迭代器模式

Folgerjun · web-flow · commit 28d908195534 · 2018-03-12T10:43:08.000+08:00
迭代器模式
diff --git a/java-des/src/com/java/design/iterator/Iterator.java b/java-des/src/com/java/design/iterator/Iterator.java
@@ -0,0 +1,12 @@
+package com.java.design.iterator;
+
+public interface Iterator {
+
+	Object next();
+
+	void first();
+
+	void last();
+
+	boolean hasNext();
+}
diff --git a/java-des/src/com/java/design/iterator/IteratorImpl.java b/java-des/src/com/java/design/iterator/IteratorImpl.java
@@ -0,0 +1,36 @@
+package com.java.design.iterator;
+
+public class IteratorImpl implements Iterator {
+
+	private List list;
+
+	private Integer index;
+
+	public IteratorImpl(List list) {
+		index = 0;
+		this.list = list;
+	}
+
+	@Override
+	public Object next() {
+		Object object = list.get(index);
+		index++;
+		return object;
+	}
+
+	@Override
+	public void first() {
+		index = 0;
+	}
+
+	@Override
+	public void last() {
+		index = list.getSize();
+	}
+
+	@Override
+	public boolean hasNext() {
+		return index < list.getSize();
+	}
+
+}
diff --git a/java-des/src/com/java/design/iterator/IteratorPattern.java b/java-des/src/com/java/design/iterator/IteratorPattern.java
@@ -0,0 +1,35 @@
+package com.java.design.iterator;
+
+/**
+ * 迭代器模式（Iterator）-----> 提供一种方法顺序访问一个聚合对象中的各种元素，而又不暴露该对象的内部表示。
+ * 
+ * @author Administrator
+ *
+ */
+public class IteratorPattern {
+
+	public static void main(String[] args) {
+
+		List list = new ListImpl();
+		list.add("a");
+		list.add("b");
+		list.add("c");
+		list.add("d");
+
+		// 第一种迭代方式
+		Iterator iterator = list.iterator();
+		while (iterator.hasNext()) {
+
+			System.out.println(iterator.next());
+		}
+
+		System.out.println("----------------------");
+		// 第二种迭代方式
+		for (int i = 0; i < list.getSize(); i++) {
+
+			System.out.println(list.get(i));
+		}
+
+	}
+
+}
diff --git a/java-des/src/com/java/design/iterator/List.java b/java-des/src/com/java/design/iterator/List.java
@@ -0,0 +1,12 @@
+package com.java.design.iterator;
+
+public interface List {
+
+	Iterator iterator();
+
+	Object get(Integer index);
+
+	Integer getSize();
+
+	void add(Object obj);
+}
diff --git a/java-des/src/com/java/design/iterator/ListImpl.java b/java-des/src/com/java/design/iterator/ListImpl.java
@@ -0,0 +1,39 @@
+package com.java.design.iterator;
+
+public class ListImpl implements List {
+
+	private Object[] list;
+
+	private Integer index;
+
+	private Integer size;
+
+	public ListImpl() {
+
+		index = 0;
+		size = 0;
+		list = new Object[100];
+	}
+
+	@Override
+	public Iterator iterator() {
+		return new IteratorImpl(this);
+	}
+
+	@Override
+	public Object get(Integer index) {
+		return list[index];
+	}
+
+	@Override
+	public Integer getSize() {
+		return this.size;
+	}
+
+	@Override
+	public void add(Object obj) {
+
+		list[index++] = obj;
+		size++;
+	}
+}
