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[refactor] Remove unnecessary declarations in service-locator pattern.

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This commit is contained in:
ruslanpa 2015-02-10 10:02:44 +02:00
parent 4b432a79d9
commit 14058082bb
6 changed files with 119 additions and 120 deletions
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28
service-locator/src/main/java/com/iluwatar/App.java
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@ -1,20 +1,20 @@
package com.iluwatar;
/**
* Service locator pattern, used to lookup jndi services
* and cache them for subsequent requests.
* @author saifasif
* Service locator pattern, used to lookup jndi services
* and cache them for subsequent requests.
*
* @author saifasif
*/
public class App {
public static void main(String[] args) {
Service service = ServiceLocator.getService("jndi/serviceA");
service.execute();
service = ServiceLocator.getService("jndi/serviceB");
service.execute();
service = ServiceLocator.getService("jndi/serviceA");
service.execute();
service = ServiceLocator.getService("jndi/serviceA");
service.execute();
}
public static void main(String[] args) {
Service service = ServiceLocator.getService("jndi/serviceA");
service.execute();
service = ServiceLocator.getService("jndi/serviceB");
service.execute();
service = ServiceLocator.getService("jndi/serviceA");
service.execute();
service = ServiceLocator.getService("jndi/serviceA");
service.execute();
}
}

38
service-locator/src/main/java/com/iluwatar/InitContext.java
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@ -3,27 +3,27 @@ package com.iluwatar;
/**
* For JNDI lookup of services from the web.xml. Will match name of the service name that
* is being requested and return a newly created service object with the name
* @author saifasif
*
* @author saifasif
*/
public class InitContext {
/**
* Perform the lookup based on the service name. The returned object will need to be
* casted into a {@link Service}
* @param serviceName
* @return
*/
public Object lookup(String serviceName){
if( serviceName.equals("jndi/serviceA") ){
System.out.println("Looking up service A and creating new service for A");
return new ServiceImpl("jndi/serviceA");
} else if( serviceName.equals("jndi/serviceB") ){
System.out.println("Looking up service B and creating new service for B");
return new ServiceImpl("jndi/serviceB");
} else {
return null;
}
}
/**
* Perform the lookup based on the service name. The returned object will need to be
* casted into a {@link Service}
*
* @param serviceName a string
* @return an {@link Object}
*/
public Object lookup(String serviceName) {
if (serviceName.equals("jndi/serviceA")) {
System.out.println("Looking up service A and creating new service for A");
return new ServiceImpl("jndi/serviceA");
} else if (serviceName.equals("jndi/serviceB")) {
System.out.println("Looking up service B and creating new service for B");
return new ServiceImpl("jndi/serviceB");
} else {
return null;
}
}
}

7
service-locator/src/main/java/com/iluwatar/Service.java
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@ -14,16 +14,15 @@ public interface Service {
/*
* The human readable name of the service
*/
public String getName();
String getName();
/*
* Unique ID of the particular service
*/
public int getId();
int getId();
/*
* The workflow method that defines what this service does
*/
public void execute();
void execute();
}

63
service-locator/src/main/java/com/iluwatar/ServiceCache.java
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@ -5,42 +5,43 @@ import java.util.Map;
/**
* The service cache implementation which will cache services that are being created.
* On first hit, the cache will be empty and thus any service that is being requested, will be
* On first hit, the cache will be empty and thus any service that is being requested, will be
* created fresh and then placed into the cache map. On next hit, if same service name will
* be requested, it will be returned from the cache
* @author saifasif
* be requested, it will be returned from the cache
*
* @author saifasif
*/
public class ServiceCache {
private Map<String, Service> serviceCache;
public ServiceCache() {
serviceCache = new HashMap<String, Service>();
}
private final Map<String, Service> serviceCache;
/**
* Get the service from the cache. null if no service is found matching the
* name
* @param serviceName
* @return {@link Service}
*/
public Service getService(String serviceName){
Service cachedService = null;
for (String serviceJndiName : serviceCache.keySet()){
if( serviceJndiName.equals( serviceName ) ){
cachedService = serviceCache.get(serviceJndiName);
System.out.println("(cache call) Fetched service " + cachedService.getName() + "("+cachedService.getId()+") from cache... !");
}
}
return cachedService;
}
public ServiceCache() {
serviceCache = new HashMap<String, Service>();
}
/**
* Adds the service into the cache map
* @param newService
*/
public void addService(Service newService){
serviceCache.put(newService.getName(), newService);
}
/**
* Get the service from the cache. null if no service is found matching the name
*
* @param serviceName a string
* @return {@link Service}
*/
public Service getService(String serviceName) {
Service cachedService = null;
for (String serviceJndiName : serviceCache.keySet()) {
if (serviceJndiName.equals(serviceName)) {
cachedService = serviceCache.get(serviceJndiName);
System.out.println("(cache call) Fetched service " + cachedService.getName() + "(" + cachedService.getId() + ") from cache... !");
}
}
return cachedService;
}
/**
* Adds the service into the cache map
*
* @param newService a {@link Service}
*/
public void addService(Service newService) {
serviceCache.put(newService.getName(), newService);
}
}

52
service-locator/src/main/java/com/iluwatar/ServiceImpl.java
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@ -1,37 +1,37 @@
package com.iluwatar;
/**
* This is a single service implementation of a sample service. This is the actual
* service that will process the request. The reference for this service is to
* This is a single service implementation of a sample service. This is the actual
* service that will process the request. The reference for this service is to
* be looked upon in the JNDI server that can be set in the web.xml deployment descriptor
* @author saifasif
*
* @author saifasif
*/
public class ServiceImpl implements Service {
private String serviceName;
private int id;
public ServiceImpl(String serviceName) {
// set the service name
this.serviceName = serviceName;
// Generate a random id to this service object
this.id = (int)Math.floor(Math.random()*1000)+1;
}
@Override
public String getName() {
return serviceName;
}
private final String serviceName;
private final int id;
@Override
public int getId() {
return id;
}
public ServiceImpl(String serviceName) {
// set the service name
this.serviceName = serviceName;
@Override
public void execute() {
System.out.println("Service " + getName() + " is now executing with id " + getId());
}
// Generate a random id to this service object
this.id = (int) Math.floor(Math.random() * 1000) + 1;
}
@Override
public String getName() {
return serviceName;
}
@Override
public int getId() {
return id;
}
@Override
public void execute() {
System.out.println("Service " + getName() + " is now executing with id " + getId());
}
}

51
service-locator/src/main/java/com/iluwatar/ServiceLocator.java
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@ -3,35 +3,34 @@ package com.iluwatar;
/**
* The service locator module.
* Will fetch service from cache, otherwise creates a fresh service and update cache
*
* @author saifasif
*
* @author saifasif
*/
public class ServiceLocator {
private static ServiceCache serviceCache = new ServiceCache();
/**
* Fetch the service with the name param from the cache first,
* if no service is found, lookup the service from the {@link InitContext} and
* then add the newly created service into the cache map for future requests.
* @param serviceJndiName
* @return {@link Service}
*/
public static Service getService(String serviceJndiName){
Service serviceObj = serviceCache.getService(serviceJndiName);
if ( serviceObj != null ){
return serviceObj;
} else {
/*
* If we are unable to retrive anything from cache, then
private static ServiceCache serviceCache = new ServiceCache();
/**
* Fetch the service with the name param from the cache first,
* if no service is found, lookup the service from the {@link InitContext} and
* then add the newly created service into the cache map for future requests.
*
* @param serviceJndiName a string
* @return {@link Service}
*/
public static Service getService(String serviceJndiName) {
Service serviceObj = serviceCache.getService(serviceJndiName);
if (serviceObj != null) {
return serviceObj;
} else {
/*
* If we are unable to retrive anything from cache, then
* lookup the service and add it in the cache map
*/
InitContext ctx = new InitContext();
serviceObj = (Service) ctx.lookup(serviceJndiName);
serviceCache.addService(serviceObj);
return serviceObj;
}
}
InitContext ctx = new InitContext();
serviceObj = (Service) ctx.lookup(serviceJndiName);
serviceCache.addService(serviceObj);
return serviceObj;
}
}
}