TransactionRequiredException: No EntityManager with actual transaction available for current thread - cannot reliably process 'merge' call - spring

Question

We have some old spring applications where we have little bit spring-boot annotations. I have a scenario where I want to perform merge using EntityManager, but this is throwing "javax.persistence.TransactionRequiredException: No EntityManager with actual transaction available for current thread - cannot reliably process 'merge' call" exception. I have tried solutions available in other post such as using javax.persistent #Trasactional annotations on the upload() method level, but nothing worked. These are the classes I am using -
ApplicationContextProvider.java
#Service
public class ApplicationContextProvider implements ApplicationContextAware {
private static ApplicationContext context;
public static ApplicationContext getApplicationContext() {
return context;
}
#Override
public void setApplicationContext(ApplicationContext ac) throws BeansException {
context = ac;
}
}
MyConfigType.java
#Entity
#Table(name = "config_loaded_table")
public class MyConfigType {
#Id
private int id;
#Column(name = "file_name")
private String fileName;
// getters and setters
}
ConfigUploader.java (abstract class)-
public abstract class ConfigUploader {
public abstract String upload() throws Exception;
}
ConfigLoader implementation class where I am using merge from entityManager-
public class MyConfigLoader extends ConfigUploader {
private int id;
private String path;
public MyConfigLoader(int id, String path) {
this.id= id;
this.path=path;
}
#Override
public String upload() throws Exception {
try {
MyConfigType myConfigType = new MyConfigType();
myConfigType.setFileName("employee.config");
// at this line I am getting exception.
int id = ApplicationContextProvider.getApplicationContext().getBean(EntityManager.class).merge(myConfigType).getId();
myConfigType.setId(id);
}catch (Exception e) {
// getting javax.persistence.TransactionRequiredException: No EntityManager with actual transaction available for current thread - cannot reliably process 'merge' call
log.error(e);
}
}
}
And finally, the main class where I am calling upload() method of ConfigLoader implementation-
public class ConfigThread implements Runnable {
#Override
public void run() {
ConfigUploader configLoader = new MyConfigLoader(id,path);
configLoader.upload(); // calling upload() method here
}
}

Answer 1

Unfortunetly, your class is not a spring component, so #Transactional can not be used here. You can try something like this:
EntityManager entityManager = ApplicationContextProvider.getApplicationContext().getBean(EntityManager.class);
entityManager.getTransaction().begin();
entityManager.merge(...);
entityManager.getTransaction().commit();