.save(dto);
}catch(Exception e){
e.printStackTrace();
}
}
On delete it throws an exception "Caused by: javax.persistence.TransactionRequiredException: No EntityManager with actual transaction available for current thread - cannot reliably process 'remove' call"
I can solve this by adding a #Transactional for public LabResResponse saveLabResult(List invstResults) method.
But my intial usecase will not work this will roll back entire list of transaction.

Answer 1

Here are two problems.
The first problem is that you call the "real" deleteResult method of the class. When Spring sees #Transactional it creates a proxy object with transactional behavior. Unless you're using AspectJ it won't change the class itself but create a new one, proxy. So when you autowire this bean you will be able use proxy's method that runs transaction related logic. But in your case you're referencing to the method of the class, not proxy.
The second problem is that Spring (again if AspectJ is not used) can't proxy non-public methods.
Summary: make the deleteResult method public somehow and use proxied one. As a suggestion, use another component with deleteResult there.

Answer 2

You are catching exception out of for loop, while your requirement says you want to continue the loop for other objects in list.
Put your try/catch block with-in loop. It should work fine
public LabResResponse saveLabResult(List<LabResInvstResultDto> invstResults) {
LabResResponse labResResponse = new LabResResponse();
List<Long> relInvstid = new ArrayList<Long>();
try{
if(invstResults != null){
List<LabResInvstResult> labResInvstResults = mapper.mapAsList(invstResults, LabResInvstResult.class);
for(LabResInvstResult dto: labResInvstResults){
if(dto != null){
//delete all child records before save.
try {
deleteResult(dto, relInvstid);
} catch(Exception e){
e.printStackTrace();
}
}
}
}
labResResponse.setRelInvstids(relInvstid);
}catch(Exception e){
e.printStackTrace();
}
return labResResponse;
}