add command DP

src/designpattern/command/Command.java

@@ -0,0 +1,41 @@
+package designpattern.command;
+
+import java.util.List;
+
+/**
+ * 用来声明执行操作的接口
+ * 
+ * @author liu yuning
+ *
+ */
+public abstract class Command {
+
+    protected List<Reciever> recievers;
+
+    public Command(List<Reciever> recievers) {
+	this.recievers = recievers;
+    }
+
+    public void addRecievers(Reciever reciever) {
+	this.recievers.add(reciever);
+    }
+
+    public abstract void execute();
+
+}
+
+// 将一个接收者对象绑定于一个动作，调用接收者相应的操作，以实现execute
+class ConcreteCommand extends Command {
+
+    public ConcreteCommand(List<Reciever> recievers) {
+	super(recievers);
+    }
+
+    @Override
+    public void execute() {
+	for (Reciever reciever : recievers) {
+	    reciever.action();
+	}
+    }
+
+}

src/designpattern/command/CommandClient.java

@@ -0,0 +1,29 @@
+package designpattern.command;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 创建一个具体命令对象并设定它的接收者
+ * 
+ * @author liu yuning
+ *
+ */
+public class CommandClient {
+
+    public static void main(String[] args) {
+	List<Reciever> recievers = new ArrayList<Reciever>();
+
+	recievers.add(new RecieverA());
+	recievers.add(new RecieverB());
+	recievers.add(new RecieverC());
+
+	Command command = new ConcreteCommand(recievers);
+	Invoker invoker = new Invoker();
+
+	invoker.setCommand(command);
+	invoker.executeCommand();
+
+    }
+
+}

src/designpattern/command/Invoker.java

@@ -0,0 +1,21 @@
+package designpattern.command;
+
+/**
+ * 要求该命令执行这个请求
+ * 
+ * @author liu yuning
+ *
+ */
+public class Invoker {
+
+    private Command command;
+
+    public void setCommand(Command command) {
+	this.command = command;
+    }
+
+    public void executeCommand() {
+	command.execute();
+    }
+
+}

src/designpattern/command/Reciever.java

@@ -0,0 +1,36 @@
+package designpattern.command;
+
+/**
+ * 知道如何实施与执行一个与请求相关的操作，任何类都可能作为一个接收者。真正执行请求的地方！
+ * 
+ * @author liu yuning
+ *
+ */
+interface Reciever {
+    public void action();
+}
+
+class RecieverA implements Reciever {
+
+    @Override
+    public void action() {
+	System.out.println("RecieverA执行请求！");
+    }
+
+}
+
+class RecieverB implements Reciever {
+
+    @Override
+    public void action() {
+	System.out.println("RecieverB执行请求！");
+    }
+}
+
+class RecieverC implements Reciever {
+
+    @Override
+    public void action() {
+	System.out.println("RecieverC执行请求！");
+    }
+}