java - Jackson 对象映射器在响应中包含转义序列

Question

当我使用对象映射器时，它会在响应中包含\r\n。请帮助我如何解决它。我正在训练 POJO，它有字符串名称和字符串值。我将名称设置为“Sydney”，并将值设置为“SYD”。它重新运行

{\ \ \"name \" : \"Sydney\",\ \ \"Value \" : \"SYD\",\ \ \"isEnable\" : false,\ \ \"isCurrent\" : false\ \ }"

浏览器中的原始值

"{\r\n  \"name\" : \"Sydney\",\r\n  \"name\" : \"SYD\",\r\n  \"isEnable\" : false,\r\n  \"isCurrent\" : false\r\n}"

下面是我的代码火车

public class Train {

    public Train() {
    }


    private String name;
    private String value; 
    private String Code;
    private String countryName;
    private String state;
    private String stateName;
    private boolean isEnable;
    private boolean isCurrent;

    //*getters and setters/*/
    }

Controller 类

public ResponseEntity<String> getDetails(   )       
            throws IOException {
        ResponseEntity<String> responseEntity = null;

        try(StringWriter writer = new StringWriter()) {
            ObjectMapper mapper = new ObjectMapper();           
            Train train = new Train();
          // set name and value to the train object//

             if(train != null)
             {
                mapper.setSerializationInclusion(Inclusion.NON_NULL);
                mapper.setSerializationInclusion(Inclusion.NON_EMPTY);

             mapper.writerWithDefaultPrettyPrinter().writeValue(writer,
                    train);         
            responseEntity = new ResponseEntity<>(writer.toString(),
                    HttpStatus.OK);
             }
             }
          catch()
             {}              
             return responseEntity;
             }

配置:

@Override
    public void configureMessageConverters(
            List<HttpMessageConverter<?>> converters) {
        converters.add(extendedJsonConvertor());
        super.configureMessageConverters(converters);
    }

    @Bean
    public MappingJackson2HttpMessageConverter extendedJsonConvertor() {
        MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter = new MappingJackson2HttpMessageConverter();

        mappingJackson2HttpMessageConverter
                .setObjectMapper(getNullAndEmptyFilteredObjectMapper());
        return mappingJackson2HttpMessageConverter;
    }

    @Bean
    public ObjectMapper getNullAndEmptyFilteredObjectMapper() {
        ObjectMapper objectMapper = new ObjectMapper();     
        objectMapper.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);
        objectMapper.configure(
                DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        return objectMapper;
    }

当我调试上面的代码时，我开始知道映射器在响应中包含那些\r\n 。帮助我如何删除那些斜杠。

Answer 1

问题出在下面这一行。

mapper.writerWithDefaultPrettyPrinter().writeValue(writer,train);  

尝试将其替换为

mapper.writeValue(writer,train);

为什么在配置的时候要新建一个对象映射器，MappingJackson2HttpMessageConverter？
您可以 Autowiring 对象映射器或返回实际对象并让 spring 将其转换为 json