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Java 11 migration: patterns (remaining b-c) (#1081)

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* Moves business-delegate pattern  to java 11

* Moves bytecode pattern  to java 11

* Moves caching pattern  to java 11

* Moves callback pattern  to java 11

* Moves chain pattern  to java 11

* Moves circuit-breaker pattern  to java 11

* Moves collection-pipeline pattern  to java 11

* Moves command pattern  to java 11

* Moves commander pattern  to java 11

* Moves composite pattern  to java 11

* Corrects test cases
This commit is contained in:
Anurag Agarwal
2019-11-13 01:26:46 +05:30
committed by Ilkka Seppälä
parent 6ef840f3cf
commit 33ea7335b1
63 changed files with 798 additions and 979 deletions
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18
caching/src/main/java/com/iluwatar/caching/App.java
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@ -76,7 +76,7 @@ public class App {
// true to run the tests with MongoDB (provided that MongoDB is
// installed and socket connection is open).
AppManager.initCacheCapacity(3);
App app = new App();
var app = new App();
app.useReadAndWriteThroughStrategy();
app.useReadThroughAndWriteAroundStrategy();
app.useReadThroughAndWriteBehindStrategy();
@ -90,7 +90,7 @@ public class App {
LOGGER.info("# CachingPolicy.THROUGH");
AppManager.initCachingPolicy(CachingPolicy.THROUGH);
UserAccount userAccount1 = new UserAccount("001", "John", "He is a boy.");
var userAccount1 = new UserAccount("001", "John", "He is a boy.");
AppManager.save(userAccount1);
LOGGER.info(AppManager.printCacheContent());
@ -105,7 +105,7 @@ public class App {
LOGGER.info("# CachingPolicy.AROUND");
AppManager.initCachingPolicy(CachingPolicy.AROUND);
UserAccount userAccount2 = new UserAccount("002", "Jane", "She is a girl.");
var userAccount2 = new UserAccount("002", "Jane", "She is a girl.");
AppManager.save(userAccount2);
LOGGER.info(AppManager.printCacheContent());
@ -127,9 +127,9 @@ public class App {
LOGGER.info("# CachingPolicy.BEHIND");
AppManager.initCachingPolicy(CachingPolicy.BEHIND);
UserAccount userAccount3 = new UserAccount("003", "Adam", "He likes food.");
UserAccount userAccount4 = new UserAccount("004", "Rita", "She hates cats.");
UserAccount userAccount5 = new UserAccount("005", "Isaac", "He is allergic to mustard.");
var userAccount3 = new UserAccount("003", "Adam", "He likes food.");
var userAccount4 = new UserAccount("004", "Rita", "She hates cats.");
var userAccount5 = new UserAccount("005", "Isaac", "He is allergic to mustard.");
AppManager.save(userAccount3);
AppManager.save(userAccount4);
@ -152,9 +152,9 @@ public class App {
AppManager.initCachingPolicy(CachingPolicy.ASIDE);
LOGGER.info(AppManager.printCacheContent());
UserAccount userAccount3 = new UserAccount("003", "Adam", "He likes food.");
UserAccount userAccount4 = new UserAccount("004", "Rita", "She hates cats.");
UserAccount userAccount5 = new UserAccount("005", "Isaac", "He is allergic to mustard.");
var userAccount3 = new UserAccount("003", "Adam", "He likes food.");
var userAccount4 = new UserAccount("004", "Rita", "She hates cats.");
var userAccount5 = new UserAccount("005", "Isaac", "He is allergic to mustard.");
AppManager.save(userAccount3);
AppManager.save(userAccount4);
AppManager.save(userAccount5);

19
caching/src/main/java/com/iluwatar/caching/AppManager.java
View File

@ -24,6 +24,7 @@
package com.iluwatar.caching;
import java.text.ParseException;
import java.util.Optional;
/**
* AppManager helps to bridge the gap in communication between the main class and the application's
@ -116,16 +117,12 @@ public final class AppManager {
* Cache-Aside find user account helper.
*/
private static UserAccount findAside(String userId) {
UserAccount userAccount = CacheStore.get(userId);
if (userAccount != null) {
return userAccount;
}
userAccount = DbManager.readFromDb(userId);
if (userAccount != null) {
CacheStore.set(userId, userAccount);
}
return userAccount;
return Optional.ofNullable(CacheStore.get(userId))
.or(() -> {
Optional<UserAccount> userAccount = Optional.ofNullable(DbManager.readFromDb(userId));
userAccount.ifPresent(account -> CacheStore.set(userId, account));
return userAccount;
})
.orElse(null);
}
}

29
caching/src/main/java/com/iluwatar/caching/CacheStore.java
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@ -24,6 +24,8 @@
package com.iluwatar.caching;
import java.util.List;
import java.util.Optional;
import java.util.stream.Collectors;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@ -34,7 +36,7 @@ public class CacheStore {
private static final Logger LOGGER = LoggerFactory.getLogger(CacheStore.class);
static LruCache cache;
private static LruCache cache;
private CacheStore() {
}
@ -134,27 +136,22 @@ public class CacheStore {
*/
public static void flushCache() {
LOGGER.info("# flushCache...");
if (null == cache) {
return;
}
List<UserAccount> listOfUserAccounts = cache.getCacheDataInListForm();
for (UserAccount userAccount : listOfUserAccounts) {
DbManager.upsertDb(userAccount);
}
Optional.ofNullable(cache)
.map(LruCache::getCacheDataInListForm)
.orElse(List.of())
.forEach(DbManager::updateDb);
}
/**
* Print user accounts.
*/
public static String print() {
List<UserAccount> listOfUserAccounts = cache.getCacheDataInListForm();
StringBuilder sb = new StringBuilder();
sb.append("\n--CACHE CONTENT--\n");
for (UserAccount userAccount : listOfUserAccounts) {
sb.append(userAccount.toString() + "\n");
}
sb.append("----\n");
return sb.toString();
return Optional.ofNullable(cache)
.map(LruCache::getCacheDataInListForm)
.orElse(List.of())
.stream()
.map(userAccount -> userAccount.toString() + "\n")
.collect(Collectors.joining("", "\n--CACHE CONTENT--\n", "----\n"));
}
/**

3
caching/src/main/java/com/iluwatar/caching/DbManager.java
View File

@ -25,7 +25,6 @@ package com.iluwatar.caching;
import com.iluwatar.caching.constants.CachingConstants;
import com.mongodb.MongoClient;
import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.model.UpdateOptions;
import java.text.ParseException;
@ -87,7 +86,7 @@ public final class DbManager {
e.printStackTrace();
}
}
FindIterable<Document> iterable = db
var iterable = db
.getCollection(CachingConstants.USER_ACCOUNT)
.find(new Document(CachingConstants.USER_ID, userId));
if (iterable == null) {

12
caching/src/main/java/com/iluwatar/caching/LruCache.java
View File

@ -67,7 +67,7 @@ public class LruCache {
*/
public UserAccount get(String userId) {
if (cache.containsKey(userId)) {
Node node = cache.get(userId);
var node = cache.get(userId);
remove(node);
setHead(node);
return node.userAccount;
@ -111,12 +111,12 @@ public class LruCache {
*/
public void set(String userId, UserAccount userAccount) {
if (cache.containsKey(userId)) {
Node old = cache.get(userId);
var old = cache.get(userId);
old.userAccount = userAccount;
remove(old);
setHead(old);
} else {
Node newNode = new Node(userId, userAccount);
var newNode = new Node(userId, userAccount);
if (cache.size() >= capacity) {
LOGGER.info("# Cache is FULL! Removing {} from cache...", end.userId);
cache.remove(end.userId); // remove LRU data from cache.
@ -137,7 +137,7 @@ public class LruCache {
* Invalidate cache for user.
*/
public void invalidate(String userId) {
Node toBeRemoved = cache.remove(userId);
var toBeRemoved = cache.remove(userId);
if (toBeRemoved != null) {
LOGGER.info("# {} has been updated! Removing older version from cache...", userId);
remove(toBeRemoved);
@ -165,8 +165,8 @@ public class LruCache {
* Returns cache data in list form.
*/
public List<UserAccount> getCacheDataInListForm() {
List<UserAccount> listOfCacheData = new ArrayList<>();
Node temp = head;
var listOfCacheData = new ArrayList<UserAccount>();
var temp = head;
while (temp != null) {
listOfCacheData.add(temp.userAccount);
temp = temp.next;