迭代器模式Iterator入门:https://blog.csdn.net/dengjili/article/details/79666954
多个Iterator顺序输出(先进先出)
Iterator1:a
Iterator2:1,2
Iterator3:x,y,z
输出结果:a,1,2,x,y,z
管理器
package headfirst.hd.iterator.eg3;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class IteratorManager<T> {
private List<Iterator<T>> list = new ArrayList<Iterator<T>>();
public void addIterator(Iterator<T> it) {
list.add(it);
}
public Iterator<T> iterator() {
List<T> temp = new ArrayList<T>();
for (Iterator<T> it : list) {
while (it.hasNext()) {
T t = it.next();
temp.add(t);
}
}
return temp.iterator();
}
}
测试
package headfirst.hd.iterator.eg3;
import java.util.Arrays;
import java.util.Iterator;
public class TestIterator {
public static void main(String[] args) {
Iterator<String> it1 = Arrays.asList("a").iterator();
Iterator<String> it2 = Arrays.asList("1", "2").iterator();
Iterator<String> it3 = Arrays.asList("x", "y", "z").iterator();
IteratorManager<String> im = new IteratorManager<>();
im.addIterator(it1);
im.addIterator(it2);
im.addIterator(it3);
Iterator<String> iterator = im.iterator();
while (iterator.hasNext()) {
String string = (String) iterator.next();
System.out.println(string);
}
}
}
测试结果
a
1
x
2
y
z
多个Iterator逆序输出(先进后出)
Iterator1:a
Iterator2:1,2
Iterator3:x,y,z
输出结果:x,y,z,1,2,a
管理器
package headfirst.hd.iterator.eg3;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Stack;
public class IteratorManagerStack<T> {
private Stack<Iterator<T>> stack = new Stack<Iterator<T>>();
public void addIterator(Iterator<T> it) {
stack.add(it);
}
public Iterator<T> iterator() {
List<T> temp = new ArrayList<T>();
while (!stack.isEmpty()) {
Iterator<T> it = stack.pop();
while (it.hasNext()) {
T t = it.next();
temp.add(t);
}
}
return temp.iterator();
}
}
测试
package headfirst.hd.iterator.eg3;
import java.util.Arrays;
import java.util.Iterator;
public class TestIteratorStack {
public static void main(String[] args) {
Iterator<String> it1 = Arrays.asList("a").iterator();
Iterator<String> it2 = Arrays.asList("1", "2").iterator();
Iterator<String> it3 = Arrays.asList("x", "y", "z").iterator();
IteratorManagerStack<String> im = new IteratorManagerStack<>();
im.addIterator(it1);
im.addIterator(it2);
im.addIterator(it3);
Iterator<String> iterator = im.iterator();
while (iterator.hasNext()) {
String string = (String) iterator.next();
System.out.println(string);
}
}
}
测试结果
x
y
z
1
2
a
多个Iterator交替输出(按列优先输出)
Iterator1:a
Iterator2:1,2
Iterator3:x,y,z
输出结果:a,1,x,2,y,z
管理器
package headfirst.hd.iterator.eg3;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class IteratorManagerCross<T> {
private List<Iterator<T>> list = new ArrayList<Iterator<T>>();
public void addIterator(Iterator<T> it) {
list.add(it);
}
public Iterator<T> iterator() {
List<T> temp = new ArrayList<T>();
int size = list.size();
boolean isOver = true;
while (isOver) {
isOver = false;
for (int i = 0; i < size; i++) {
Iterator<T> iterator = list.get(i);
if (iterator.hasNext()) {
temp.add(iterator.next());
isOver = true;
}
}
}
return temp.iterator();
}
}
测试
package headfirst.hd.iterator.eg3;
import java.util.Arrays;
import java.util.Iterator;
public class TestIteratorCross {
public static void main(String[] args) {
Iterator<String> it1 = Arrays.asList("a").iterator();
Iterator<String> it2 = Arrays.asList("1", "2").iterator();
Iterator<String> it3 = Arrays.asList("x", "y", "z").iterator();
IteratorManagerCross<String> im = new IteratorManagerCross<>();
im.addIterator(it1);
im.addIterator(it2);
im.addIterator(it3);
Iterator<String> iterator = im.iterator();
while (iterator.hasNext()) {
String string = (String) iterator.next();
System.out.println(string);
}
}
}
测试结果
a
1
x
2
y
z
组合模式与迭代器的整合
具体链接:https://blog.csdn.net/dengjili/article/details/79705777
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