疯狂Java

Author: Liberty77

Diff for: .idea/misc.xml

@@ -1,6 +1,12 @@
+import crazy.CrazyTest;
+
 public class Main {
 
     public static void main(String[] args) {
+
+        CrazyTest test1 = new CrazyTest();
+        test1.testMethod();
+
         System.out.println("Hello World!");
     }
 }

Diff for: .idea/uiDesigner.xml

@@ -0,0 +1,72 @@
+package crazy;
+
+/**
+ * Created by Gaol on 2018/6/13.
+ */
+public class CacheImmutale {
+
+    private static int MAX_SIZE = 10;
+
+    //使用数组来缓存已有的实例
+    private static CacheImmutale[]  cache = new CacheImmutale[MAX_SIZE];
+    //记录缓存实例在缓存中的位置，cache[pos-1]是最新缓存的实例
+    private static int pos = 0;
+    private final String name;
+
+    private CacheImmutale(String name) {
+
+        this.name = name;
+    }
+
+    public String getName() {
+
+        return name;
+    }
+
+    public static CacheImmutale valueOf(String name) {
+
+        //遍历已缓存的对象
+        for(int i = 0; i< MAX_SIZE; i++) {
+
+            //如果已有相同实例，则直接返回该缓存实例
+            if(cache[i]  != null && cache[i].getName().equals(name)) {
+                return cache[i];
+            }
+        }
+
+        if(pos == MAX_SIZE) {
+
+            //把缓存的第一个对象覆盖，即把刚刚生成的对象放在缓存池最开始的位置
+            cache[0] = new CacheImmutale(name);
+            //把pos设为1
+            pos = 1;
+
+        } else {
+
+            //把新创建的对象缓存起来，pos 加 1
+            cache[pos++] = new CacheImmutale(name);
+        }
+        return cache[pos-1];
+    }
+
+    public boolean equals(Object obj) {
+
+        if(this == obj) {
+            return true;
+        }
+
+        if(obj != null && obj.getClass() == CacheImmutale.class) {
+            CacheImmutale ci = (CacheImmutale)obj;
+            return name.equals(ci.getName());
+        }
+
+        return false;
+    }
+
+    public int hashCode() {
+
+        return name.hashCode();
+    }
+
+
+}

Diff for: src/Main.java

@@ -0,0 +1,16 @@
+package crazy;
+
+/** 疯狂Java 讲义
+ * Created by Gaol on 2018/6/13.
+ */
+public class CrazyTest {
+
+    Singleton s1 = Singleton.getInstance();
+    Singleton s2 = Singleton.getInstance();
+
+    public void testMethod() {
+
+        System.out.println(s1 == s2);
+    }
+
+}

Diff for: src/crazy/CacheImmutale.java

@@ -0,0 +1,24 @@
+package crazy;
+
+/**
+ * Created by Gaol on 2018/6/13.
+ */
+public class Singleton {
+
+    final String str = "Hello";
+
+    private static Singleton instance;
+
+    private Singleton() {}
+
+    public static Singleton getInstance() {
+
+       if(instance == null) {
+
+         instance = new Singleton();
+      }
+
+       return instance;
+    }
+
+}