前言介紹

在上一章節(jié)介紹了領(lǐng)域驅(qū)動(dòng)設(shè)計(jì)的基本概念以及按照領(lǐng)域驅(qū)動(dòng)設(shè)計(jì)的思想進(jìn)行代碼分層，但是僅僅只是從一個(gè)簡(jiǎn)單的分層結(jié)構(gòu)上依然沒(méi)法理解DDD以及如何去開(kāi)發(fā)這樣的微服務(wù)。另外往往按照這樣分層后依然感覺(jué)和MVC也沒(méi)有什么差別，也沒(méi)有感受到帶來(lái)什么非常大的好處。那么問(wèn)題出在哪呢？我個(gè)人覺(jué)得DDD學(xué)起來(lái)更像是一套指導(dǎo)思想，不斷的將學(xué)習(xí)者引入到領(lǐng)域觸發(fā)的思維中去，而這恰恰也是最難學(xué)習(xí)的地方。時(shí)而感覺(jué)會(huì)了，而實(shí)際開(kāi)發(fā)中又不對(duì)，本來(lái)已經(jīng)拆解清晰了，但怎么又那么像MVC了。甚至懷疑自己，我在干嘛？

【資料圖】

無(wú)論是DDD、MVC，他們更像是家里三居或者四局的格局，每一種格局方式都是為了更好的實(shí)現(xiàn)對(duì)應(yīng)架構(gòu)下的設(shè)計(jì)思想。但，不是說(shuō)給你一個(gè)通用的架構(gòu)模式，你就能開(kāi)發(fā)出干凈(高內(nèi)聚)、整潔(低耦合)、漂亮(模塊化)的代碼。這就像是你家住三居、他家也住三居，但是你們屋子的舒適情況就一樣嗎？｛再有，你家里會(huì)把廁所安在廚房嗎？但你的代碼是否這么干過(guò)，不合理的擺放導(dǎo)致重構(gòu)延期。｝

另外DDD之所以看著簡(jiǎn)單但又不那么好落地，個(gè)人認(rèn)為很重要就是領(lǐng)域思想，DDD只是指導(dǎo)但是不能把互聯(lián)網(wǎng)天下每一個(gè)業(yè)務(wù)行為開(kāi)發(fā)都拿出來(lái)舉例子給你看，每個(gè)領(lǐng)域需要設(shè)計(jì)。所以需要一些領(lǐng)域?qū)＜遥a(chǎn)品+架構(gòu)+不是杠精的程序猿｝來(lái)討論梳理，將業(yè)務(wù)形態(tài)設(shè)計(jì)出合理的架構(gòu)&代碼。

案例目標(biāo)

本案例通過(guò)一個(gè)商品下單規(guī)則的場(chǎng)景來(lái)進(jìn)行演示DDD；

假設(shè)產(chǎn)品需求業(yè)務(wù)運(yùn)行人員可以對(duì)不同的商品配置一些規(guī)則，這些規(guī)則可以滿(mǎn)足不同用戶(hù)類(lèi)型可以下單不同商品。另外一些行為規(guī)則是會(huì)隨著業(yè)務(wù)發(fā)展而增加或者變動(dòng)的，所以不能寫(xiě)死｛寫(xiě)死太嚇人了｝。數(shù)據(jù)庫(kù)的PO類(lèi)不應(yīng)該被外部服務(wù)調(diào)用，這也是必須的。如果你開(kāi)發(fā)過(guò)很多系統(tǒng)，那么可能已經(jīng)吃過(guò)虧并意識(shí)到這個(gè)問(wèn)題。按照DDD思想我們嘗試需要設(shè)計(jì)一個(gè)規(guī)則引擎的服務(wù)，通過(guò)給外部提供非常簡(jiǎn)單的接口（application）來(lái)獲取最終結(jié)果。通過(guò)這樣的案例可以很容易的感受到目前的四層架構(gòu)確實(shí)在實(shí)現(xiàn)DDD思想上有很多的幫助。

如圖；DDD分層結(jié)構(gòu) | 指導(dǎo)設(shè)計(jì)架構(gòu)

bugstack蟲(chóng)洞棧 & 分層結(jié)構(gòu)

DDD思想 · 開(kāi)發(fā)設(shè)計(jì)

通過(guò)領(lǐng)域驅(qū)動(dòng)設(shè)計(jì)的思想，從領(lǐng)域知識(shí)中提取和劃分為一個(gè)一個(gè)的子領(lǐng)域（核心子域，通用子域，支撐子域），并在子領(lǐng)域上建立模型。那么在技術(shù)實(shí)現(xiàn)上就需要去支撐這種建模，以使我們的代碼模塊獨(dú)立、免污染、易于擴(kuò)展。

在上面我們提到需要開(kāi)發(fā)一個(gè)可擴(kuò)展使用的規(guī)則樹(shù)，那么如果只是單純的一次性需求，最快的方式是if語(yǔ)句就搞定了。但是為了使這個(gè)領(lǐng)域服務(wù)具備良好的使用和擴(kuò)展性，我們需要做些拆分，那么如下；

你是否想過(guò)系統(tǒng)在過(guò)濾過(guò)則的時(shí)候其實(shí)就像執(zhí)行一棵二叉樹(shù)一樣非左即右側(cè)，每一條線(xiàn)上都有著執(zhí)行條件，通過(guò)判斷來(lái)達(dá)到最終的結(jié)果。按照樹(shù)形結(jié)構(gòu)我們將定義出來(lái)四個(gè)類(lèi)；樹(shù)、節(jié)點(diǎn)、果實(shí)、指向線(xiàn)(From-To)，用于描述我們的規(guī)則行為。再此基礎(chǔ)上需要實(shí)現(xiàn)一個(gè)邏輯定義與規(guī)則樹(shù)執(zhí)行引擎，通過(guò)統(tǒng)一的引擎服務(wù)來(lái)執(zhí)行我們每次配置好的規(guī)則樹(shù)。

如圖；領(lǐng)域開(kāi)發(fā)設(shè)計(jì)服務(wù)

bugstack蟲(chóng)洞棧 & 領(lǐng)域開(kāi)發(fā)設(shè)計(jì)服務(wù)

工程模型

itstack-demo-ddd-02└── src    ├── main    │   ├── java    │   │   └── org.itstack.demo    │   │       ├── application    │   │       │ ├── MallRuleService.java     │   │       │ └── MallTreeService.java     │   │       ├── domain    │   │       │ ├── rule    │   │       │ │   ├── model    │   │       │ │   │   ├── aggregates    │   │       │ │   │   │   └── UserRichInfo.java     │   │       │ │   │   └── vo    │   │       │ │   │       ├── DecisionMatter.java    │   │       │ │   │       ├── EngineResult.java    │   │       │ │   │       ├── TreeNodeInfo.java    │   │       │ │   │       ├── TreeNodeLineInfo.java     │   │       │ │   │       └── UserSchool.java     │   │       │ │   ├── repository    │   │       │ │   │   └── IRuleRepository.java     │   │       │ │   └── service    │   │       │ │       ├── engine    │   │       │ │       │   ├── impl     │   │       │ │       │   └── EngineFilter.java     │   │       │ │       ├── logic    │   │       │ │       │   ├── impl     │   │       │ │       │   └── LogicFilter.java     │   │       │ │       └── MallRuleServiceImpl.java     │   │       │ └── tree    │   │       │     ├── model    │   │       │     │   ├── aggregates    │   │       │     │   │   └── TreeCollect.java     │   │       │     │   └── vo    │   │       │     │       ├── TreeInfo.java     │   │       │     │       └── TreeRulePoint.java     │   │       │     ├── repository    │   │       │     │   └── ITreeRepository.java     │   │       │     └── service    │   │       │         └── MallTreeServiceImpl.java     │   │       ├── infrastructure    │   │       │ ├── common    │   │       │ │   └── Constants.java    │   │       │ ├── dao    │   │       │ │   ├── RuleTreeDao.java    │   │       │ │   ├── RuleTreeNodeDao.java     │   │       │ │   └── RuleTreeNodeLineDao.java     │   │       │ ├── po    │   │       │ │   ├── RuleTree.java    │   │       │ │   ├── RuleTreeConfig.java    │   │       │ │   ├── RuleTreeNode.java     │   │       │ │   └── RuleTreeNodeLine.java      │   │       │ ├── repository    │   │       │ │   ├── cache    │   │       │ │   │   └── RuleCacheRepository.java    │   │       │ │   ├── mysql    │   │       │ │   │   ├── RuleMysqlRepository.java     │   │       │ │   │   └── TreeMysqlRepository.java    │   │       │ │   ├── RuleRepository.java     │   │       │ │   └── TreeRepository.java     │   │       │ └── util    │   │       │     └── CacheUtil.java    │   │       ├── interfaces    │   │       │ ├── dto    │   │       │ │ ├── DecisionMatterDTO.java    │   │       │ │ └── TreeDTO.java     │   │       │ └── DDDController.java    │   │       └── DDDApplication.java    │   └── resources     │       ├── mybatis    │       └── application.yml    └── test         └── java             └── org.itstack.demo.test                 └── ApiTest.java

application應(yīng)用層

application/MallRuleService.java | 應(yīng)用層定義接口服務(wù)，也可以適當(dāng)做簡(jiǎn)單包裝

/** * 商超規(guī)則過(guò)濾服務(wù)；提供規(guī)則樹(shù)決策功能 * 微信公眾號(hào)：bugstack蟲(chóng)洞棧 | 專(zhuān)注原創(chuàng)技術(shù)專(zhuān)題案例 * 論壇：http://bugstack.cn * Create by 付政委 on @2019 */public interface MallRuleService {    /**     * 決策服務(wù)     * @param matter 決策物料     * @return    EngineResult process(final DecisionMatter matter);}

domain領(lǐng)域?qū)?p>domain中有兩個(gè)領(lǐng)域服務(wù)；規(guī)則樹(shù)信息領(lǐng)域、規(guī)則執(zhí)行領(lǐng)域，通過(guò)合理的抽象化來(lái)實(shí)現(xiàn)高內(nèi)聚、低耦合的模塊化服務(wù)

domain/service/MallRuleServiceImpl.java | 領(lǐng)域?qū)又械膕ervice來(lái)實(shí)現(xiàn)應(yīng)用層接口

/** * 規(guī)則樹(shù)服務(wù)；提供規(guī)則規(guī)律功能 * * 1、rule包下只進(jìn)行規(guī)則決策領(lǐng)域的處理 * 2、封裝決策行為到領(lǐng)域模型中，外部只需要調(diào)用和處理結(jié)果即可 * 3、可以擴(kuò)展不同的決策引擎進(jìn)行統(tǒng)一管理 * * 微信公眾號(hào)：bugstack蟲(chóng)洞棧 | 專(zhuān)注原創(chuàng)技術(shù)專(zhuān)題案例 * 論壇：http://bugstack.cn * Create by 付政委 on @2019 */@Service("mallRuleService")public class MallRuleServiceImpl implements MallRuleService {    private Logger logger = LoggerFactory.getLogger(MallRuleServiceImpl.class);    @Resource(name = "ruleEngineHandle")    private EngineFilter ruleEngineHandle;    @Override    public EngineResult process(DecisionMatter matter){        try {            return ruleEngineHandle.process(matter);        } catch (Exception e) {            logger.error("決策引擎執(zhí)行失敗", e);            return new EngineResult(false);        }    }}

domain/service/logic/LogicFilter.java | 邏輯決策定義

/** * 微信公眾號(hào)：bugstack蟲(chóng)洞棧 | 專(zhuān)注原創(chuàng)技術(shù)專(zhuān)題案例 * 論壇：http://bugstack.cn * Create by 付政委 on @2019 */public interface LogicFilter {    /**     * 邏輯決策器     * @param matterValue          決策值     * @param treeNodeLineInfoList 決策節(jié)點(diǎn)     * @return    Long filter(String matterValue, List treeNodeLineInfoList);    /**     * 獲取決策值     *     * @param decisionMatter 決策物料     * @return    String matterValue(DecisionMatter decisionMatter);}

domain/service/engine/EngineFilter.java | 引擎執(zhí)行定義

/** * 微信公眾號(hào)：bugstack蟲(chóng)洞棧 | 專(zhuān)注原創(chuàng)技術(shù)專(zhuān)題案例 * 論壇：http://bugstack.cn * Create by 付政委 on @2019 */public interface EngineFilter {    EngineResult process(final DecisionMatter matter) throws Exception;}

infrastructure基礎(chǔ)層

1、實(shí)現(xiàn)領(lǐng)域?qū)觽}(cāng)儲(chǔ)定義 2、數(shù)據(jù)庫(kù)操作為非業(yè)務(wù)屬性的功能操作 3、在倉(cāng)儲(chǔ)實(shí)現(xiàn)層進(jìn)行組合裝配DAO&Redis&Cache等

infrastructure/repository/RuleRepository.java

/** * 微信公眾號(hào)：bugstack蟲(chóng)洞棧 | 專(zhuān)注原創(chuàng)技術(shù)專(zhuān)題案例 * 論壇：http://bugstack.cn * Create by 付政委 on @2019 */public interface EngineFilter {    EngineResult process(final DecisionMatter matter) throws Exception;}

interfaces接口層

1、包裝應(yīng)用接口對(duì)外提供api 2、外部傳輸對(duì)象采用DTO類(lèi)，主要為了避免內(nèi)部類(lèi)被污染｛不斷的迭代的需求會(huì)在類(lèi)中增加很多字段｝ 3、目前依然是提供的Http服務(wù)，如果提供的rpc服務(wù)，將需要對(duì)外提供可引用jar

interfaces/DDDController.java

** * 微信公眾號(hào)：bugstack蟲(chóng)洞棧 | 歡迎關(guān)注學(xué)習(xí)專(zhuān)題案例 * 論壇：http://bugstack.cn * Create by 付政委 on @2019 */@Controllerpublic class DDDController {    private Logger logger = LoggerFactory.getLogger(DDDController.class);    @Resource    private MallTreeService mallTreeService;    @Resource    private MallRuleService mallRuleService;    /**     * 測(cè)試接口：http://localhost:8080/api/tree/queryTreeSummaryInfo     * 請(qǐng)求參數(shù)：{"treeId":10001}     */    @RequestMapping(path = "/api/tree/queryTreeSummaryInfo", method = RequestMethod.POST)    @ResponseBody    public ResponseEntity queryTreeSummaryInfo(@RequestBody TreeDTO request) {        String reqStr = JSON.toJSONString(request);        try {            logger.info("查詢(xún)規(guī)則樹(shù)信息{}Begin req：{}", request.getTreeId(), reqStr);            TreeCollect treeCollect = mallTreeService.queryTreeSummaryInfo(request.getTreeId());            logger.info("查詢(xún)規(guī)則樹(shù)信息{}End res：{}", request.getTreeId(), JSON.toJSON(treeCollect));            return new ResponseEntity<>(treeCollect, HttpStatus.OK);        } catch (Exception e) {            logger.error("查詢(xún)規(guī)則樹(shù)信息{}Error req：{}", request.getTreeId(), reqStr, e);            return new ResponseEntity<>(e.getMessage(), HttpStatus.OK);        }    }    /**     * 測(cè)試接口：http://localhost:8080/api/tree/decisionRuleTree     * 請(qǐng)求參數(shù)：{"treeId":10001,"userId":"fuzhengwei","valMap":{"gender":"man","age":"25"}}     */    @RequestMapping(path = "/api/tree/decisionRuleTree", method = RequestMethod.POST)    @ResponseBody    public ResponseEntity decisionRuleTree(@RequestBody DecisionMatterDTO request) {        String reqStr = JSON.toJSONString(request);        try {            logger.info("規(guī)則樹(shù)行為信息決策{}Begin req：{}", request.getTreeId(), reqStr);            DecisionMatter decisionMatter = new DecisionMatter();            decisionMatter.setTreeId(request.getTreeId());            decisionMatter.setUserId(request.getUserId());            decisionMatter.setValMap(request.getValMap());            EngineResult engineResult = mallRuleService.process(decisionMatter);            logger.info("規(guī)則樹(shù)行為信息決策{}End res：{}", request.getTreeId(), JSON.toJSON(engineResult));            return new ResponseEntity<>(engineResult, HttpStatus.OK);        } catch (Exception e) {            logger.error("規(guī)則樹(shù)行為信息決策{}Error req：{}", request.getTreeId(), reqStr, e);            return new ResponseEntity<>(e.getMessage(), HttpStatus.OK);        }    }}

測(cè)試驗(yàn)證

規(guī)則樹(shù)結(jié)構(gòu){數(shù)據(jù)庫(kù)轉(zhuǎn)Json} | 可自行定義

{    "treeNodeMap": {        "1": {            "nodeType": 1,            "ruleDesc": "用戶(hù)性別[男/女]",            "ruleKey": "userGender",            "treeId": 10001,            "treeNodeId": 1,            "treeNodeLineInfoList": [                {                    "nodeIdFrom": 1,                    "nodeIdTo": 11,                    "ruleLimitType": 1,                    "ruleLimitValue": "man"                },                {                    "nodeIdFrom": 1,                    "nodeIdTo": 12,                    "ruleLimitType": 1,                    "ruleLimitValue": "woman"                }            ]        },        "11": {            "nodeType": 1,            "ruleDesc": "用戶(hù)年齡",            "ruleKey": "userAge",            "treeId": 10001,            "treeNodeId": 11,            "treeNodeLineInfoList": [                {                    "nodeIdFrom": 11,                    "nodeIdTo": 111,                    "ruleLimitType": 3,                    "ruleLimitValue": "25"                },                {                    "nodeIdFrom": 11,                    "nodeIdTo": 112,                    "ruleLimitType": 3,                    "ruleLimitValue": "25"                }            ]        },        "12": {            "nodeType": 1,            "ruleDesc": "用戶(hù)年齡",            "ruleKey": "userAge",            "treeId": 10001,            "treeNodeId": 12,            "treeNodeLineInfoList": [                {                    "nodeIdFrom": 12,                    "nodeIdTo": 121,                    "ruleLimitType": 3,                    "ruleLimitValue": "25"                },                {                    "nodeIdFrom": 12,                    "nodeIdTo": 122,                    "ruleLimitType": 3,                    "ruleLimitValue": "25"                }            ]        },        "111": {            "nodeType": 2,            "nodeValue": "果實(shí)A",            "treeId": 10001,            "treeNodeId": 111,            "treeNodeLineInfoList": [ ]        },        "112": {            "nodeType": 2,            "nodeValue": "果實(shí)B",            "treeId": 10001,            "treeNodeId": 112,            "treeNodeLineInfoList": [ ]        },        "121": {            "nodeType": 2,            "nodeValue": "果實(shí)C",            "treeId": 10001,            "treeNodeId": 121,            "treeNodeLineInfoList": [ ]        },        "122": {            "nodeType": 2,            "nodeValue": "果實(shí)D",            "treeId": 10001,            "treeNodeId": 122,            "treeNodeLineInfoList": [ ]        }    },    "treeRoot": {        "treeId": 10001,        "treeName": "購(gòu)物分類(lèi)規(guī)則樹(shù)",        "treeRootNodeId": 1    }}

通過(guò)postman調(diào)用 | raw => json

查詢(xún)規(guī)則樹(shù)信息測(cè)試接口：http://localhost:8080/api/tree/decisionRuleTree 請(qǐng)求參數(shù)：{"treeId":10001}

{    "treeInfo": {        "treeId": 10001,        "treeName": "購(gòu)物分類(lèi)規(guī)則樹(shù)",        "treeDesc": "用于分類(lèi)不同類(lèi)型用戶(hù)可購(gòu)物范圍",        "nodeCount": 7,        "lineCount": 6    },    "treeRulePointList": [        {            "ruleKey": "userGender",            "ruleDesc": "用戶(hù)性別[男/女]"        },        {            "ruleKey": "userAge",            "ruleDesc": "用戶(hù)年齡"        }    ]}

微信公眾號(hào)：bugstack蟲(chóng)洞棧 & 查詢(xún)規(guī)則樹(shù)信息

規(guī)則樹(shù)行為信息決策測(cè)試接口：http://localhost:8080/api/tree/decisionRuleTree 請(qǐng)求參數(shù)：{"treeId":10001}

{    "userId": "fuzhengwei",    "treeId": 10001,    "nodeId": 112,    "nodeValue": "果實(shí)B",    "success": true}

微信公眾號(hào)：bugstack蟲(chóng)洞棧 & 規(guī)則樹(shù)行為信息決策

.   ____          _            __ _ _ /\\ / ___"_ __ _ _(_)_ __  __ _ \ \ \ \( ( )\___ | "_ | "_| | "_ \/ _` | \ \ \ \ \\/  ___)| |_)| | | | | || (_| |  ) ) ) )  "  |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot ::        (v2.0.5.RELEASE)2019-10-19 18:22:05.672  INFO 13820 --- [           main] org.itstack.demo.DDDApplication          : Starting DDDApplication on fuzhengwei-PC with PID 13820 (E:\itstack\itstack.org\itstack-demo-ddd-02\target\classes started by fuzhengwei in E:\itstack\itstack.org\itstack-demo-ddd-02)2019-10-19 18:22:05.675  INFO 13820 --- [           main] org.itstack.demo.DDDApplication          : No active profile set, falling back to default profiles: default2019-10-19 18:22:05.952  INFO 13820 --- [           main] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@3c4297f: startup date [Sat Oct 19 18:22:05 CST 2019]; root of context hierarchy2019-10-19 18:22:07.756  INFO 13820 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)2019-10-19 18:22:07.870  INFO 13820 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]2019-10-19 18:22:07.870  INFO 13820 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.342019-10-19 18:22:07.896  INFO 13820 --- [ost-startStop-1] o.a.catalina.core.AprLifecycleListener   : The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [D:\Program Files Java\Java\jdk1.8.0_162\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:\ProgramData\Oracle\Java\javapath;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;D:\Program Files Java\SlikSvn\bin;D:\Program Files Java\MySQL Server 5.1\bin;D:\Program Files Java\TortoiseGit\bin;D:\Program Files\nodejs\;D:\Program Files Java\Java\jdk1.6.0_24\bin;D:\Program Files Java\apache-maven-3.2.3\bin;C:\Users\fuzhengwei\AppData\Roaming\npm;D:\Program Files Java\Git\cmd;;.]2019-10-19 18:22:08.040  INFO 13820 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext2019-10-19 18:22:08.040  INFO 13820 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 2088 ms2019-10-19 18:22:08.102  INFO 13820 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Servlet dispatcherServlet mapped to [/]2019-10-19 18:22:08.126  INFO 13820 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: "characterEncodingFilter" to: [/*]2019-10-19 18:22:08.127  INFO 13820 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: "hiddenHttpMethodFilter" to: [/*]2019-10-19 18:22:08.127  INFO 13820 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: "httpPutFormContentFilter" to: [/*]2019-10-19 18:22:08.127  INFO 13820 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: "requestContextFilter" to: [/*]2019-10-19 18:22:09.118  INFO 13820 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]2019-10-19 18:22:09.383  INFO 13820 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@3c4297f: startup date [Sat Oct 19 18:22:05 CST 2019]; root of context hierarchy2019-10-19 18:22:10.261  INFO 13820 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/api/tree/decisionRuleTree],methods=[POST]}" onto public org.springframework.http.ResponseEntity org.itstack.demo.interfaces.DDDController.decisionRuleTree(org.itstack.demo.interfaces.dto.DecisionMatterDTO)2019-10-19 18:22:10.263  INFO 13820 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/api/tree/queryTreeSummaryInfo],methods=[POST]}" onto public org.springframework.http.ResponseEntity org.itstack.demo.interfaces.DDDController.queryTreeSummaryInfo(org.itstack.demo.interfaces.dto.TreeDTO)2019-10-19 18:22:10.272  INFO 13820 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity> org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.error(javax.servlet.http.HttpServletRequest)2019-10-19 18:22:10.274  INFO 13820 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)2019-10-19 18:22:10.309  INFO 13820 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]2019-10-19 18:22:10.309  INFO 13820 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]2019-10-19 18:22:16.272  INFO 13820 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup2019-10-19 18:22:16.273  INFO 13820 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Bean with name "dataSource" has been autodetected for JMX exposure2019-10-19 18:22:16.279  INFO 13820 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Located MBean "dataSource": registering with JMX server as MBean [com.zaxxer.hikari:name=dataSource,type=HikariDataSource]2019-10-19 18:22:16.375  INFO 13820 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ""2019-10-19 18:22:16.381  INFO 13820 --- [           main] org.itstack.demo.DDDApplication          : Started DDDApplication in 11.458 seconds (JVM running for 20.584)2019-10-19 18:22:31.336  INFO 13820 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring FrameworkServlet "dispatcherServlet"2019-10-19 18:22:31.336  INFO 13820 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet "dispatcherServlet": initialization started2019-10-19 18:22:31.372  INFO 13820 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet "dispatcherServlet": initialization completed in 36 ms2019-10-19 18:22:32.427  INFO 13820 --- [nio-8080-exec-1] o.itstack.demo.interfaces.DDDController  : 規(guī)則樹(shù)行為信息決策10001Begin req：{"treeId":10001,"userId":"fuzhengwei","valMap":{"gender":"man","age":"25"}}2019-10-19 18:22:32.508  INFO 13820 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Starting...2019-10-19 18:22:32.956  INFO 13820 --- [nio-8080-exec-1] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Start completed.2019-10-19 18:22:33.028  INFO 13820 --- [nio-8080-exec-1] o.i.d.d.rule.service.engine.EngineBase   : 樹(shù)引擎=>Test分類(lèi)規(guī)則樹(shù) userId：fuzhengwei treeId：10001 treeNode：11 ruleKey：userGender matterValue：man2019-10-19 18:22:33.028  INFO 13820 --- [nio-8080-exec-1] o.i.d.d.rule.service.engine.EngineBase   : 樹(shù)引擎=>Test分類(lèi)規(guī)則樹(shù) userId：fuzhengwei treeId：10001 treeNode：112 ruleKey：userAge matterValue：252019-10-19 18:22:33.039  INFO 13820 --- [nio-8080-exec-1] o.itstack.demo.interfaces.DDDController  : 規(guī)則樹(shù)行為信息決策10001End res：{"treeId":10001,"nodeValue":"果實(shí)B","success":true,"nodeId":112,"userId":"fuzhengwei"}2019-10-19 18:23:36.989  INFO 13820 --- [nio-8080-exec-5] o.itstack.demo.interfaces.DDDController  : 查詢(xún)規(guī)則樹(shù)信息10001Begin req：{"treeId":10001}2019-10-19 18:23:37.006  INFO 13820 --- [nio-8080-exec-5] o.itstack.demo.interfaces.DDDController  : 查詢(xún)規(guī)則樹(shù)信息10001End res：{"treeInfo":{"treeId":10001,"treeName":"購(gòu)物分類(lèi)規(guī)則樹(shù)","treeDesc":"用于分類(lèi)不同類(lèi)型用戶(hù)可購(gòu)物范圍","nodeCount":7,"lineCount":6},"treeRulePointList":[{"ruleDesc":"用戶(hù)性別[男/女]","ruleKey":"userGender"},{"ruleDesc":"用戶(hù)年齡","ruleKey":"userAge"}]}

綜上總結(jié)以上模擬購(gòu)物場(chǎng)景下的規(guī)則處理抽象為樹(shù)決策引擎，以達(dá)到獨(dú)立領(lǐng)域服務(wù)。另外決策服務(wù)可以使用drools，任何抽象并不一定永遠(yuǎn)使用，不要拘泥于一種形式。一些大型架構(gòu)設(shè)計(jì)往往不是換一個(gè)設(shè)計(jì)模型就能徹底提升效率，還是需要人員整體素質(zhì)，這是一個(gè)不斷培養(yǎng)的過(guò)程。領(lǐng)域驅(qū)動(dòng)設(shè)計(jì)的思想并不只是教會(huì)程序猿寫(xiě)代碼，也是非程序員以外的所有互聯(lián)網(wǎng)人員都適合學(xué)習(xí)的內(nèi)容。家里住的舒適不舒適，并不一定取決于三居或者四居，大部分還是依賴(lài)于怎么對(duì)格局的布置。事必躬親、親力親為的精益求精之路，終究會(huì)讓你設(shè)計(jì)出更加合理的代碼。

關(guān)鍵詞： 請(qǐng)求參數(shù) 分層結(jié)構(gòu) 也沒(méi)有什么