Azure Spring Boot Function如何同时将触发器和输入绑定传入handleRequest方法

错误根因 #

你遇到的java.lang.UnsupportedOperationException: At the moment only Tuple-based function are supporting multiple arguments报错，是因为手动封装Reactor Tuple传入handleRequest时，Spring Cloud Function Azure适配器会将其识别为单个普通参数，不会当成多参数Tuple处理，因此无法匹配到对应的Function实现。

可行解决方案 #

方案1：自定义复合参数类（最推荐，兼容性最好） #

不需要依赖Tuple，新增一个POJO类封装所有需要传入的参数，适配所有版本的Spring Cloud Function Azure适配器。

1. 新增复合参数封装类

package com.att.trace.function.model;

public class FunctionInput {
    private User user;
    private String requestJson;

    public FunctionInput(User user, String requestJson) {
        this.user = user;
        this.requestJson = requestJson;
    }

    // 补全Getter方法
    public User getUser() {
        return user;
    }

    public String getRequestJson() {
        return requestJson;
    }
}

2. 调整Handler实现

public class HelloHandler extends FunctionInvoker<FunctionInput, String> {

        @FunctionName("hello")
        @StorageAccount("AzureWebJobsStorage")
        public HttpResponseMessage execute(
                        @HttpTrigger(name = "request", methods = { HttpMethod.GET,HttpMethod.POST }, authLevel = AuthorizationLevel.ANONYMOUS) HttpRequestMessage<Optional<User>> request,
                        @BlobInput(name = "requestjsonblob", dataType = "string", path = "requestjson/{name}.json") String requestjson,
                        ExecutionContext context) {
                User user = request.getBody().get();
                FunctionInput input = new FunctionInput(user, requestjson);
                handleRequest(input, context);
                return request.createResponseBuilder(HttpStatus.OK).body("ok")
                                .header("Content-Type", "application/json").build();
        }
}

3. 调整Spring Function实现

@Component
public class Hello implements Function<FunctionInput, String> {
  public String apply(FunctionInput input) {
    System.out.println("user=" + input.getUser());
    System.out.println("requestJson=" + input.getRequestJson());
    return "test output";
  }
}

方案2：使用BiFunction适配（无需新增POJO） #

Spring Cloud Function Azure适配器2.1.0及以上版本支持BiFunction类型的函数，可直接传入多参数，无需手动封装。

1. 调整Spring Function实现为BiFunction

@Component
public class Hello implements BiFunction<User, String, String> {
  public String apply(User user, String requestJson) {
    System.out.println("user=" + user);
    System.out.println("requestJson=" + requestJson);
    return "test output";
  }
}

2. 调整Handler传参逻辑，直接传入参数数组即可

public class HelloHandler extends FunctionInvoker<Object, String> {

        @FunctionName("hello")
        @StorageAccount("AzureWebJobsStorage")
        public HttpResponseMessage execute(
                        @HttpTrigger(name = "request", methods = { HttpMethod.GET,HttpMethod.POST }, authLevel = AuthorizationLevel.ANONYMOUS) HttpRequestMessage<Optional<User>> request,
                        @BlobInput(name = "requestjsonblob", dataType = "string", path = "requestjson/{name}.json") String requestjson,
                        ExecutionContext context) {
                User user = request.getBody().get();
                // 直接传入参数数组，适配器会自动匹配BiFunction
                handleRequest(new Object[]{user, requestjson}, context);
                return request.createResponseBuilder(HttpStatus.OK).body("ok")
                                .header("Content-Type", "application/json").build();
        }
}

注意：使用该方案需要确保spring-cloud-function-adapter-azure依赖版本不低于2.1.0.RELEASE，避免出现版本兼容问题。

内容的提问来源于stack exchange，提问作者Tarun Aghara