我有一堂简单的课

public class AuthenticationToken {

    public String token;

    public AuthenticationToken(String token) {
        this.token = token;
    }

    public String getToken() {
        return token;
    }

    public void setToken(String token) {
        this.token = token;
    }
}

使用杰克逊,我试图像这样将字符串映射到此对象

private String input = "{\"token\":\"adf\"}";


@Test
public void whenJsonString_ThenCreateAuthenticationObject() throws IOException {

    ObjectMapper jsonMapper = new ObjectMapper();
    AuthenticationToken tokenObject = jsonMapper.readValue(input,AuthenticationToken.class);
    assertThat(tokenObject).isNotNull();
}

但它引发以下异常

com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `foo.AuthenticationToken` (although at least one Creator exists): cannot deserialize from Object value (no delegate- or property-based Creator)
at [Source: (String)"{"token":"adf"}"; line: 1,column: 2]

我试图将AuthenticationToken中的属性注释为@JsonProperty,但这也导致了此异常.