Commit dbba1d1

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deeper

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不安全的组合模式

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Lines changed: 2 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -2,6 +2,8 @@`
`2`	`2`
`3`	`3`	`public class Demo {`
`4`	`4`	`public static void main(String[] args) {`
	`5`	`+ // 从下面的例子里面很明显可以看出来 :两个类虽然都实现了共同的抽象,却都是以实现类来new的,这与【依赖倒置】相违背,定义的抽象Component起的作用就不大。`
	`6`	`+ // 为了防止这个问题,不安全的组合模式出现了(虽然不安全,但正确使用也没有多大问题)`
`5`	`7`	`Composite root = new Composite("root");`
`6`	`8`
`7`	`9`	`Composite branch1 = new Composite("branch1");`

Lines changed: 19 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,19 @@`
	`1`	`+package com.ruoxu.pattern.composite.unsafe;`
	`2`	`+/**`
	`3`	`+ * 抽象根节点`
	`4`	`+ */`
	`5`	`+public abstract class Component {`
	`6`	`+ protected String name; // 节点名`
	`7`	`+`
	`8`	`+ public Component(String name) {`
	`9`	`+ this.name = name;`
	`10`	`+ }`
	`11`	`+`
	`12`	`+ public abstract void doSomething();`
	`13`	`+`
	`14`	`+ public abstract void addChild(Component child);`
	`15`	`+`
	`16`	`+ public abstract void removeChild(Component child);`
	`17`	`+`
	`18`	`+ public abstract Component getChild(int index);`
	`19`	`+}`

Lines changed: 50 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,50 @@`
	`1`	`+package com.ruoxu.pattern.composite.unsafe;`
	`2`	`+`
	`3`	`+import java.util.ArrayList;`
	`4`	`+import java.util.List;`
	`5`	`+`
	`6`	`+/**`
	`7`	`+ * 具体枝干节点(相当于文件夹)`
	`8`	`+ */`
	`9`	`+public class Composite extends Component{`
	`10`	`+ private List<Component> components = new ArrayList<>();`
	`11`	`+`
	`12`	`+ public Composite(String name) {`
	`13`	`+ super(name);`
	`14`	`+ }`
	`15`	`+`
	`16`	`+ @Override`
	`17`	`+ public void doSomething() {`
	`18`	`+ System.out.println(name);`
	`19`	`+ if(null != components){`
	`20`	`+ for(Component c: components){`
	`21`	`+ c.doSomething();`
	`22`	`+ }`
	`23`	`+ }`
	`24`	`+ }`
	`25`	`+`
	`26`	`+ /**`
	`27`	`+ * 添加子节点`
	`28`	`+ */`
	`29`	`+ @Override`
	`30`	`+ public void addChild(Component child){`
	`31`	`+ components.add(child);`
	`32`	`+ }`
	`33`	`+`
	`34`	`+ /**`
	`35`	`+ * 移除子节点`
	`36`	`+ */`
	`37`	`+ @Override`
	`38`	`+ public void removeChild(Component child){`
	`39`	`+ components.remove(child);`
	`40`	`+ }`
	`41`	`+`
	`42`	`+ /**`
	`43`	`+ * 获取子节点`
	`44`	`+ */`
	`45`	`+ @Override`
	`46`	`+ public Component getChild(int index){`
	`47`	`+ return components.get(index);`
	`48`	`+ }`
	`49`	`+`
	`50`	`+}`

Lines changed: 21 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,21 @@`
	`1`	`+package com.ruoxu.pattern.composite.unsafe;`
	`2`	`+`
	`3`	`+public class Demo {`
	`4`	`+ public static void main(String[] args) {`
	`5`	`+ Component root = new Composite("root");`
	`6`	`+`
	`7`	`+ Component branch1 = new Composite("branch1");`
	`8`	`+ Component branch2 = new Composite("branch2");`
	`9`	`+`
	`10`	`+ Component leaf1 = new Leaf("leaf1");`
	`11`	`+ Component leaf2 = new Leaf("leaf2");`
	`12`	`+`
	`13`	`+ branch1.addChild(leaf1);`
	`14`	`+ branch2.addChild(leaf2);`
	`15`	`+`
	`16`	`+ root.addChild(branch1);`
	`17`	`+ root.addChild(branch2);`
	`18`	`+`
	`19`	`+ root.doSomething();`
	`20`	`+ }`
	`21`	`+}`

Lines changed: 31 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,31 @@`
	`1`	`+package com.ruoxu.pattern.composite.unsafe;`
	`2`	`+/**`
	`3`	`+ * 叶子结点`
	`4`	`+ */`
	`5`	`+public class Leaf extends Component{`
	`6`	`+`
	`7`	`+ public Leaf(String name) {`
	`8`	`+ super(name);`
	`9`	`+ }`
	`10`	`+`
	`11`	`+ @Override`
	`12`	`+ public void doSomething() {`
	`13`	`+ System.out.println(name);`
	`14`	`+ }`
	`15`	`+`
	`16`	`+ @Override`
	`17`	`+ public void addChild(Component child) {`
	`18`	`+ throw new UnsupportedOperationException("叶子节点没有子节点");`
	`19`	`+ }`
	`20`	`+`
	`21`	`+ @Override`
	`22`	`+ public void removeChild(Component child) {`
	`23`	`+ throw new UnsupportedOperationException("叶子节点没有子节点");`
	`24`	`+ }`
	`25`	`+`
	`26`	`+ @Override`
	`27`	`+ public Component getChild(int index) {`
	`28`	`+ throw new UnsupportedOperationException("叶子节点没有子节点");`
	`29`	`+ }`
	`30`	`+`
	`31`	`+}`

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