problem02 单例

Author: yangrubing

swordForOffer/pom.xml

@@ -1,25 +1,25 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <modelVersion>4.0.0</modelVersion>
-
-  <groupId>com.netease.yangrubing</groupId>
-  <artifactId>swordForOffer</artifactId>
-  <version>0.0.1-SNAPSHOT</version>
-  <packaging>jar</packaging>
-
-  <name>swordForOffer</name>
-  <url>http://maven.apache.org</url>
-
-  <properties>
-    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-  </properties>
-
-  <dependencies>
-    <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <version>3.8.1</version>
-      <scope>test</scope>
-    </dependency>
-  </dependencies>
-</project>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>com.netease.yangrubing</groupId>
+  <artifactId>swordForOffer</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+  <packaging>jar</packaging>
+
+  <name>swordForOffer</name>
+  <url>http://maven.apache.org</url>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>4.7</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+</project>

swordForOffer/src/main/java/com/netease/yangrubing/swordForOffer/App.java

@@ -0,0 +1,24 @@
+package problem02;
+
+/**
+ * 单例模式，采用静态类的实现方式
+ * @author bjyangrubing
+ * 
+ */
+public class SingletonClass
+{
+	/**set the construtor private*/
+	private SingletonClass()
+	{
+	}
+
+	private static class SingletonHolder
+	{
+		private static final SingletonClass INSTANCE = new SingletonClass();
+	}
+
+	public static SingletonClass newInstance()
+	{
+		return SingletonHolder.INSTANCE;
+	}
+}

swordForOffer/src/main/java/problem02/SingletonClass.java

@@ -0,0 +1,19 @@
+package problem02;
+
+import org.junit.Test;
+
+import junit.framework.Assert;
+import problem02.SingletonClass;
+
+public class SingletonClassTest
+{
+	@Test
+	public void test()
+	{
+		SingletonClass singletonClass1 = SingletonClass.newInstance();
+
+		SingletonClass singletonClass2 = SingletonClass.newInstance();
+
+		Assert.assertEquals(singletonClass1, singletonClass2);
+	}
+}