小傅哥 | 重学 Java 设计模式：实战迭代器模式「模拟公司组织架构树结构关系，深度迭代遍历人员信息输出场景」

itstack-demo-design-15-00/pom.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http:https://maven.apache.org/POM/4.0.0"
+ xmlns:xsi="http:https://www.w3.org/2001/XMLSchema-instance"
+ xsi:schemaLocation="http:https://maven.apache.org/POM/4.0.0 http:https://maven.apache.org/xsd/maven-4.0.0.xsd">
+ <parent>
+ <artifactId>itstack-demo-design</artifactId>
+ <groupId>org.itstack</groupId>
+ <version>1.0-SNAPSHOT</version>
+ </parent>
+ <modelVersion>4.0.0</modelVersion>
+
+ <artifactId>itstack-demo-design-15-00</artifactId>
+
+
+</project>

itstack-demo-design-15-00/src/main/java/org/itstack/demo/design/group/Employee.java

@@ -0,0 +1,47 @@
+package org.itstack.demo.design.group;
+
+/**
+ * 雇员
+ */
+public class Employee {
+
+ private String uId; // ID
+ private String name; // 姓名
+ private String desc; // 备注
+
+ public Employee(String uId, String name) {
+ this.uId = uId;
+ this.name = name;
+ }
+
+ public Employee(String uId, String name, String desc) {
+ this.uId = uId;
+ this.name = name;
+ this.desc = desc;
+ }
+
+ public String getuId() {
+ return uId;
+ }
+
+ public void setuId(String uId) {
+ this.uId = uId;
+ }
+
+ public String getName() {
+ return name;
+ }
+
+ public void setName(String name) {
+ this.name = name;
+ }
+
+ public String getDesc() {
+ return desc;
+ }
+
+ public void setDesc(String desc) {
+ this.desc = desc;
+ }
+
+}

itstack-demo-design-15-00/src/main/java/org/itstack/demo/design/group/GroupStructure.java

@@ -0,0 +1,103 @@
+package org.itstack.demo.design.group;
+
+import org.itstack.demo.design.lang.Collection;
+import org.itstack.demo.design.lang.Iterator;
+
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+public class GroupStructure implements Collection<Employee, Link> {
+
+ private String groupId; // 组织ID，也是一个组织链的头部ID
+ private String groupName; // 组织名称
+ private Map<String, Employee> employeeMap = new ConcurrentHashMap<String, Employee>(); // 雇员列表
+ private Map<String, List<Link>> linkMap = new ConcurrentHashMap<String, List<Link>>(); // 组织架构关系；id->list
+ private Map<String, String> invertedMap = new ConcurrentHashMap<String, String>(); // 反向关系链
+
+ public GroupStructure(String groupId, String groupName) {
+ this.groupId = groupId;
+ this.groupName = groupName;
+ }
+
+ public boolean add(Employee employee) {
+ return null != employeeMap.put(employee.getuId(), employee);
+ }
+
+ public boolean remove(Employee o) {
+ return null != employeeMap.remove(o.getuId());
+ }
+
+ public boolean addLink(String key, Link link) {
+ invertedMap.put(link.getToId(), link.getFromId());
+ if (linkMap.containsKey(key)) {
+ return linkMap.get(key).add(link);
+ } else {
+ List<Link> links = new LinkedList<Link>();
+ links.add(link);
+ linkMap.put(key, links);
+ return true;
+ }
+ }
+
+ public boolean removeLink(String key) {
+ return null != linkMap.remove(key);
+ }
+
+ public Iterator<Employee> iterator() {
+
+ return new Iterator<Employee>() {
+
+ HashMap<String, Integer> keyMap = new HashMap<String, Integer>();
+
+ int totalIdx = 0;
+ private String fromId = groupId; // 雇员ID，From
+ private String toId = groupId; // 雇员ID，To
+
+ public boolean hasNext() {
+ return totalIdx < employeeMap.size();
+ }
+
+ public Employee next() {
+ List<Link> links = linkMap.get(toId);
+ int cursorIdx = getCursorIdx(toId);
+
+ // 同级节点扫描
+ if (null == links) {
+ cursorIdx = getCursorIdx(fromId);
+ links = linkMap.get(fromId);
+ }
+
+ // 上级节点扫描
+ while (cursorIdx > links.size() - 1) {
+ fromId = invertedMap.get(fromId);
+ cursorIdx = getCursorIdx(fromId);
+ links = linkMap.get(fromId);
+ }
+
+ // 获取节点
+ Link link = links.get(cursorIdx);
+ toId = link.getToId();
+ fromId = link.getFromId();
+ totalIdx++;
+
+ // 返回结果
+ return employeeMap.get(link.getToId());
+ }
+
+ public int getCursorIdx(String key) {
+ int idx = 0;
+ if (keyMap.containsKey(key)) {
+ idx = keyMap.get(key);
+ keyMap.put(key, ++idx);
+ } else {
+ keyMap.put(key, idx);
+ }
+ return idx;
+ }
+ };
+ }
+
+}

itstack-demo-design-15-00/src/main/java/org/itstack/demo/design/group/Link.java

@@ -0,0 +1,32 @@
+package org.itstack.demo.design.group;
+
+/**
+ * 树节点链路
+ */
+public class Link {
+
+ private String fromId; // 雇员ID
+ private String toId; // 雇员ID
+
+ public Link(String fromId, String toId) {
+ this.fromId = fromId;
+ this.toId = toId;
+ }
+
+ public String getFromId() {
+ return fromId;
+ }
+
+ public void setFromId(String fromId) {
+ this.fromId = fromId;
+ }
+
+ public String getToId() {
+ return toId;
+ }
+
+ public void setToId(String toId) {
+ this.toId = toId;
+ }
+
+}

itstack-demo-design-15-00/src/main/java/org/itstack/demo/design/lang/Collection.java

@@ -0,0 +1,15 @@
+package org.itstack.demo.design.lang;
+
+public interface Collection<E, L> extends Iterable<E> {
+
+ boolean add(E e);
+
+ boolean remove(E e);
+
+ boolean addLink(String key, L l);
+
+ boolean removeLink(String key);
+
+ Iterator<E> iterator();
+
+}

itstack-demo-design-15-00/src/main/java/org/itstack/demo/design/lang/Iterable.java

@@ -0,0 +1,7 @@
+package org.itstack.demo.design.lang;
+
+public interface Iterable<E> {
+
+ Iterator<E> iterator();
+
+}

itstack-demo-design-15-00/src/main/java/org/itstack/demo/design/lang/Iterator.java

@@ -0,0 +1,9 @@
+package org.itstack.demo.design.lang;
+
+public interface Iterator<E> {
+
+ boolean hasNext();
+
+ E next();
+
+}

itstack-demo-design-15-00/src/test/java/org/itstack/demo/design/test/ApiTest.java

@@ -0,0 +1,46 @@
+package org.itstack.demo.design.test;
+
+import com.alibaba.fastjson.JSON;
+import org.apache.commons.lang3.StringUtils;
+import org.itstack.demo.design.group.Employee;
+import org.itstack.demo.design.group.GroupStructure;
+import org.itstack.demo.design.group.Link;
+import org.itstack.demo.design.lang.Iterator;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ApiTest {
+
+ private Logger logger = LoggerFactory.getLogger(ApiTest.class);
+
+ @Test
+ public void test_iterator() {
+ GroupStructure groupStructure = new GroupStructure("1", "小傅哥");
+ groupStructure.add(new Employee("2", "花花", "二级部门"));
+ groupStructure.add(new Employee("3", "豆包", "二级部门"));
+ groupStructure.add(new Employee("4", "蹦蹦", "三级部门"));
+ groupStructure.add(new Employee("5", "大烧", "三级部门"));
+ groupStructure.add(new Employee("6", "虎哥", "四级部门"));
+ groupStructure.add(new Employee("7", "玲姐", "四级部门"));
+ groupStructure.add(new Employee("8", "秋雅", "四级部门"));
+
+ groupStructure.addLink("1", new Link("1", "2"));
+ groupStructure.addLink("1", new Link("1", "3"));
+
+ groupStructure.addLink("2", new Link("2", "4"));
+ groupStructure.addLink("2", new Link("2", "5"));
+
+ groupStructure.addLink("5", new Link("5", "6"));
+ groupStructure.addLink("5", new Link("5", "7"));
+ groupStructure.addLink("5", new Link("5", "8"));
+
+ Iterator<Employee> iterator = groupStructure.iterator();
+ while (iterator.hasNext()) {
+ Employee employee = iterator.next();
+ logger.info("{}，雇员 Id：{} Name：{}", employee.getDesc(), employee.getuId(), employee.getName());
+ }
+
+ }
+
+}

pom.xml

@@ -45,6 +45,7 @@
  <module>itstack-demo-design-14-00</module>
  <module>itstack-demo-design-14-01</module>
  <module>itstack-demo-design-14-02</module>
+ <module>itstack-demo-design-15-00</module>
  </modules>
 
  <dependencies>