spring - 无法写入 HTTP 消息 : org. springframework.http.converter.HttpMessageNotWritableException:找不到类型返回值的转换器:

Question

我正在尝试公开 REST 服务，但是当我从 POSTMAN 访问它时，我在下面:

警告:无法写入 HTTP 消息:org.springframework.http.converter.HttpMessageNotWritableException:找不到类型返回值的转换器:类 java.util.ArrayList

因为我还包含了以下所需的 jar 文件:

<dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.9.1</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.9.1</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-annotations</artifactId>
        <version>2.9.1</version>
    </dependency>

这是我的 REST Controller 代码:

@RestController
@RequestMapping("/MayankAPI")
public class TestRestAPI {
@RequestMapping(value="/sayHello" , method = RequestMethod.POST)
public TestPojo postData(@RequestBody String payload) {
  System.out.println("Hello post"+payload);
  TestPojo payload1=new TestPojo();
  payload1.setStudentName("Jack");
  return payload1;
}
@RequestMapping(value="/sayHello" , method = RequestMethod.GET)
public List<TestPojo> getData(String payload) {
  System.out.println("Hello get"+payload);
  List<TestPojo> payload1=new ArrayList<TestPojo>();
  TestPojo tp = new TestPojo();
  tp.setStudentName("Jack");
  payload1.add(tp);
  return payload1;
}

这是我要归还的 bean :

public class TestPojo {

  private String studentName;
  private String studentId;

  public String getStudentName() {
    return studentName;
  }

  public void setStudentName(String studentName) {
    this.studentName = studentName;
  }

  public String getStudentId() {
    return studentId;
  }

  public void setStudentId(String studentId) {
    this.studentId = studentId;
  }
}

请帮助我哪里做错了。

Answer 1

我知道为时已晚，但仍然替代解决方案:您需要将 Spring 项目启用为 Web MVC，如下所示:

@配置
@EnableWebMvc
@ComponentScan("basePackages = com.test")
公共(public)类 MiBenefitConfiguration
{
}