JAVA设计模式---简单工厂模式
在上一篇策略模式的基础上进一步优化，引出简单工厂模式。
按Object数组中Person的某一属性进行排序，按哪个属性排序的功能抽象为接口，具体由对应策略实现类完成。
这一篇主要是把调用相应策略时改为工厂模式调用，来演示工厂模式的使用。
Person类：
package com.flg.Strategy;
import java.util.Comparator;
/**
* Created with IntelliJ IDEA.
* User: fuliguo
* Date: 12-8-12
* Time: 下午14:12
* 待排序类实现了Comparable接口
* 排序条件由具体策略决定,排序策略实现了Comparator接口
*/
public class Person implements Comparable<Person>{
private String name;//姓名 1
private int age;//年龄 2
private int height;//身高 3
//请关注工厂模式博文，此处会换成工厂方法实现
//private Comparator comparator = new PersonAgeComparator();//按年龄排序
//private Comparator comparator = new PersonHeigthComparator();//按身高排序
// private Comparator comparator = new PersonNameComparator();//按姓名排序
//请关注工厂模式博文，此处会换成工厂方法实现
//工厂方法形式实现
//1，按名称排序策略；2，按年龄排序策略；3，按身高排序策略；
private Comparator comparator = PersonComparatorContext.getComparatorInstance(1);
public Person(String name, int age,int height) {
this.name = name;
this.age = age;
this.height = height;
}
public Person(){}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public int getHeight() {
return height;
}
public void setHeight(int height) {
this.height = height;
}
@Override
/**
* 实现Comparable接口中的comparaTo方法
* 具体排序条件由对应策略实现
*/
public int compareTo(Person o) {
return comparator.compare(this,o);//根据什么排序，由具体策略实现决定
}
}
按姓名进行排序的策略，PersonNameComparator类：
package com.flg.Strategy;
import java.util.Comparator;
/**
* Created with IntelliJ IDEA.
* User: fuliguo
* Date: 12-8-12
* Time: 下午4:05
* To change this template use File | Settings | File Templates.
*/
public class PersonNameComparator implements Comparator<Person> {
@Override
public int compare(Person o1, Person o2) {
return o1.getName().compareToIgnoreCase(o2.getName());//按姓名排序
}
}
获取按姓名排序策略的工厂，PersonNameComparatorFactory类：
package com.flg.Strategy;
import java.util.Comparator;
/**
* Created with IntelliJ IDEA.
* User: fuliguo
* Date: 12-8-13
* Time: 上午12:21
* To change this template use File | Settings | File Templates.
*/
public class PersonNameComparatorFacory extends AbstractPersonComparatorFactory {
@Override
public Comparator getComparatorInstance() {
return new PersonNameComparator();
}
}
按年龄排序的策略，PersonAgeComparator类：
package com.flg.Strategy;
import java.util.Comparator;
/**
* Created with IntelliJ IDEA.
* User: fuliguo
* Date: 12-8-12
* Time: 下午4:07
* 按人的年龄进行比较的策略
*/
public class PersonAgeComparator implements Comparator<Person> {
@Override
public int compare(Person o1, Person o2) {
return o1.getAge()-o2.getAge();//按年龄比较
}
}
获取按年龄排序策略的工厂，PersonAgeComparatorFactory类：
package com.flg.Strategy;
import java.util.Comparator;
/**
* Created with IntelliJ IDEA.
* User: fuliguo
* Date: 12-8-12
* Time: 下午10:44
* To change this template use File | Settings | File Templates.
*/
public class PersonAgeComparatorFactory extends AbstractPersonComparatorFactory {
@Override
public Comparator getComparatorInstance() {
return new PersonAgeComparator();
}
}
按身高排序的策略，PersonHeightComparator类：
package com.flg.Strategy;
import java.util.Comparator;
/**
* Created with IntelliJ IDEA.
* User: fuliguo
* Date: 12-8-12
* Time: 下午4:13
* 按人的高度进行比较的策略
*/
public class PersonHeightComparator implements Comparator<Person> {
@Override
public int compare(Person o1, Person o2) {
return o1.getHeight()-o2.getHeight();//按高度比较
}
}
获取按身高排序策略的工厂，PersonHeightComparatorFactory类：
package com.flg.Strategy;
import java.util.Comparator;
/**
* Created with IntelliJ IDEA.
* User: fuliguo
* Date: 12-8-13
* Time: 上午12:19
* To change this template use File | Settings | File Templates.
*/
public class PersonHeightComparatorFactory extends AbstractPersonComparatorFactory {
@Override
public Comparator getComparatorInstance() {
return new PersonHeightComparator();
}
}
获取排序策略的工厂的抽象类（注意：这里不是抽象工厂的概念），AbstractPersonComparatorFactory类：
package com.flg.Strategy;
import java.util.Comparator;
/**
* Created with IntelliJ IDEA.
* User: fuliguo
* Date: 12-8-12
* Time: 下午4:25
* 获取排序策略的工厂的抽象类
*/
public abstract class AbstractPersonComparatorFactory {
public abstract Comparator getComparatorInstance();
}
根据类型获取排序策略的Context，PersonComparatorContext类：
package com.flg.Strategy;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
/**
* Created with IntelliJ IDEA.
* User: fuliguo
* Date: 12-8-13
* Time: 上午12:45
* 根据类型获取排序策略的Context
*/
public class PersonComparatorContext {
private static Map<Integer,Comparator> context = new HashMap<Integer,Comparator>();
private PersonComparatorContext(){}
public static Comparator getComparatorInstance(int type) {
if(context.get(type)==null){
context.put(type,getComparator(type));
}
return context.get(type);
}
private static Comparator getComparator(int type){
AbstractPersonComparatorFactory factory = null;
switch (type){
case 1: factory = new PersonNameComparatorFacory();break;
case 2: factory = new PersonAgeComparatorFactory();break;
case 3: factory = new PersonHeightComparatorFactory();break;
//默认按名字排序
default: factory = new PersonNameComparatorFacory();break;
}
Comparator comparator = factory.getComparatorInstance();
return comparator;
}
}
测试类，Test类：
package com.flg.Strategy;
import com.flg.*;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* Created with IntelliJ IDEA.
* User: fuliguo
* Date: 12-8-12
* Time: 下午5:07
* To change this template use File | Settings | File Templates.
*/
public class Test {
public Object[] getObjects() {
Object [] objects = new Object[]{
new Person("张三",22,188),
new Person("赵六",19,210),
new Person("王五",30,175),
new Person("李四",10,158)
} ;
return objects;
}
/**
* 控制台输出遍历list对像顺序
*/
public void printObjects(Object[] objects) {
Person p;
for(int i=0;i<objects.length;i++){
p = (Person) objects[i];
System.out.println(p.getName()+"---"+p.getAge()+"---"+p.getHeight());
}
}
public static void main(String [] arg){
Test t = new Test();
Object [] objects = t.getObjects();
t.printObjects(objects);
Arrays.sort(objects);
System.out.println("***********排序后******************");
t.printObjects(objects);
}
}