GSON 无法使用字符串空间解析 JSON

Question

I have the following object:

public class ParameterWrapper<T> {

    private String type;

    private T value;

    public ParameterWrapper(String type, T value) {
        this.type = type;
        this.value = value;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public T getValue() {
        return value;
    }

    public void setValue(T value) {
        this.value = value;
    }
}

I am serializing it into JSON using the Gson library. When value contains a string with no spaces, it works perfectly. When value contains a string with spaces, I see the following exception:

com.google.gson.JsonSyntaxException: com.google.gson.stream.MalformedJsonException: Unterminated object at line 1 column 28

For the following JSON:

{"Plaintext":{"type":"String","value":"hello there"},"Key":{"type":"Number","value":"1"},"SINGLE_FUNCTION":{"value":"1-0"}}

However with the following:

{"Plaintext":{"type":"String","value":"hellothere"},"Key":{"type":"Number","value":"1"},"SINGLE_FUNCTION":{"value":"1-0"}}

The JSON is parsed successfully. Is this a known issue? I've ran the JSON through a validator and it is perfectly fine.

Edit:

The vagueness of the question wasn't unnoticed. I was hoping this was an existing issue. The application is huge, which is why prying out a small, compilable example is difficult, but I'll do what I can!

OKAY. So firstly, the below JSON is send to my controller:

@RequestMapping("/update-state")
public
@ResponseBody
String updateState(@RequestParam(value = "algorithmId") String algorithmId,
                   @RequestParam(value = "state") String state) throws InvalidParameterException {

    Algorithm algorithm = algorithmService.getAlgorithmById(Integer.parseInt(algorithmId));
    algorithm.execute(executorService.parseAlgorithmState(state));

    return gsonBuilder.toJson(algorithm.getState().getParameterMap());
}

On the call to parseAlgorithmState(state) , it moves down to this method:

@Override
public AlgorithmState parseAlgorithmState(String json) throws InvalidParameterException {
    Gson gson = new Gson();
    Map keyValueMap = (Map) gson.fromJson(json.trim(), Object.class);
    ...

The line Map keyValueMap = (Map) gson.fromJson(json.trim(), Object.class); is where the exception is initially occurring.

Answer 1

So after some discussion, the following workaround worked:

Gson gson = new Gson(); 
JsonReader jr = new JsonReader(new StringReader(s.trim())); 
jr.setLenient(true); 
Map keyValueMap = (Map) gson.fromJson(jr, Object.class);

setLenient(true) makes the parser a bit less restrictive.

Looking at the documentation every restrictions that setLenient(true) disable are not present in your Json string, except the first one (which may be the issue since you're getting the string from a webserver).

Answer 2

I just had this same issue. The problem is that the character is a non-breaking space, char(160). If you paste this in the body of a request using POSTMAN, you'll visually be able to see the characters (They look like gray dots). Gson doesn't like them.

Answer 3

This worked for me

  Gson gson = new Gson(); 
  Map keyValueMap = (Map) gson.fromJson(gson.toJson(s.trim()), Object.class);

Answer 4

I got the same error with this JSON:

{“id”:“”,“title”:“Hello SiteCore”,“description”:“This is the body text from SiteCore”,“type”:“Information”,“displayType”:“Banner”}

The parser was pointing to the char coming right after the first white space.

com.google.gson.JsonSyntaxException: com.google.gson.stream.MalformedJsonException: Unterminated object at line 1 column 26 path $.null

After much search and having some extra pairs of eyes, we found that the JSON (coming from a Sitecore database) has been created with “ instead of " .

Changing all “ chars to " solved my problem using the usual Gson code:

    @JvmStatic
    fun convertFromJsonString(data: String): Message? {
        if (data.isEmpty())
            return null
        return Gson().fromJson(data, Message::class.java)
    }

Hope this helps someone in the future.