前置内容
- 掌握策略模式
- 掌握责任链模式
- 掌握类继承、接口的实现
- 掌握参数的传递与设置
- GitHub地址
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
- 合同文本初始化
- 合同文本生成
- 签章挡板是否开启
- 合同签章发送mq
- 合同签章流水更新
- 合同上传文件服务器
- 签章渠道选择
- 签章渠道的实际调用
执行的流程如下：
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
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
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@Builderpublic class ContractRequest { private String name; private String age; private String status;}//响应@Data@NoArgsConstructor@AllArgsConstructor@Builderpublic 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@Componentpublic class ContractSignProcessor <T extends ContractRequest> implements Processor<T, ContractResponse> { @Resource(name = "contractSignCompactInitImpl") private Interceptor<T,ContractResponse> contractCompactInitImpl; ...... public ContractSignProcessor() { } @Override public ContractResponse process(T paramter) { //获取所有的监听器 List<Interceptor<T,ContractResponse>> 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<T extends ContractRequest> implements Call<T, ContractResponse> { private final T originalRequest; private final List<Interceptor<T,ContractRequest>> interceptorList; public ContractCall(T originalRequest, List<Interceptor<T, ContractRequest>> 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<T> 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 */@Slf4jpublic class ContractChain<T extends ContractRequest> implements Chain<T, ContractResponse> { private final Integer index; private final T request; private final List<Interceptor<T,ContractResponse>> interceptors; public ContractChain(Integer index, T request, List<Interceptor<T, ContractResponse>> 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<T,ContractResponse> nextChain = new ContractChain(this.index + 1, request, this.interceptors); //获取节点信息 Interceptor<T, ContractResponse> interceptor = this.interceptors.get(this.index); Class<? extends Interceptor> 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@Componentpublic class ContractSignCompactInitImpl<T extends ContractRequest> implements Interceptor<T, ContractResponse> { public ContractSignCompactInitImpl() { } @Override public ContractResponse process(Chain<T,ContractResponse> 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
@SpringBootTestclass SPringBootTestApplicationTests { @Autowired @Qualifier("contractSignProcessor") private Processor<ContractRequest,ContractResponse> 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：ContractSignCompactInitImpl2023-07-16 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：ContractSignGenerateImpl2023-07-16 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：ContractSignMockImpl2023-07-16 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：ContractSignMqImpl2023-07-16 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：ContractSignSerialImpl2023-07-16 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：ContractSignSaveUploadImpl2023-07-16 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：ContractSignTradeImpl2023-07-16 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@Componentpublic class ContractSignProcessor <T extends ContractRequest> implements Processor<T, ContractResponse> { @Resource(name = "contractSignCompactInitImpl") private Interceptor<T,ContractResponse> contractCompactInitImpl; @Resource(name = "contractSignGenerateImpl") private Interceptor<T,ContractResponse> contractGenerateImpl; @Resource(name = "contractSignMockImpl") private Interceptor<T,ContractResponse> contractSignMockImpl; @Resource(name = "contractSignMqImpl") private Interceptor<T,ContractResponse> contractSignMqImpl; @Resource(name = "contractSignSaveUploadImpl") private Interceptor<T,ContractResponse> contractSignSaveUploadImpl; @Resource(name = "contractSignSerialImpl") private Interceptor<T,ContractResponse> contractSignSerialImpl; @Resource(name = "contractSignTradeImpl") private Interceptor<T,ContractResponse> ContractSignTradeImpl; public ContractSignProcessor() { } @Override public ContractResponse process(T paramter) { //获取所有的监听器 List<Interceptor<T,ContractResponse>> 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。
- 删除节点实现的注入
- 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
- 新增签章注解
- 新增签章节点枚举
- 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，
设置该注解的数据类型，
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<Interceptor> contractSignList; protected static final Map<Integer,Interceptor> 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)@Componentpublic class ContractSignCompactInitImpl<T extends ContractRequest> implements Interceptor<T, ContractResponse> { public ContractSignCompactInitImpl() { } @Override public ContractResponse process(Chain<T,ContractResponse> 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@Componentpublic class ContractSignProcessor <T extends ContractRequest> extends SignConfig implements Processor<T, ContractResponse> { public ContractSignProcessor() { } @Override public ContractResponse process(T paramter) { //获取所有的监听器 List<Interceptor<T,ContractResponse>> 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。
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