当我从@RestControler返回对象时，如何在json中保持地图键顺序 [英] How to keep map key order in json when I return object from @RestControler

问题描述

我想保持地图条目的顺序，因此我在上下文中添加了以下bean:

I want to keep map entries order thus I've added following bean into context:

@Bean
public ObjectMapper objectMapper() {
    ObjectMapper objectMapper = new ObjectMapper();
    objectMapper.configure(SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS, true);
    return objectMapper;
}

我还有以下控制器:

@Autowired
private ObjectMapper objectMapper;
@GetMapping(value = "/mapping", produces = "application/json")
public ResponseEntity<MappingDTO> getMapping(HttpServletRequest request) {
    MappingDTO mappingDTO = mappingService.getMapping();
    String str = objectMapper.writeValueAsString(mappingDTO); // added this line for test perpose
    return ResponseEntity.ok(mappingDTO);
}

dto:

public class MappingDTO {
    private String id;
    private Map<String, List<MappingEntry>> entries;
    ...

str变量包含正确顺序的正确json，但是当我执行Get请求时-顺序被破坏了.

str variable contains correct json with correct order but when I execute Get request - order is broken.

如何解决此问题?

推荐答案

假设您希望按字典顺序对键进行排序，请添加

Assuming you want keys sorted lexicographically, add

spring.jackson.serialization.order-map-entries-by-keys=true

到application.properties文件.

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