Implementing a Responsibility Chain Pattern with Spring Boot and MyBatis Plus

Background : The project exposes an OpenAPI interface that contains dozens of functional points (parameter validation, configuration checks, data persistence, messaging, etc.). Different downstream clients require different subsets of these functions.

Idea : Split each functional point into an independent component and link them using the Chain of Responsibility pattern. The execution order can be defined dynamically (e.g., stored in a database or passed via a request).

Key Implementation :

Define an abstract class ComponentAbstract.java that provides handlerRequest(Contxt contxt) to measure execution time and delegate to an abstract doHandler(Contxt contxt) method.

Create concrete handlers ( Test1.java , Test2.java , Test3.java , Test4.java ) annotated with @Component("1") , @Component("2") … Each overrides doHandler to modify a shared context.

Shared context class Contxt.java holds fields such as name , age , adrss , userid and is annotated with Lombok’s @Data , @Builder , etc.

Utility AopProxyUtils.java implements ApplicationContextAware to retrieve Spring‑managed beans by name.

Controller LiteFlowController.java exposes /test/chain . It parses the index query parameter (e.g., 2,1,3,4 ), obtains the corresponding beans via AopProxyUtils.getProxyBean(className) , invokes handlerRequest in the specified order, and returns the final Contxt as JSON.

Sample Code Snippets :

public abstract class ComponentAbstract {
    public void handlerRequest(Contxt contxt) {
        // measure execution time
        this.doHandler(contxt);
    }
    public abstract void doHandler(Contxt contxt);
}

@Component("1")
public class Test1 extends ComponentAbstract {
    @Override
    public void doHandler(Contxt contxt) {
        log.info("Test1-顺序1-上下文内容为：{}", JSON.toJSONString(contxt));
        contxt.setName("Test1");
        // other fields set …
    }
}

@Data @Builder @AllArgsConstructor @NoArgsConstructor
public class Contxt {
    private String name;
    private String age;
    private String adrss;
    private String userid;
}

@RestController
@RequestMapping("/test")
public class LiteFlowController {
    @GetMapping("chain")
    public String pattern(@RequestParam String index) {
        Contxt contxt = Contxt.builder()
            .name("初始化").age("初始化").adrss("初始化").userid("初始化").build();
        for (String className : index.split(",")) {
            ComponentAbstract handler = (ComponentAbstract) AopProxyUtils.getProxyBean(className);
            if (handler != null) {
                handler.handlerRequest(contxt);
            }
        }
        return JSON.toJSONString(contxt);
    }
}

Note : While a custom implementation is shown, the author mentions that the LiteFlow framework would be a more suitable choice for production use.