【三十四】springboot+easyRule初识规则引擎

小z666

发布于 2024-09-02 08:08:11

1350

发布于 2024-09-02 08:08:11

文章被收录于专栏：java

代码场景：厂里有几个员工，现在厂长颁布了新的厂规关于薪资发放，如下：
1、加班时长超过80小时的，一个小时10块钱；不满80小时的，不算加班。
2、上班打卡迟到3次以下的不扣钱，3次以上的一次扣100。

针对如上需求，是不是就可以通过写if-if判断来处理，但是如果规则变化呢，老板想只要迟到1次就扣1000，或者只要加班就100块钱一个小时呢，是不是只有改代码升级。本章针对这个问题，通过规则引擎实现这个场景，实现规则配置化。

一、准备工作

1、表

2、依赖

<dependency>
            <groupId>org.jeasy</groupId>
            <artifactId>easy-rules-core</artifactId>
            <version>4.1.0</version>
        </dependency>

        <dependency>
            <groupId>org.jeasy</groupId>
            <artifactId>easy-rules-mvel</artifactId>
            <version>4.1.0</version>
        </dependency>

        <dependency>
            <groupId>org.jeasy</groupId>
            <artifactId>easy-rules-spel</artifactId>
            <version>4.1.0</version>
        </dependency>

        <dependency>
            <groupId>org.jeasy</groupId>
            <artifactId>easy-rules-jexl</artifactId>
            <version>4.1.0</version>
        </dependency>

二、注解方式实现

1、编写目的场景的规则

@Rule(name = "无效加班", description = "加班费的结算", priority = 1)
public class Rule1 {

    @Condition
    public boolean when(@Fact("time") double time) {
        return time<=80;
    }

    @Action
    public void then(@Fact("reason") StringBuffer reason) {
        reason.append("加班少于80小时，不发加班费;");
    }

}

@Rule(name = "有效加班", description = "加班费的结算", priority = 2)
public class Rule2 {

    @Condition
    public boolean when(@Fact("time") double time) {
        return time > 80;
    }

    @Action
    public void then(@Fact("time") double time,@Fact("reason") StringBuffer reason,@Fact("money") AtomicDouble money) {
        money.set(money.get()+10*(time-80));
        reason.append("加班费:").append(10*(time-80)).append(";");
    }

}

@Rule(name = "迟到警告", description = "迟到的惩罚", priority = 3)
public class Rule3 {

    @Condition
    public boolean when(@Fact("count") int count) {
        return count<=3;
    }

    @Action
    public void then(@Fact("count") int count, @Fact("money") AtomicDouble money, @Fact("reason") StringBuffer reason) {
        reason.append("迟到小于3次，暂时不扣钱;");
    }

}

@Rule(name = "迟到扣钱", description = "迟到的惩罚", priority = 3)
public class Rule4 {

    @Condition
    public boolean when(@Fact("count") int count) {
        return count>3;
    }

    @Action
    public void then(@Fact("count") int count, @Fact("money") AtomicDouble money, @Fact("reason") StringBuffer reason) {
        money.set(money.get() - (count-3)*100);
        reason.append("迟到大于3次，扣钱:").append((count - 3) * 100).append(";");
    }

}

@Rule标识该类为规则类
@Condition标识该方法为条件（一个rule类只能有一个）
@Action标识该方法为条件满足为true后的执行方法
@Fact代表事实，标识入参，可以通过Fact的key值获取值
priority标识该rule的执行顺序

2、编写接口

@Slf4j
@Api(tags = "牛马管理接口")
@RestController
@RequestMapping("/staffController")
@AllArgsConstructor
public class StaffController {

    private final StaffMapper staffMapper;
    
    @ApiOperation(value = "计算工资")
    @PostMapping("/getSalary")
    public BaseResponse<Integer> getSalary() {
        // 初始化规则引擎
        RulesEngineParameters parameters = new RulesEngineParameters().skipOnFirstAppliedRule(false);
        DefaultRulesEngine engine = new DefaultRulesEngine(parameters);
        engine.registerRuleListener(new MyRuleListener());

        // 注册规则进入引擎
        Rules rules = new Rules();
        rules.register(new Rule1());
        rules.register(new Rule2());
        rules.register(new Rule3());
        rules.register(new Rule4());
        //UnitRuleGroup unitRuleGroup = new UnitRuleGroup("myUnitRuleGroup", "myUnitRuleGroup");
        //unitRuleGroup.addRule(new Rule1());
        //unitRuleGroup.addRule(new Rule2());
        //unitRuleGroup.addRule(new Rule3());
        //unitRuleGroup.addRule(new Rule4());
        //rules.register(unitRuleGroup);

        List<Staff> list = staffMapper.selectList(new QueryWrapper<>());

        for (Staff staff : list) {
            AtomicDouble money = new AtomicDouble((Double.parseDouble(staff.getMoney())));
            double beforeMoney = money.get();
            StringBuffer reason = new StringBuffer();
            Facts facts = new Facts();
            facts.put("time", Double.parseDouble(staff.getTime()));
            facts.put("count", staff.getCount());
            facts.put("money", money);
            facts.put("reason", reason);
            engine.fire(rules, facts);

            Staff staffNew = staffMapper.selectById(staff.getId());
            staffNew.setFinalMoney(facts.get("money").toString());
            staffNew.setDetail(reason.toString());
            staffMapper.updateById(staffNew);

        }

        return RespGenerator.returnOK("成功");
    }

}

3、测试

根据结果可以看到数据正确。

现在假设我们厂长更改了需求：现在只要迟到超过3次，都没有加班费。

如上代码可以根据实际情况改造一下，当有需求所有规则要么全部执行，要么全部不执行时（只要有一个不满足就全部跳过执行），可以选用另一种方式UnitRuleGroup，改造如下：

@ApiOperation(value = "计算工资")
    @PostMapping("/getSalary")
    public BaseResponse<Integer> getSalary() {
        // 初始化规则引擎
        RulesEngineParameters parameters = new RulesEngineParameters().skipOnFirstAppliedRule(false);
        DefaultRulesEngine engine = new DefaultRulesEngine(parameters);
        engine.registerRuleListener(new MyRuleListener());

        // 注册规则进入引擎
        Rules rules = new Rules();
        //rules.register(new Rule1());
        //rules.register(new Rule2());
        //rules.register(new Rule3());
        //rules.register(new Rule4());
        UnitRuleGroup unitRuleGroup = new UnitRuleGroup("myUnitRuleGroup", "myUnitRuleGroup");
        //unitRuleGroup.addRule(new Rule1());
        unitRuleGroup.addRule(new Rule2());
        unitRuleGroup.addRule(new Rule3());
        //unitRuleGroup.addRule(new Rule4());
        rules.register(unitRuleGroup);

        List<Staff> list = staffMapper.selectList(new QueryWrapper<>());

        for (Staff staff : list) {
            AtomicDouble money = new AtomicDouble((Double.parseDouble(staff.getMoney())));
            double beforeMoney = money.get();
            StringBuffer reason = new StringBuffer();
            Facts facts = new Facts();
            facts.put("time", Double.parseDouble(staff.getTime()));
            facts.put("count", staff.getCount());
            facts.put("money", money);
            facts.put("reason", reason);
            engine.fire(rules, facts);

            Staff staffNew = staffMapper.selectById(staff.getId());
            staffNew.setFinalMoney(facts.get("money").toString());
            staffNew.setDetail(reason.toString());
            staffMapper.updateById(staffNew);

        }

        return RespGenerator.returnOK("成功");
    }

结果如下：

可以看到赵四加班了一个小时也没有加班费了。

三、yml配置方式实现

1、增加配置文件

---
name: '无效加班'
description: '加班费的结算'
priority: 1
condition: "time<=80"
actions:
  - "reason.append('加班少于80小时，不发加班费;');"
---
name: '有效加班'
description: '加班费的结算'
priority: 2
condition: "time>80"
actions:
  - "money.set(money.get()+10*(time-80));reason.append('加班费:').append(10*(time-80)).append(';');"
---
name: '迟到警告'
description: '迟到的惩罚'
priority: 1
condition: "count<=3"
actions:
  - "reason.append('迟到小于3次，暂时不扣钱;');"
---
name: '迟到扣钱'
description: '迟到的惩罚'
priority: 2
condition: "count>3"
actions:
  - "money.set(money.get() - (count-3)*1000);reason.append('迟到大于3次，扣钱:').append((count - 3) * 1000).append(';');"

每个rule之间通过---进行分割，可以在condition和actions下写java代码。

2、改造接口

@ApiOperation(value = "计算工资")
    @PostMapping("/getSalary")
    public BaseResponse getSalary() throws Exception {
        // 初始化规则引擎
        RulesEngineParameters parameters = new RulesEngineParameters().skipOnFirstAppliedRule(false);
        DefaultRulesEngine engine = new DefaultRulesEngine(parameters);
        engine.registerRuleListener(new MyRuleListener());

        // 注册规则进入引擎
        MVELRuleFactory ruleFactory = new MVELRuleFactory(new YamlRuleDefinitionReader());
        Rules rules = ruleFactory.createRules(new BufferedReader(new InputStreamReader(
                Objects.requireNonNull(this.getClass().getClassLoader().getResourceAsStream("rules.yml")))));

        List<Staff> list = staffMapper.selectList(new QueryWrapper<>());

        for (Staff staff : list) {
            AtomicDouble money = new AtomicDouble((Double.parseDouble(staff.getMoney())));
            double beforeMoney = money.get();
            StringBuffer reason = new StringBuffer();
            Facts facts = new Facts();
            facts.put("time", Double.parseDouble(staff.getTime()));
            facts.put("count", staff.getCount());
            facts.put("money", money);
            facts.put("reason", reason);
            engine.fire(rules, facts);

            Staff staffNew = staffMapper.selectById(staff.getId());
            staffNew.setFinalMoney(facts.get("money").toString());
            staffNew.setDetail(reason.toString());

            staffMapper.updateById(staffNew);

        }

        return RespGenerator.returnOK("成功");
    }

假设当我们调整加班费时（1块钱一个小时），修改配置即可。

name: '有效加班'
description: '加班费的结算'
priority: 2
condition: "time>80"
actions:
  - "money.set(money.get()+1*(time-80));reason.append('加班费:').append(1*(time-80)).append(';');"