add code

code/Design_Pattern/装饰者模式/Decorator.java

@@ -0,0 +1,15 @@
+package Design_Pattern.装饰者模式;
+
+public class Decorator implements Sourceable{
+    private Sourceable source;
+
+    public Decorator(Sourceable source) {
+        this.source = source;
+    }
+
+    @Override
+    public void createComputer() {
+        source.createComputer();
+        System.out.println("make system.");
+    }
+}

code/Design_Pattern/装饰者模式/Source.java

@@ -0,0 +1,8 @@
+package Design_Pattern.装饰者模式;
+
+public class Source implements Sourceable{
+    @Override
+    public void createComputer() {
+        System.out.println("create computer by Source.");
+    }
+}

code/Design_Pattern/装饰者模式/Sourceable.java

@@ -0,0 +1,5 @@
+package Design_Pattern.装饰者模式;
+
+public interface Sourceable {
+    public void createComputer();
+}

code/Design_Pattern/装饰者模式/Test.java

@@ -0,0 +1,9 @@
+package Design_Pattern.装饰者模式;
+
+public class Test {
+    public static void main(String[] args) {
+        Sourceable source=new Source();
+        Sourceable obj=new Decorator(source);
+        obj.createComputer();
+    }
+}