场景

之前介绍了Easy Rules作为Java一款轻量级的规则引擎，使得研发更加注重于纯业务开发，提高开发效率。

这一篇，主要是围绕，规则配置数据，外置于数据库Mysql的实现。

思路

1、Mysql存储

新建表t_biz_rule、t_biz_rule_compose分别存储规则定义、规则组合定义

2、构建Rules

• Mysql中的Rule、RuleCompose转换成RuleDefinition对象
• 定义Rules注册工具类Helper，为每个RuleCompose注册

3、定义Facts以及RulesEngine

实现

1、Mysql实现规则配置的CRUD

定义对象BizRule

@Data
@Accessors(chain = true)
public class BizRule implements Serializable {

  /**
   * 主键ID
   */
  private Long id;

  /**
   * 规则组
   */
  private String groupCode;

  /**
   * 规则名称
   */
  private String name;

  /**
   * 规则描述
   */
  private String description;

  /**
   * 规则权重
   */
  private int priority;

  /**
   * 规则组合类型(compositeRuleType)
   * {@link CompositeRuleTypeEnum}
   */
  private Integer compositeType;

  /**
   * 状态 0有效-1无效
   */
  private Integer status;

  /**
   * 创建时间
   */
  private Date createTime;

  /**
   * 变更时间
   */
  private Date updateTime;
}

定义对象BizRuleCompose

@Data
@Accessors(chain = true)
public class BizRuleCompose implements Serializable {

  /**
   * 主键ID
   */
  private Long id;

  /**
   * 规则ID
   */
  private Long ruleId;

  /**
   * 规则名称
   */
  private String name;

  /**
   * 规则描述
   */
  private String description;

  /**
   * 规则权重
   */
  private int priority;

  /**
   * 规则条件（Java代码）
   */
  private String condition;

  /**
   * 执行操作
   */
  private String actions;

  /**
   * 状态 0有效-1无效
   */
  private Integer status;
  /**
   * 创建时间
   */
  private Date createTime;
}

定义CRUD参数Bo

@Data
public class BizRuleBo implements Serializable {

  /**
   * 名称
   */
  @NotNull(message = "请输入规则名称")
  @Size(min = 2, max = 50, message = "规则名称2-50个字符")
  private String name;

  /**
   * 描述
   */
  @NotNull(message = "请输入规则描述")
  @Size(min = 2, max = 20, message = "规则名称2-10个字符")
  private String description;

  /**
   * 规则组
   */
  @NotNull(message = "请定义规则组")
  @Size(min = 2, max = 10, message = "规则名称2-10个字符")
  private String groupCode;

  /**
   * 权限
   */
  private int priority;

  /**
   * 组合类型
   */
  private Integer compositeType;

  /**
   * 组合规则
   */
  private List composingRules;
}

API实现

@RestController
@RequestMapping("biz_rule")
@AllArgsConstructor
@Validated
public class BizRuleController {

  private BizRuleService bizRuleService;

  @AuthIgnore
  @PostMapping("/add")
  @OperationLog(value = "业务规则新建", type = LogOperationEnum.ADD)
  public ResultVo add(@RequestBody @Valid BizRuleBo bo) {
    return ResultVo.success(bizRuleService.addRule(bo));
  }
}

POST请求结果

规则配置新增操作

2、通过Heler工具类构建Rules对象

定义BizRuleHelper

public class BizRuleHelper extends AbstractRuleFactory {

  private final ParserContext parserContext;

  public BizRuleHelper(ParserContext parserContext) {
    this.parserContext = parserContext;
  }


  /**
   * 创建规则
   * @param ruleDefinitions 规则定义
   * @return 结果
   */
  public Rules createRules(List ruleDefinitions) {
    Rules rules = new Rules();
    ruleDefinitions.forEach(ruleDefinition -> rules.register(createRule(ruleDefinition)));
    return rules;
  }

  @Override
  public Rule createSimpleRule(RuleDefinition ruleDefinition) {
    MVELRule mvelRule = new MVELRule(parserContext)
        .name(ruleDefinition.getName())
        .description(ruleDefinition.getDescription())
        .priority(ruleDefinition.getPriority())
        .when(ruleDefinition.getCondition());
    for (String action : ruleDefinition.getActions()) {
      mvelRule.then(action);
    }
    return mvelRule;
  }
}

定义RulesConfig

@Component
@AllArgsConstructor
public class BizRulesConfig {

  private BizRuleService bizRuleService;

  static String group_code = "order_rule";

  /**
   * 构建rules配置
   */
  public Rules fetchConfigRules() {
    //JSON 表达式
    BizRuleHelper bizRuleHelper = new BizRuleHelper(new ParserContext());
    return bizRuleHelper.createRules(bizRuleService.ruleDefinitions(group_code));
  }
}

3、API代码

@AuthIgnore
  @OperationLog(value = "easy rules DB测试")
  @PostMapping("/db")
  @SneakyThrows
  public ResultVo<?> dbTest(@RequestBody BizOrder order) {
    //定义数据
    Facts facts = new Facts();
    facts.put("param", order);
    facts.put("OrderService",OrderService.class);
    //读取配置
    Rules rules = bizRulesConfig.fetchConfigRules();
    //引擎配置
    RulesEngine rulesEngine = new DefaultRulesEngine();
    rulesEngine.fire(rules, facts);
    return ResultVo.success();
  }

4、场景模拟

和前一篇类似，模拟商品1，是打折商品，原价200，折扣7折，计算最后价格。

模拟请求参数

代码逻辑处理

我们可以看出，通过调用统一接口/order/db，最终还是执行了折扣的业务逻辑。