Java设计模式:组合模式
09 Sep 2014注:本文为译文,原文出处java-design-patterns-in-stories
组合模式是一个相对简单但是在很多设计中都应用非常广泛的模式, 诸如在：SWT, Eclipse Workspace等中都有广泛应用. 它主要生成一个可通过统一方法访问的结构化的树.
类图
下一节的代码实现了下图中的树状结构.
Java代码
import java.util.List;
import java.util.ArrayList;
//Component
interface Component {
public void show();
}
//Composite
class Composite implements Component {
private List<Component> childComponents = new ArrayList<Component>();
public void add(Component component) {
childComponents.add(component);
}
public void remove(Component component) {
childComponents.remove(component);
}
@Override
public void show() {
for (Component component : childComponents) {
component.show();
}
}
}
//leaf
class Leaf implements Component {
String name;
public Leaf(String s){
name = s;
}
public void show() {
System.out.println(name);
}
}
public class CompositeTest {
public static void main(String[] args) {
Leaf leaf1 = new Leaf("1");
Leaf leaf2 = new Leaf("2");
Leaf leaf3 = new Leaf("3");
Leaf leaf4 = new Leaf("4");
Leaf leaf5 = new Leaf("5");
Composite composite1 = new Composite();
composite1.add(leaf1);
composite1.add(leaf2);
Composite composite2 = new Composite();
composite2.add(leaf3);
composite2.add(leaf4);
composite2.add(leaf5);
composite1.add(composite2);
composite1.show();
}
}