新增多例模式

FENG-MASTER · FENG-MASTER · commit 7d6fe489b4e0 · 2017-09-26T22:56:43.000+08:00
diff --git a/src/com/github/fengmaster/design/pattern/factory/absfactory/factory/SouthernFactory.java b/src/com/github/fengmaster/design/pattern/factory/absfactory/factory/SouthernFactory.java
@@ -12,6 +12,7 @@
 public class SouthernFactory implements IAbsFactory {
     @Override
     public IFruit createFruit() {
+
         return new TropicalFruit();
     }
 
diff --git a/src/com/github/fengmaster/design/pattern/singleton/Multiton/Multiton1.java b/src/com/github/fengmaster/design/pattern/singleton/Multiton/Multiton1.java
@@ -0,0 +1,58 @@
+package com.github.fengmaster.design.pattern.singleton.Multiton;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+/**
+ * Created by Feng-master on 2017/9/26.
+ * 单例模式拓展:多例模式
+ * <p>
+ * 应用场景:线程池等其他相关的资源场景
+ */
+public class Multiton1 {
+
+    private static final int num = 5;
+    private static List<Multiton1> multiton1List = new ArrayList<>();
+    private static Random random = new Random();
+
+    static {
+        for (int i = 0; i < num; i++) {
+            multiton1List.add(new Multiton1(i));
+        }
+
+    }
+
+    private Multiton1(int i) {
+        System.out.println("new Multiton1 index:"+i);
+
+    }
+
+    public static Multiton1 getInstance() {
+        return multiton1List.get(random.nextInt(num));
+    }
+
+    public static void main(String args[]){
+        //测试多线程环境下情况
+        ExecutorService executorService = Executors.newFixedThreadPool(20);
+
+        for (int i=0;i<30;i++){
+            executorService.execute(new Runnable() {
+                @Override
+                public void run() {
+                    for (int i=0;i<30;i++){
+                        Multiton1 multiton1=Multiton1.getInstance();
+                    }
+
+                }
+            });
+        }
+
+
+
+    }
+
+
+}
diff --git a/src/com/github/fengmaster/design/pattern/singleton/Multiton/Multiton2.java b/src/com/github/fengmaster/design/pattern/singleton/Multiton/Multiton2.java
@@ -0,0 +1,62 @@
+package com.github.fengmaster.design.pattern.singleton.Multiton;
+
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+/**
+ * Created by Feng-master on 2017/9/26.
+ * 单例模式拓展:多例模式
+ * <p>
+ * 应用场景:线程池等其他相关的资源场景
+ */
+public class Multiton2 {
+
+    private static final int num = 5;
+    private static List<Multiton2> multiton2List = Nested.list;
+    private static Random random = new Random();
+    private Multiton2() {
+        System.out.println("new Multiton2");
+    }
+
+    public static Multiton2 getInstance() {
+        return multiton2List.get(random.nextInt(num));
+    }
+
+
+    public static class Nested {
+
+        private static List<Multiton2> list = new CopyOnWriteArrayList<>();
+
+        static {
+            for (int i = 0; i < num; i++) {
+                list.add(new Multiton2());
+            }
+
+        }
+
+    }
+
+    public static void main(String args[]){
+        //测试多线程环境下情况
+        ExecutorService executorService = Executors.newFixedThreadPool(20);
+
+        for (int i=0;i<30;i++){
+            executorService.execute(new Runnable() {
+                @Override
+                public void run() {
+                    for (int i=0;i<30;i++){
+                        Multiton2 multiton2=Multiton2.getInstance();
+                    }
+
+                }
+            });
+        }
+
+
+
+    }
+
+}
diff --git a/src/com/github/fengmaster/design/pattern/singleton/Singleton1.java b/src/com/github/fengmaster/design/pattern/singleton/Singleton1.java
@@ -6,6 +6,12 @@
  *
  * 缺点:有时候本单例根本用不到,但还是会创建对象,占用空间
  * 优点:简单,且适用于多线程环境
+ *
+ * {@link Singleton3}和第三种方法区别在于,1版本的单例模式,只要这个class被类加载器加载后,就会创建对象
+ * 而3版本的单例模式,就算class被加载,也不会创建对象,只有在显式调用了{@link Singleton3#getInstance()}函数的时候
+ * 才会创建单例对象
+ *
+ *
  */
 public class Singleton1 {
 

Original file line number	Diff line number	Diff line change
`@@ -12,6 +12,7 @@`
`12`	`12`	`public class SouthernFactory implements IAbsFactory {`
`13`	`13`	`@Override`
`14`	`14`	`public IFruit createFruit() {`
	`15`	`+`
`15`	`16`	`return new TropicalFruit();`
`16`	`17`	`}`
`17`	`18`