使用工厂方法模式实现各种不同分润规则

本文主要是介绍使用工厂方法模式实现各种不同分润规则，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

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github: https://github.com/kco1989/kco
代码已经全部托管github有需要的同学自行下载

引言

在上一篇文章中使用简单工厂编写不同的分润规则遗留着一个问题,那就是如果要新增分润规则,则需要修改原来的类.也就是代码没有完全解耦.
因此在这一篇中,我将分润规则的设计改为抽象工厂模式来编写.以解决上次遗留的问题.

改写示例

分润规则接口类

该类与上一篇是一样的.

public interface ProfitRole {double getProfit(double money);
}

分润规则抽象工厂类

public abstract class ProfitRoleFactory {public static ProfitRole createProfitRole(String profitTypeName, String expression){ProfitType profitType = ProfitType.getProfitType(profitTypeName);Matcher matcher = profitType.getPattern().matcher(expression);if (!matcher.matches()){throw new RuntimeException("分润表示时不符合" + profitType.getName() + "的规则.");}return profitType.getFactory().newProfitRole(profitType, matcher, expression);}protected abstract ProfitRole newProfitRole(ProfitType profitType, Matcher matcher, String expression);}

该类主要提供一个统一的接口ProfitRoleFactory.createProfitRole创建分润规则实现类
每一个分润规则实现类对应一个分润规则工厂类,由分润规则工厂类来创建出分润规则对象
再由分润规则对象实现具体的分润细节

分润规则类型

上一篇使用到的枚举类型.但是java不支持动态增加枚举成员.所以如果这一篇还是使用枚举类型的话,则在增加新的分润规则时难免需要修改该枚举类型.
因此,这一篇不是枚举类型.

public class ProfitType {// 非捕捉匹配正实数public static final String number = "(?:(?:[1-9]+\\d*)|(?:\\d))(?:\\.\\d+)?";// 捕捉匹配正实数public static final String realNumber = "(" + number + ")";// 捕捉匹配百分比public static final String rateNumber = realNumber + "%";// 分润规则mapprivate static final Map<String, ProfitType> profitTypeMap = new HashMap<>();static {ProfitType.registerProfitRole("FIXED_RATE","^"+ ProfitType.rateNumber +"$",new FixedRateRoleFactory(),"每笔收益率为0.1%则填写代理商收益0.1%;");ProfitType.registerProfitRole("FIXED_INCOME","^" + ProfitType.realNumber + "$",new FixedIncomeRoleFactory(),"每笔固定收益1元，则填写代理商收益1.00");ProfitType.registerProfitRole("FIXED_RATE_AND_FIXED_INCOME","^"+ ProfitType.rateNumber  + "\\+" + ProfitType.realNumber + "$",new FixedRateAndFixedIncomeRoleFactory(),"每笔收益率为0.1%加上固定收益1元，则填写代理商收益0.1%+1.00");ProfitType.registerProfitRole("FIXED_RATE_AND_UPPER_LIMIT","^"+ ProfitType.realNumber + "~" + ProfitType.rateNumber + "~" + ProfitType.realNumber  + "$",new FixedRateAndUpperLimitRoleFactory(),"每笔收益率为0.1%，封顶3元，保底1元则填写代理商收益1.00~0.1%~3.00;");ProfitType.registerProfitRole("GRADIENT_RATE","^"+ ProfitType.rateNumber+"(<"+ ProfitType.realNumber+"<"+ ProfitType.rateNumber+")+$",new GradientRateRoleFactory(),"梯度分润 例如 0.1%<10000<0.2%<20000<0.3%<30000<0.5%");}private String name;private String expression;private String description;private ProfitRoleFactory factory;public ProfitType(String name, String expression, ProfitRoleFactory factory, String description) {this.name = name;this.expression = expression;this.factory = factory;this.description = description;}public static Pattern getNumberPattern() {return Pattern.compile(number);}public String getName() {return name;}public Pattern getPattern(){return Pattern.compile(this.expression);}/*** 注册分润规则类型*/public static void registerProfitRole(String name, String profitRoleExpression,ProfitRoleFactory factory, String description){if (profitTypeMap.containsKey(name)){throw new RuntimeException("该"+name+"分润规则已经存在");}profitTypeMap.put(name, new ProfitType(name, profitRoleExpression, factory, description));}public ProfitRoleFactory getFactory() {return factory;}public String getDescription() {return description;}/*** 根据分润规则名字获取分润规则类型*/public static ProfitType getProfitType(String name){return profitTypeMap.get(name);}public static String getProfitTypeInfo(){StringBuilder sb = new StringBuilder();for (Map.Entry<String, ProfitType> entry : profitTypeMap.entrySet()){sb.append(entry.getKey() + " --> " + entry.getValue().getDescription() + "\n");}return sb.toString();}
}

ProfitType.profitTypeMap 存放分润类型名称和分润类型的key-value值
ProfitType.registerProfitRole 提供一个注册分润类型的借口
ProfitType static域 默认增加上一篇提到的5种分润规则

分润规则工厂类和分润规则实现类

目前提供五种分润规则:
1. 每笔固定收益1元，则填写代理商收益1.00
2. 每笔收益率为0.1%则填写代理商收益0.1%
3. 每笔收益率为0.1%加上固定收益1元，则填写代理商收益0.1%+1.00
4. 每笔收益率为0.1%，封顶3元，保底1元则填写代理商收益1.00~0.1%~3.00
5. 梯度分润例如 0.1%<10000<0.2%<20000<0.3%<30000<0.5%
- 少于10000 按照 0.1% 分润
- 少于20000 按照 0.2% 分润
- 少于30000 按照 0.3% 分润
- 多于30000 按照 0.5% 分润

分别对应于分润规则工厂类 -> 分润规则实现类:

FixedIncomeRoleFactory -> FixedIncomeRole
FixedRateRoleFactory -> FixedRateRole
FixedRateAndFixedIncomeRoleFactory -> FixedRateAndFixedIncomeRole
FixedRateAndUpperLimitRoleFactory -> FixedRateAndUpperLimitRole
GradientRateRoleFactory -> GradientRateRole

实现新的分润规则

如果需要实现新的分润规则,则分别编写一个分润规则工厂类和分润规则实现类,使其实分别继承(/实现)ProfitRoleFactory和ProfitRole,然后再调用ProfitType.registerProfitRole注册一下新的分润规则就万事大吉了.不需要修改原有的代码.也就是实现了完全解耦.

测试类

public class TestProfitRole2 {private static final List<Double> testDate = Arrays.asList(100.0,200.0,300.0,400.0,700.0,1000.0,2000.0,3000.0,7000.0,10000.0, 20000.0, 30000.0, 70000.0);@Testpublic void test(){String profitTypeInfo = ProfitType.getProfitTypeInfo();System.out.println(profitTypeInfo);}@Testpublic void testFixedIncome(){for (double data : testDate){ProfitRole fixedIncome = ProfitRoleFactory.createProfitRole("FIXED_INCOME", "1.00");double profit = fixedIncome.getProfit(data);Assert.assertEquals(1.00, profit, 0.00001);}}@Testpublic void testFixedRate(){for (double data : testDate){ProfitRole fixedRate = ProfitRoleFactory.createProfitRole("FIXED_RATE", "0.1%");double profit = fixedRate.getProfit(data);Assert.assertEquals(data * 0.1 * 0.01, profit, 0.00001);}}@Testpublic void testFixedRateAndFixedIncome(){for (double data : testDate){ProfitRole profitRole = ProfitRoleFactory.createProfitRole("FIXED_RATE_AND_FIXED_INCOME", "0.63%+3.00");double profit = profitRole.getProfit(data);Assert.assertEquals(data * 0.63 * 0.01 + 3.0, profit, 0.00001);}}@Testpublic void testFixedRateAndUpperLimit(){for (double data : testDate){ProfitRole profitRole = ProfitRoleFactory.createProfitRole("FIXED_RATE_AND_UPPER_LIMIT", "1.00~0.1%~3.00");double profit = profitRole.getProfit(data);double actual = data * 0.1 * 0.01;if (actual < 1.0){actual = 1.0;}if (actual > 3.0){actual = 3.0;}Assert.assertEquals(actual, profit, 0.00001);}}@Testpublic void testGradientRate(){for (double data : testDate){ProfitRole profitRole = ProfitRoleFactory.createProfitRole("GRADIENT_RATE", "0.1%<1000<0.2%<5000<0.3%<15000<0.5%");double profit = profitRole.getProfit(data);if (data < 1000){Assert.assertEquals(data * 0.01 * 0.1, profit, 0.00001);}else if (data < 5000){Assert.assertEquals(data * 0.01 * 0.2, profit, 0.00001);}else if(data < 15000){Assert.assertEquals(data * 0.01 * 0.3, profit, 0.00001);}else{Assert.assertEquals(data * 0.01 * 0.5, profit, 0.00001);}}}
}