# 前置内容 0. 掌握策略模式 0. 掌握责任链模式 0. 掌握类继承、接口的实现 0. 掌握参数的传递与设置 0. [GitHub地址](https://github.com/xbhog/DesignPatternsStudy) **ps：【文章由来】** 公司项目中所用的合同签章处理流程，本人基于责任链上使用策略模式进行优化。 # 签章的处理流程 0. 合同文本初始化 0. 合同文本生成 0. 签章挡板是否开启 0. 合同签章发送mq 0. 合同签章流水更新 0. 合同上传文件服务器 0. 签章渠道选择 0. 签章渠道的实际调用执行的流程如下： ![](https://p3-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/602d860d432c4bb29b6fa174157724a8~tplv-k3u1fbpfcp-zoom-1.image) 整个结构类似于递归调用。每个节点中依赖上一个节点的输入以及下一个节点的输出，在中间过程可以实现每个节点的自定义操作，比较灵活。 # 流程实现 [GitHub地址](https://github.com/xbhog/DesignPatternsStudy) ## 项目结构 ``` DesignPatterns └── src └── main └── java └── com.xbhog.chainresponsibility ├── annotations │ └── ContractSign ├── channel │ ├── ContractSignChannelImpl.java │ └── ContractSignChannel ├── Config │ └── SignConfig ├── Enum │ └── ContractSignEnum ├── impl │ ├── ContractSignCompactInitImpl.java │ ├── ContractSignGenerateImpl.java │ ├── ContractSignMockImpl.java │ ├── ContractSignMqImpl.java │ ├── ContractSignSaveUploadImpl.java │ ├── ContractSignSerialImpl.java │ └── ContractSignTradeImpl.java ├── inter │ ├── Call │ ├── Chain │ ├── Interceptor │ └── Processor ├── pojo │ ├── ContractRequest.java │ └── ContractResponse.java ├── ContractCall ├── ContractChain └── ContractSignProcessor.java ``` ## 项目类图 ![](https://p3-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/5ed7a3958bad4fd79c9009192db5b36d~tplv-k3u1fbpfcp-zoom-1.image) ## 责任链+组合模式代码实现 ### 工程结构 ``` DesignPatterns └── src └── main └── java └── com.xbhog.chainresponsibility ├── channel │ ├── ContractSignChannelImpl.java │ └── ContractSignChannel ├── impl │ ├── ContractSignCompactInitImpl.java │ ├── ContractSignGenerateImpl.java │ ├── ContractSignMockImpl.java │ ├── ContractSignMqImpl.java │ ├── ContractSignSaveUploadImpl.java │ ├── ContractSignSerialImpl.java │ └── ContractSignTradeImpl.java ├── inter │ ├── Call │ ├── Chain │ ├── Interceptor │ └── Processor ├── pojo │ ├── ContractRequest.java │ └── ContractResponse.java ├── ContractCall ├── ContractChain └── ContractSignProcessor.java ``` ### 责任链中的对象定义 ``` //请求 @Data @NoArgsConstructor @AllArgsConstructor @Builder public class ContractRequest { private String name; private String age; private String status; } //响应 @Data @NoArgsConstructor @AllArgsConstructor @Builder public class ContractResponse { private String status; private String mas; } ``` 定义流程中的请求及响应类，方便处理每个责任链的请求、返回信息。 ### 责任链处理流程 ``` /** * @author xbhog * @describe: 责任链+组合实现合同签章 * @date 2023/7/11 */ @Slf4j @Component public class ContractSignProcessor implements Processor { @Resource(name = "contractSignCompactInitImpl") private Interceptor contractCompactInitImpl; ...... public ContractSignProcessor() { } @Override public ContractResponse process(T paramter) { //获取所有的监听器 List> interceptorList = new ArrayList<>(); interceptorList.add(contractCompactInitImpl); ...... //开始签章 log.info("签章开始"); return new ContractCall(paramter,interceptorList).exectue(); } } ``` 合同签章方法的**主流程调用接口(入口)** ，该类中注入所有的节点实现类(如`contractCompactInitImpl`)，通过编排实现责任链流程。在初始化节点之前，进行**节点的封装以及数据请求的处理**。例：`contractCompactInitImpl`-合同数据初始化节点 ``` /** * @author xbhog * @describe: 合同数据请求、节点的实例化及方法执行 * @date 2023/7/11 */ public class ContractCall implements Call { private final T originalRequest; private final List> interceptorList; public ContractCall(T originalRequest, List> interceptorList) { this.originalRequest = originalRequest; this.interceptorList = interceptorList; } @Override public T request() { return this.originalRequest; } @Override public ContractResponse exectue() { //实例化流程节点 ContractChain chain = new ContractChain(0,this.originalRequest,this.interceptorList); return chain.proceed(this.originalRequest); } } ``` 获取节点中的请求参数，实例化当前责任链节点(`contractCompactInitImpl`)，在执行节点中的`proceed`方法来获取当前节点的参数以及获取节点的信息。 ``` /** * @author xbhog * @describe: 合同节点 * @date 2023/7/11 */ @Slf4j public class ContractChain implements Chain { private final Integer index; private final T request; private final List> interceptors; public ContractChain(Integer index, T request, List> interceptors) { this.index = index; this.request = request; this.interceptors = interceptors; } @Override public T request() { return this.request; } @Override public ContractResponse proceed(T request) { //控制节点流程 if(this.index >= this.interceptors.size()){ throw new IllegalArgumentException("index越界"); } //下一个节点参数设置 Chain nextChain = new ContractChain(this.index + 1, request, this.interceptors); //获取节点信息 Interceptor interceptor = this.interceptors.get(this.index); Class aClass = interceptor.getClass(); log.info("当前节点：{}",aClass.getSimpleName()); ContractResponse response = interceptor.process(nextChain); if(Objects.isNull(response)){ throw new NullPointerException("intercetor"+interceptor+"return null"); } return response; } } ``` 到此**合同签章的架构流程已经确定**，后续只要填充`Interceptor`具体的实现类即可。在代码中`ContractResponse response = interceptor.process(nextChain);`来执行合同初始化节点的具体操作。 ``` /** * @author xbhog * @describe: 合同文本初始化 * @date 2023/7/12 */ @Slf4j @Component public class ContractSignCompactInitImpl implements Interceptor { public ContractSignCompactInitImpl() { } @Override public ContractResponse process(Chain chain) { log.info("=============执行合同文本初始化拦截器开始"); //获取处理的请求参数 T request = chain.request(); request.setStatus("1"); log.info("=============执行合同文本初始化拦截器结束"); //进入下一个责任链节点 ContractResponse response = chain.proceed(request); if(Objects.isNull(response)){ log.error("返回值的为空"); response = ContractResponse.builder().status("fail").mas("处理失败").build(); } //其他处理 return response; } } ``` ### 测试验证 ``` @SpringBootTest class SPringBootTestApplicationTests { @Autowired @Qualifier("contractSignProcessor") private Processor contractSignProcessor; @Test void contextLoads() { ContractRequest contractRequest = new ContractRequest(); contractRequest.setName("xbhog"); contractRequest.setAge("12"); ContractResponse process = contractSignProcessor.process(contractRequest); System.out.println(process); } } ``` 在这里只需要调用合同签章入口的方法即可进入合同签章的流程。 ``` 2023-07-16 13:25:13.063 INFO 26892 --- [ main] c.e.s.c.ContractSignProcessor : 签章开始 2023-07-16 13:25:13.067 INFO 26892 --- [ main] c.e.s.chainresponsibility.ContractChain : 当前节点：ContractSignCompactInitImpl 2023-07-16 13:25:13.068 INFO 26892 --- [ main] c.e.s.c.i.ContractSignCompactInitImpl : =============执行合同文本初始化拦截器开始 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.c.i.ContractSignCompactInitImpl : =============执行合同文本初始化拦截器结束 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.chainresponsibility.ContractChain : 当前节点：ContractSignGenerateImpl 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignGenerateImpl : =============执行合同文本生成拦截器开始 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignGenerateImpl : =============执行合同文本生成拦截器结束 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.chainresponsibility.ContractChain : 当前节点：ContractSignMockImpl 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignMockImpl : =============执行签章挡板拦截器开始 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignMockImpl : =============执行签章挡板拦截器结束 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.chainresponsibility.ContractChain : 当前节点：ContractSignMqImpl 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignMqImpl : =============执行合同签章完成发送mq拦截器开始 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.chainresponsibility.ContractChain : 当前节点：ContractSignSerialImpl 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignSerialImpl : =============执行合同签章流水处理拦截器开始 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.chainresponsibility.ContractChain : 当前节点：ContractSignSaveUploadImpl 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignSaveUploadImpl : =============执行合同签章完成上传服务器拦截器开始 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.chainresponsibility.ContractChain : 当前节点：ContractSignTradeImpl 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignTradeImpl : =============执行签章渠道实际调用拦截器开始 2023-07-16 13:25:13.069 INFO 26892 --- [ main] c.e.s.c.channel.ContractSignChannelImpl : 签章处理开始 2023-07-16 13:25:13.070 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignSaveUploadImpl : 开始上传服务器 2023-07-16 13:25:13.070 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignSaveUploadImpl : ............. 2023-07-16 13:25:13.070 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignSaveUploadImpl : 上传服务器完成 2023-07-16 13:25:13.070 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignSaveUploadImpl : =============执行合同签章完成上传服务器拦截器结束 2023-07-16 13:25:13.070 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignSerialImpl : =============执行合同签章流水处理拦截器结束 2023-07-16 13:25:13.070 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignMqImpl : 发送MQ给下游处理数据 2023-07-16 13:25:13.070 INFO 26892 --- [ main] c.e.s.c.impl.ContractSignMqImpl : =============执行合同签章完成发送mq拦截器结束 ContractResponse(status=success, mas=处理成功) ``` ## 策略+责任链+组合代码实现以下是完整的合同签章入口实现类： ``` /** * @author xbhog * @describe: 责任链+组合实现合同签章 * @date 2023/7/11 */ @Slf4j @Component public class ContractSignProcessor implements Processor { @Resource(name = "contractSignCompactInitImpl") private Interceptor contractCompactInitImpl; @Resource(name = "contractSignGenerateImpl") private Interceptor contractGenerateImpl; @Resource(name = "contractSignMockImpl") private Interceptor contractSignMockImpl; @Resource(name = "contractSignMqImpl") private Interceptor contractSignMqImpl; @Resource(name = "contractSignSaveUploadImpl") private Interceptor contractSignSaveUploadImpl; @Resource(name = "contractSignSerialImpl") private Interceptor contractSignSerialImpl; @Resource(name = "contractSignTradeImpl") private Interceptor ContractSignTradeImpl; public ContractSignProcessor() { } @Override public ContractResponse process(T paramter) { //获取所有的监听器 List> interceptorList = new ArrayList<>(); interceptorList.add(contractCompactInitImpl); interceptorList.add(contractGenerateImpl); interceptorList.add(contractSignMockImpl); interceptorList.add(contractSignMqImpl); interceptorList.add(contractSignSerialImpl); interceptorList.add(contractSignSaveUploadImpl); interceptorList.add(ContractSignTradeImpl); //开始签章 log.info("签章开始"); return new ContractCall(paramter,interceptorList).exectue(); } } ``` 可以看到，目前的合同签章的处理流程需要的节点数已经7个了，后续如果新增节点或者减少节点都需要对**该类进行手动的处理**；比如：减少一个节点的流程。 1. 删除节点实现的注入 0. 删除`list`中的bean实现类为方便后续的拓展(懒是社会进步的加速器，不是)，在**责任链，组合**的基础上通过**策略模式**来修改bean的注入方式。 **完整的项目结构和项目类图就是作者文章开始放的，可返回查看。** 在第一部分的基础上增加的功能点如下 1. 新增签章注解 0. 新增签章节点枚举 0. 新增签章配置类 ### 签章注解实现 ``` package com.example.springboottest.chainresponsibility.annotations; import com.example.springboottest.chainresponsibility.Enum.ContractSignEnum; import java.lang.annotation.*; /** * @author xbhog * @describe: * @date 2023/7/15 */ @Target(ElementType.TYPE) @Retention(RetentionPolicy.RUNTIME) public @interface ContractSign { ContractSignEnum.SignChannel SIGN_CHANNEL(); } ``` 设置注解修饰对象的范围，主要是对bean的一个注入，所以类型选择`type`, - TYPE: 用于描述类、接口(包括注解类型) 或enum声明设置注解的运行周期(有效范围)，一般是运行时有效， - RUNTIME：在运行时有效 **(大部分注解的选择)** 设置该注解的数据类型， - ENUM：枚举类型，方便统一处理 ### 枚举实现 ``` package com.xbhog.chainresponsibility.Enum; /** * @author xbhog * @describe: * @date 2023/7/15 */ public class ContractSignEnum { public enum SignChannel { SIGN_INIT(1, "合同文本初始化"), SIGN_GENERATE(2, "合同文本生成"), SIGN_MOCK(3, "签章挡板"), SIGN_MQ(4, "合同签章完成发送MQ"), SIGN_TABLE(5, "合同签章表处理"), SIGN_UPLOAD(6, "合同签章完成上传服务器"), SIGN_TRADE(7, "签章渠道实际调用"); private Integer code; private String info; SignChannel(Integer code, String info) { this.code = code; this.info = info; } ...... } } ``` 对合同签章中的流程节点进行统一的配置。 ### 签章配置类在项目启动的时候，通过注解工具类`AnnotationUtils`扫描所有被`ContractSign注解`修饰的类，将这些类通过Map进行存储，方便后续的调用。 ``` public class SignConfig { @Resource protected List contractSignList; protected static final Map CONTRACT_SIGN_MAP = new ConcurrentHashMap<>(); @PostConstruct public void init(){ contractSignList.forEach(interceptor -> { //查找这个接口的实现类上有没有ContractSign注解 ContractSign sign = AnnotationUtils.findAnnotation(interceptor.getClass(), ContractSign.class); if(!Objects.isNull(sign)){ CONTRACT_SIGN_MAP.put(sign.SIGN_CHANNEL().getCode(),interceptor); } }); } } ``` 到此，简化了Bean的注入方式。 ### 签章注解使用以合同文本初始化`ContractSignCompactInitImpl`来说。 ``` /** * @author xbhog * @describe: 合同文本初始化 * @date 2023/7/12 */ @Slf4j @ContractSign(SIGN_CHANNEL = ContractSignEnum.SignChannel.SIGN_INIT) @Component public class ContractSignCompactInitImpl implements Interceptor { public ContractSignCompactInitImpl() { } @Override public ContractResponse process(Chain chain) { log.info("=============执行合同文本初始化拦截器开始"); //获取处理的请求参数 T request = chain.request(); request.setStatus("1"); log.info("=============执行合同文本初始化拦截器结束"); //进入下一个责任链节点 ContractResponse response = chain.proceed(request); if(Objects.isNull(response)){ log.error("返回值的为空"); response = ContractResponse.builder().status("fail").mas("处理失败").build(); } //其他处理 return response; } } ``` 在该实现类上绑定了枚举`@ContractSign(SIGN_CHANNEL = ContractSignEnum.SignChannel.SIGN_INIT)`. **在合同签章入口类(** `**ContractSignProcessor**` **)中的变更如下：** ``` @Slf4j @Component public class ContractSignProcessor extends SignConfig implements Processor { public ContractSignProcessor() { } @Override public ContractResponse process(T paramter) { //获取所有的监听器 List> interceptorList = new ArrayList<>(); //获取排序后的结果，保证责任链的顺序，hashmap中key如果是数字的话，通过hashcode编码后是有序的 for(Integer key : CONTRACT_SIGN_MAP.keySet()){ interceptorList.add(CONTRACT_SIGN_MAP.get(key)); } //开始签章 log.info("签章开始"); return new ContractCall(paramter,interceptorList).exectue(); } } ``` 通过继承合同签章配置类(`SignConfig`)，来获取`Map`,遍历`Map添加到list`后进入责任链流程。 **到此，整个策略+责任链+组合的优化方式结束了。** * * * **问题：** **责任链中的顺序是怎么保证的？** 相信认真看完的你能在文章或者**代码中**找到答案。