我正在使用Camel Jolt将输入JSON转换为其他格式的输出JSON，而我的Jolt JSON转换除了默认值之外不返回任何值（空或null）。它没有任何错误或警告我的代码，我会附上我所有的代码快照在这里。

pom.xml（依赖项）

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.apache.camel.springboot</groupId>
        <artifactId>camel-spring-boot-starter</artifactId>
        <version>4.0.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.camel.springboot</groupId>
        <artifactId>camel-jolt-starter</artifactId>
        <version>4.0.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.camel</groupId>
        <artifactId>camel-core</artifactId>
        <version>4.0.1</version>
    </dependency>
</dependencies>

CamelRoute.java

import org.apache.camel.builder.RouteBuilder;
import org.springframework.stereotype.Component;

@Component
public class CamelRoute extends RouteBuilder {

    @Override
    public void configure() throws Exception {
        from("direct:transformInput")
                .log("Received input JSON: ${body}")
                .to("jolt:classpath:jolt-spec.json") 
                .log("Transformed output JSON: ${body}")
                .to("log:finalOutput");
    }
}

jolt-spec.json

[
  {
    "operation": "shift",
    "spec": {
      "inputField1": "outputField1",
      "inputField2": "outputField2",
      "nestedObject": {
        "nestedField1": "outputNestedField1",
        "nestedField2": "outputNestedField2"
      }
    }
  }
]

TransformationController.java

import org.apache.camel.ProducerTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TransformationController {

    @Autowired
    private ProducerTemplate producerTemplate;

    @PostMapping("/transform")
    public String transform(@RequestBody String inputJson) {
        // Send input JSON for transformation
        String transformedOutput = producerTemplate.requestBody("direct:transformInput", inputJson, String.class);

        // You can return the transformedOutput or perform further actions
        return transformedOutput;
    }
}

我在我的postman中使用了以下输入json来点击[POST] http：//localhost：8080/transform

{
   "inputField1": "value1",
   "inputField2": "value2",
   "nestedObject": {
      "nestedField1": "nestedValue1",
      "nestedField2": "nestedValue2"
   }
}

程序运行良好，没有任何错误或警告。下面是我控制台日志：

23:44:23.393-04:00  INFO 29874 --- [nio-8080-exec-1] route1                                   : Received input JSON: {
   "inputField1": "value1",
   "inputField2": "value2",
   "nestedObject": {
      "nestedField1": "nestedValue1",
      "nestedField2": "nestedValue2"
   }
}
23:44:23.418-04:00  INFO 29874 --- [nio-8080-exec-1] route1                                   : Transformed output JSON: 
23:44:23.418-04:00  INFO 29874 --- [nio-8080-exec-1] finalOutput                              : Exchange[ExchangePattern: InOut, BodyType: null, Body: [Body is null]]

转换后的输出JSON为空或null，可能是什么原因？