开发笔记:业务代表模式

interface BusinessService {
void doProcess();
}
class EJBService implements BusinessService {
public void doProcess() {
System.out.println("Process from EJBService");
}
}
class JMSService implements BusinessService {
public void doProcess() {
System.out.println("Process from JMSService");
}
}
class BusinessLockup {
public static BusinessService getService(String serviceType) {
if (serviceType.equalsIgnoreCase("EJB")) {
return new EJBService();
} else {
return new JMSService();
}
}
}
class BusinessDelegate {
private String serviceType;
private BusinessService businessService;
public void setServiceType(String serviceType) {
this.serviceType = serviceType;
}
public void process() {
businessService = BusinessLockup.getService(serviceType);
businessService.doProcess();
}
}
class Client {
private BusinessDelegate delegate;
public Client(BusinessDelegate delegate) {
this.delegate = delegate;
}
public void doTask() {
delegate.process();
}
}
public class DelegatePatternDemo {
public static void main(String args[]) {
BusinessDelegate delegate = new BusinessDelegate();
delegate.setServiceType("EJB");
Client client1 = new Client(delegate);
client1.doTask();
delegate.setServiceType("JMS");
Client client2 = new Client(delegate);
client2.doTask();
}
}