Spring Batch - Spring Enterprise Recipes: A Problem Solution Approach - page 370

Next, the RPC layer below the system may also fault. Here's the rewritten code, this time allowing
for retries:
import java.util.List;
import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.log4j.Logger;
import org.springframework.batch.item.ItemWriter;
import org.springframework.batch.retry.RetryCallback;
import org.springframework.batch.retry.RetryContext;
import org.springframework.batch.retry.support.RetryTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import com.apress.springenterpriserecipes.springbatch.User;
import com.apress.springenterpriserecipes.springbatch.UserRegistrationService;
import com.apress.springenterpriserecipes.springbatch.solution1.UserRegistration;
/**
*
*
* This class writes the user registration by calling an RPC service (whose
* client interface is wired in using Spring
*/
public class RetryableUserRegistrationServiceItemWriter implements
ItemWriter<UserRegistration> {
private static final Logger logger = Logger
.getLogger(RetryableUserRegistrationServiceItemWriter.class);
// this is the client interface to an HTTP Invoker service.
@Autowired
private UserRegistrationService userRegistrationService;
@Autowired
private RetryTemplate retryTemplate;
/**
* takes aggregated input from the reader and 'writes' them using a custom
* implementation.
*/
public void write(List<? extends UserRegistration> items)
throws Exception {
for (final UserRegistration userRegistration : items) {
User registeredUser = retryTemplate.execute(
new RetryCallback<User>() {
public User doWithRetry(RetryContext context) throws Exception {
return userRegistrationService.registerUser(userRegistration);
}
});
logger.debug("Registered:"
+ ToStringBuilder.reflectionToString(registeredUser));
}
}
}