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没有双重序列化的Spring-Return原始JSON

jackson spring-boot spring-mvc json

Cody Pritchard · 技术社区 · 7 年前

我知道还有其他类似的帖子,但我还没有找到任何能帮助我找到解决这个特殊情况的方法。

我正试着归还一张支票 HashMap<String, Object> 从我的控制器。这个 Object

控制器功能:

@RequestMapping(method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
public HashMap<String, Object> heartbeat(){
    String streamInfo = service.getStreamInfo();
    String streamCursorInfo = service.getStreamCursorInfo();
    String topicInfo = service.getTopicInfo();

    String greeting = "This is a sample app for using Spring Boot with MapR Streams.";

    HashMap<String, Object> results = new HashMap();
    results.put("greeting", greeting);
    results.put("streamInfo", streamInfo);
    results.put("streamCursorInfo", streamCursorInfo);
    results.put("topicInfo", topicInfo);

    return results;
}

服务功能:

private String performCURL(String[] command){
    StringBuilder stringBuilder = new StringBuilder();

    try{
        ProcessBuilder processBuilder = new ProcessBuilder(command);
        Process p = processBuilder.start();

        BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
        String line = null;
        while((line = reader.readLine()) != null){
            stringBuilder.append(line);
        }
    }
    catch(Exception e){
        LOGGER.error(ExceptionUtils.getRootCauseMessage(e));
    }

    return stringBuilder.toString();
}

我运行的cURL命令已经返回了一个原始的JSON字符串。所以我只是想把它添加到HashMap中,在heartbeat响应中返回。

{
"greeting": "This is a sample app for using Spring Boot with MapR Streams.",
"streamCursorInfo": "{\"timestamp\":1538676344564,\"timeofday\":\"2018-10-04 02:05:44.564 GMT-0400 PM\",\"status\":\"OK\",\"total\":1,\"data\":[{\"consumergroup\":\"MapRDBConsumerGroup\",\"topic\":\"weightTags\",\"partitionid\":\"0\",\"produceroffset\":\"44707\",\"committedoffset\":\"10001\",\"producertimestamp\":\"2018-10-03T05:57:27.128-0400 PM\",\"consumertimestamp\":\"2018-09-21T12:35:51.654-0400 PM\",\"consumerlagmillis\":\"1056095474\"}]}",
...
}

streamInfo

有人能解释我遗漏了什么或者需要做什么来防止双重序列化吗?

2 回复 | 直到 7 年前

Wim Deblauwe 7 年前

而不是返回 HashMap ,创建如下对象:

public class HeartbeatResult {
  private String greeting;
  ... //other fields here

  @JsonRawValue
  private String streamCursorInfo;

  ... //getters and setters here (or make the object immutable by having just a constructor and getters)
}

与 @JsonRawValue 杰克逊将按原样序列化字符串。看到了吗 https://www.baeldung.com/jackson-annotations 更多信息。

Adina Rolea 7 年前

streamCursorInfo是字符串,而不是对象=>序列化将转义“字符”。

ObjectMapper objectMapper = new ObjectMapper();

JsonNode streamCursorInfo = objectMapper.readTree(service.getStreamInfo())

results.put("streamCursorInfo", streamCursorInfo);

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