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checkstyle fixes - docs, indent etc

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This commit is contained in:
zafarella 2015-09-24 01:01:51 -04:00
parent 6735c81b52
commit 36809537d9
6 changed files with 132 additions and 110 deletions
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69
singleton/src/main/java/com/iluwatar/singleton/App.java
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@ -1,3 +1,6 @@
/**
* Singleton pattern.
*/
package com.iluwatar.singleton;
/**
@ -16,40 +19,40 @@ package com.iluwatar.singleton;
*/
public class App {
/**
* Program entry point
* @param args command line args
*/
public static void main(String[] args) {
/**
* Program entry point
* @param args command line args
*/
public static void main(String[] args) {
// eagerly initialized singleton
IvoryTower ivoryTower1 = IvoryTower.getInstance();
IvoryTower ivoryTower2 = IvoryTower.getInstance();
System.out.println("ivoryTower1=" + ivoryTower1);
System.out.println("ivoryTower2=" + ivoryTower2);
// eagerly initialized singleton
IvoryTower ivoryTower1 = IvoryTower.getInstance();
IvoryTower ivoryTower2 = IvoryTower.getInstance();
System.out.println("ivoryTower1=" + ivoryTower1);
System.out.println("ivoryTower2=" + ivoryTower2);
// lazily initialized singleton
ThreadSafeLazyLoadedIvoryTower threadSafeIvoryTower1 = ThreadSafeLazyLoadedIvoryTower
.getInstance();
ThreadSafeLazyLoadedIvoryTower threadSafeIvoryTower2 = ThreadSafeLazyLoadedIvoryTower
.getInstance();
System.out.println("threadSafeIvoryTower1=" + threadSafeIvoryTower1);
System.out.println("threadSafeIvoryTower2=" + threadSafeIvoryTower2);
// lazily initialized singleton
ThreadSafeLazyLoadedIvoryTower threadSafeIvoryTower1 = ThreadSafeLazyLoadedIvoryTower
.getInstance();
ThreadSafeLazyLoadedIvoryTower threadSafeIvoryTower2 = ThreadSafeLazyLoadedIvoryTower
.getInstance();
System.out.println("threadSafeIvoryTower1=" + threadSafeIvoryTower1);
System.out.println("threadSafeIvoryTower2=" + threadSafeIvoryTower2);
// enum singleton
EnumIvoryTower enumIvoryTower1 = EnumIvoryTower.INSTANCE;
EnumIvoryTower enumIvoryTower2 = EnumIvoryTower.INSTANCE;
System.out.println("enumIvoryTower1=" + enumIvoryTower1);
System.out.println("enumIvoryTower2=" + enumIvoryTower2);
InitializingOnDemandHolderIdiom demandHolderIdiom = InitializingOnDemandHolderIdiom.getInstance();
System.out.println(demandHolderIdiom);
InitializingOnDemandHolderIdiom demandHolderIdiom2 = InitializingOnDemandHolderIdiom.getInstance();
System.out.println(demandHolderIdiom2);
ThreadSafeDoubleCheckLocking dcl1 = ThreadSafeDoubleCheckLocking.getInstance();
System.out.println(dcl1);
ThreadSafeDoubleCheckLocking dcl2 = ThreadSafeDoubleCheckLocking.getInstance();
System.out.println(dcl2);
}
// enum singleton
EnumIvoryTower enumIvoryTower1 = EnumIvoryTower.INSTANCE;
EnumIvoryTower enumIvoryTower2 = EnumIvoryTower.INSTANCE;
System.out.println("enumIvoryTower1=" + enumIvoryTower1);
System.out.println("enumIvoryTower2=" + enumIvoryTower2);
InitializingOnDemandHolderIdiom demandHolderIdiom = InitializingOnDemandHolderIdiom.getInstance();
System.out.println(demandHolderIdiom);
InitializingOnDemandHolderIdiom demandHolderIdiom2 = InitializingOnDemandHolderIdiom.getInstance();
System.out.println(demandHolderIdiom2);
ThreadSafeDoubleCheckLocking dcl1 = ThreadSafeDoubleCheckLocking.getInstance();
System.out.println(dcl1);
ThreadSafeDoubleCheckLocking dcl2 = ThreadSafeDoubleCheckLocking.getInstance();
System.out.println(dcl2);
}
}

11
singleton/src/main/java/com/iluwatar/singleton/EnumIvoryTower.java
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@ -1,13 +1,14 @@
/**
* Enum Singleton class.
* Effective Java 2nd Edition (Joshua Bloch) p. 18
*/
package com.iluwatar.singleton;
/**
*
* Enum Singleton class.
* Effective Java 2nd Edition (Joshua Bloch) p. 18
*
* Enum based singleton implementation.
*/
public enum EnumIvoryTower {
INSTANCE;
@Override

36
singleton/src/main/java/com/iluwatar/singleton/InitializingOnDemandHolderIdiom.java
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@ -1,36 +1,38 @@
/**
* Singleton pattern.
*/
package com.iluwatar.singleton;
import java.io.Serializable;
/**
* The Initialize-on-demand-holder idiom is a secure way of
* The Initialize-on-demand-holder idiom is a secure way of
* creating lazy initialized singleton object in Java.
* refer to "The CERT Oracle Secure Coding Standard for Java"
* By Dhruv Mohindra, Robert C. Seacord p.378
* <p>
* <p/>
* Singleton objects usually are heavy to create and sometimes need to serialize them.
* This class also shows how to preserve singleton in serialized version of singleton.
*
* @author mortezaadi@gmail.com
*
* @author mortezaadi@gmail.com
*/
public class InitializingOnDemandHolderIdiom implements Serializable{
public class InitializingOnDemandHolderIdiom implements Serializable {
private static final long serialVersionUID = 1L;
private static final long serialVersionUID = 1L;
private static class HelperHolder {
public static final InitializingOnDemandHolderIdiom INSTANCE = new InitializingOnDemandHolderIdiom();
}
private InitializingOnDemandHolderIdiom() {
}
public static InitializingOnDemandHolderIdiom getInstance() {
return HelperHolder.INSTANCE;
}
public static InitializingOnDemandHolderIdiom getInstance() {
return HelperHolder.INSTANCE;
}
private InitializingOnDemandHolderIdiom() {
}
protected Object readResolve() {
return getInstance();
}
protected Object readResolve() {
return getInstance();
}
private static class HelperHolder {
public static final InitializingOnDemandHolderIdiom INSTANCE = new InitializingOnDemandHolderIdiom();
}
}

31
singleton/src/main/java/com/iluwatar/singleton/IvoryTower.java
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@ -1,20 +1,33 @@
/**
* Singleton pattern.
*/
package com.iluwatar.singleton;
/**
*
* Singleton class.
* Eagerly initialized static instance guarantees thread
* safety.
*
*/
public class IvoryTower {
public final class IvoryTower {
private static IvoryTower instance = new IvoryTower();
/**
* Static to class instance of the class.
*/
private static IvoryTower instance = new IvoryTower();
private IvoryTower() {
}
/**
* Private constructor so nobody can instantiate the class.
*/
private IvoryTower() {
}
public static IvoryTower getInstance() {
return instance;
}
/**
* To be called by user to
* obtain instance of the class.
*
* @return instance of the singleton.
*/
public static IvoryTower getInstance() {
return instance;
}
}

62
singleton/src/main/java/com/iluwatar/singleton/ThreadSafeDoubleCheckLocking.java
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@ -1,41 +1,43 @@
/**
* Singleton pattern.
*
*/
package com.iluwatar.singleton;
/**
* Double check locking
* <p>
* <p/>
* http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html
* <p>
* <p/>
* Broken under Java 1.4.
*
* @author mortezaadi@gmail.com
*
* @author mortezaadi@gmail.com
*/
public class ThreadSafeDoubleCheckLocking {
private static volatile ThreadSafeDoubleCheckLocking INSTANCE;
/**
* private constructor to prevent client from instantiating.
*
*/
private ThreadSafeDoubleCheckLocking() {
//to prevent instantiating by Reflection call
if(INSTANCE != null)
throw new IllegalStateException("Already initialized.");
}
public static ThreadSafeDoubleCheckLocking getInstance() {
//local variable increases performance by 25 percent
//Joshua Bloch "Effective Java, Second Edition", p. 283-284
ThreadSafeDoubleCheckLocking result = INSTANCE;
if (result == null) {
synchronized (ThreadSafeDoubleCheckLocking.class) {
result = INSTANCE;
if (result == null) {
INSTANCE = result = new ThreadSafeDoubleCheckLocking();
}
}
}
return result;
}
private static volatile ThreadSafeDoubleCheckLocking INSTANCE;
/**
* private constructor to prevent client from instantiating.
*/
private ThreadSafeDoubleCheckLocking() {
//to prevent instantiating by Reflection call
if (INSTANCE != null)
throw new IllegalStateException("Already initialized.");
}
public static ThreadSafeDoubleCheckLocking getInstance() {
//local variable increases performance by 25 percent
//Joshua Bloch "Effective Java, Second Edition", p. 283-284
ThreadSafeDoubleCheckLocking result = INSTANCE;
if (result == null) {
synchronized (ThreadSafeDoubleCheckLocking.class) {
result = INSTANCE;
if (result == null) {
INSTANCE = result = new ThreadSafeDoubleCheckLocking();
}
}
}
return result;
}
}

33
singleton/src/main/java/com/iluwatar/singleton/ThreadSafeLazyLoadedIvoryTower.java
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@ -1,28 +1,29 @@
/**
* Singleton pattern.
*/
package com.iluwatar.singleton;
/**
*
* Thread-safe Singleton class.
* The instance is lazily initialized and thus needs synchronization
* mechanism.
*
*/
public class ThreadSafeLazyLoadedIvoryTower {
private static ThreadSafeLazyLoadedIvoryTower instance = null;
private ThreadSafeLazyLoadedIvoryTower() {
}
private static ThreadSafeLazyLoadedIvoryTower instance = null;
public synchronized static ThreadSafeLazyLoadedIvoryTower getInstance() {
/*
* The instance gets created only when it is called for first time.
* Lazy-loading
*/
if (instance == null) {
instance = new ThreadSafeLazyLoadedIvoryTower();
}
private ThreadSafeLazyLoadedIvoryTower() {
}
return instance;
}
public synchronized static ThreadSafeLazyLoadedIvoryTower getInstance() {
/*
* The instance gets created only when it is called for first time.
* Lazy-loading
*/
if (instance == null) {
instance = new ThreadSafeLazyLoadedIvoryTower();
}
return instance;
}
}