后面的十种模式，消化起来还是比较吃力的

Author: gui0923

.idea/compiler.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_8">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_6">
     <output url="file://$MODULE_DIR$/target/classes" />
     <output-test url="file://$MODULE_DIR$/target/test-classes" />
     <content url="file://$MODULE_DIR$">
@@ -11,7 +11,5 @@
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
-    <orderEntry type="library" name="Maven: mysql:mysql-connector-java:5.1.21" level="project" />
-    <orderEntry type="library" name="Maven: org.apache.commons:commons-lang3:3.7" level="project" />
   </component>
 </module>

.idea/libraries/Maven__mysql_mysql_connector_java_5_1_21.xml

@@ -8,16 +8,16 @@
     <artifactId>DisignPattern</artifactId>
     <version>1.0-SNAPSHOT</version>
 
-    <dependencies>
-        <dependency>
-            <groupId>mysql</groupId>
-            <artifactId>mysql-connector-java</artifactId>
-            <version>5.1.21</version>
-        </dependency>
-        <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-lang3</artifactId>
-            <version>3.7</version>
-        </dependency>
-    </dependencies>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.6</source>
+                    <target>1.6</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
 </project>

.idea/libraries/Maven__org_apache_commons_commons_lang3_3_7.xml

@@ -0,0 +1,6 @@
+观察者模式(Observer)
+包括这个模式在内的接下来的四个模式,都是类和类之间的关系,不涉及到继承,学的时候应该 记得
+归纳,记得本文最开始的那个图。观察者模式很好理解,类似于邮件订阅和 RSS 订阅,当我们浏览一
+些博客或 wiki 时,经常会看到 RSS 图标,就这的意思是,当你订阅了该文章,如果后续有更新,会及
+时通知你。其实,简单来讲就一句话:当一个对象变化时,其它依赖该对象的对象都会收到通知,并且
+随着变化!对象之间是一种一对多的关系。

DisignPattern.iml

@@ -0,0 +1,26 @@
+package com.gl.disign.pattern15.observer;
+
+import java.util.Enumeration;
+import java.util.Vector;
+
+public abstract class AbstractSubject implements Subject {
+    private Vector<Observer> vector = new Vector<Observer>();
+    @Override
+    public void add(Observer observer) {
+        vector.add(observer);
+    }
+
+    @Override
+    public void del(Observer observer) {
+        vector.remove(observer);
+    }
+
+    @Override
+    public void notifyObservers() {
+        Enumeration<Observer> elements = vector.elements();
+        while (elements.hasMoreElements()) {
+            elements.nextElement().update();
+        }
+    }
+
+}

pom.xml

@@ -0,0 +1,9 @@
+package com.gl.disign.pattern15.observer;
+
+public class MySubject extends AbstractSubject {
+    @Override
+    public void operation() {
+        System.out.println("update selef!");
+        notifyObservers();
+    }
+}

src/main/java/com/gl/disign/pattern15/Oberver.txt

@@ -0,0 +1,5 @@
+package com.gl.disign.pattern15.observer;
+
+public interface Observer {
+    public void update();
+}

src/main/java/com/gl/disign/pattern15/observer/AbstractSubject.java

@@ -0,0 +1,8 @@
+package com.gl.disign.pattern15.observer;
+
+public class Observer1 implements Observer {
+    @Override
+    public void update() {
+        System.out.println("observer1 has received!");
+    }
+}