Failed to convert JsonString.

[ghost]

How to convert an issue object to String? An error occurs during each conversion.

[bitwiseman]

@lwx979458 What error? Please provide details

[ghost]

@bitwiseman
The error reported is:
com.fasterxml.jackson.databind.JsonMappingException: Null key for a Map not allowed in JSON (use a converting NullKeySerializer?) (through reference chain: org.kohsuke.github.GHIssue["responseHeaderFields"]->java.util.Collections$UnmodifiableMap["null"])

The obtained issue object is in the following format:
GHIssue@4b14c583[assignee=,assignees={},state=open,number=997,comments=0,labels=[],title=WARNING [com.squareup.okhttp.OkHttpClient] (OkHttp ConnectionPool) A connection to https://api.github.com/ was leaked. Did you forget to close a response body?,milestone=,locked=false,url=https://api.github.com/repos//issues/997,id=755961400,nodeId=MDU6SXNzdWU3NTU5NjE0MDA=,createdAt=2020-12-03T07:58:18Z,updatedAt=2020-12-03T07:58:18Z]

So I'll make an error when I convert it to JsonString. How can I get the normal form Object?

[bitwiseman]

@lwx979458
Also please provide the actual stack trace from the "Null key for a Map not allowed in JSON" exception.

[ghost]

@bitwiseman
Sorry, I cannot find the corresponding Null key. I want to obtain full data of issues by page and convert the data to JsonString format. I do not know how to convert the data.

[bitwiseman]

You said:

The error reported is:
com.fasterxml.jackson.databind.JsonMappingException: Null key for a Map not allowed in JSON (use a converting NullKeySerializer?) (through reference chain: org.kohsuke.github.GHIssue["responseHeaderFields"]->java.util.Collections$UnmodifiableMap["null"])

Please provide the rest of the stack trace from that exception.

[ghost]

@bitwiseman
The value of FinalresponseHeaders contains a null key.

[ghost]

@bitwiseman
PagedIterator<GHIssue> issuePagedIterator = gitHub.getRepository("hub4j/github-api").listIssues(GHIssueState.OPEN)._iterator(100);
I use the pagination function to obtain issue data.The value of FinalresponseHeaders contains a null key. As a result, I cannot convert Object to JsonString.

[ghost]

@bitwiseman
issue.getResponseHeaderFields()
{null=[HTTP/1.1 200 OK], Access-Control-Allow-Origin=[*], ...}
As described above, the first key returned is null.

[ghost]

How can I convert the obtained issue object to JsonString?

[bitwiseman]

@lwx979458

Here's an example:

github-api/src/test/java/org/kohsuke/github/GitHubStaticTest.java

Lines 227 to 231 in 9151102

	GHRepository repo = getTempRepository();
	assertThat(repo.root, not(nullValue()));
	String repoString = GitHub.getMappingObjectWriter().writeValueAsString(repo);
	assertThat(repoString, not(nullValue()));

As a separate point, when someone asks for a stacktrace from an exception they mean something that looks like this:

java.io.FileNotFoundException: http://localhost:62277/app/installations/654321/access_tokens
	at org.kohsuke.github.extras.okhttp3.ObsoleteUrlFactory$OkHttpURLConnection.getInputStream(ObsoleteUrlFactory.java:488)
	at org.kohsuke.github.GitHubHttpUrlConnectionClient$HttpURLConnectionResponseInfo.bodyStream(GitHubHttpUrlConnectionClient.java:197)
	at org.kohsuke.github.GitHubResponse$ResponseInfo.getBodyAsString(GitHubResponse.java:326)
	at org.kohsuke.github.GitHubResponse.parseBody(GitHubResponse.java:91)
	at org.kohsuke.github.Requester.lambda$fetch$1(Requester.java:74)
	at org.kohsuke.github.GitHubClient.createResponse(GitHubClient.java:461)
	at org.kohsuke.github.GitHubClient.sendRequest(GitHubClient.java:412)
Caused: org.kohsuke.github.GHFileNotFoundException: http://localhost:62277/app/installations/654321/access_tokens {"message": "File not found"}
	at org.kohsuke.github.GitHubClient.interpretApiError(GitHubClient.java:492)
	at org.kohsuke.github.GitHubClient.sendRequest(GitHubClient.java:420)
	at org.kohsuke.github.GitHubClient.sendRequest(GitHubClient.java:363)
	at org.kohsuke.github.Requester.fetch(Requester.java:74)
... (more here clipped for clarity) ...

[ghost]

The org/kohsuke/github/GitHubResponse.java is modified to avoid the problem that the request header contains a null key.

TreeMap<String, List<String>> caseInsensitiveMap = new TreeMap<>(nullableCaseInsensitiveComparator);
for(String key: headers.keySet()){
    if(key != null){
        `caseInsensitiveMap.put(key, headers.get(key));
    }
}
this.headers = Collections.unmodifiableMap(caseInsensitiveMap);

[ghost]

GHIssue issue1 = gitHub.getRepository("hub4j/github-api").getIssue(997); 
System.out.println(JacksonJson.toJsonString(issue1));

com.fasterxml.jackson.databind.JsonMappingException: Null key for a Map not allowed in JSON (use a converting NullKeySerializer?) (through reference chain: org.kohsuke.github.GHIssue["responseHeaderFields"]->java.util.Collections$UnmodifiableMap["null"]) 
    at com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:285) 
    at com.fasterxml.jackson.databind.SerializerProvider.mappingException(SerializerProvider.java:1251) 
    at com.fasterxml.jackson.databind.SerializerProvider.reportMappingProblem(SerializerProvider.java:1145) 
    at com.fasterxml.jackson.databind.ser.impl.FailingSerializer.serialize(FailingSerializer.java:35) 
    at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeFields(MapSerializer.java:705) 
    at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:643) 
    at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:33) 
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:727) 
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:722) 
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) 
    at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider._serialize(DefaultSerializerProvider.java:480) 
    at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:319) 
    at com.fasterxml.jackson.databind.ObjectWriter$Prefetch.serialize(ObjectWriter.java:1433) 
    at com.fasterxml.jackson.databind.ObjectWriter._configAndWriteValue(ObjectWriter.java:1135) 
    at com.fasterxml.jackson.databind.ObjectWriter.writeValueAsString(ObjectWriter.java:1005) 
    at org.gitlab4j.api.utils.JacksonJson.marshal(JacksonJson.java:247) 
    at org.gitlab4j.api.utils.JacksonJson.toJsonString(JacksonJson.java:367) 
    at org.huawei.com.Test1.main(Test1.java:45) 
JsonMappingException, message=Null key for a Map not allowed in JSON (use a converting NullKeySerializer?) (through reference chain: org.kohsuke.github.GHIssue["responseHeaderFields"]->java.util.Collections$UnmodifiableMap["null"]) 
null

I resolved the null key problem in the request header. However, when an object of an issue is converted to a JsonString, the request is continuously initiated.

{Access-Control-Allow-Origin=[*], Access-Control-Expose-Headers=[ETag, Link, Location, Retry-After, X-GitHub-OTP, X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Used, X-RateLimit-Reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval, X-GitHub-Media-Type, Deprecation, Sunset], Cache-Control=[private, max-age=60, s-maxage=60], Connection=[Keep-Alive], Content-Security-Policy=[default-src 'none'], Content-Type=[application/json; charset=utf-8], Date=[Wed, 16 Dec 2020 03:00:10 GMT], ETag=[W/"71dc8958e466fd829f30f8e37854ea53717d068f334bb6ae86574859778d27bf"], Last-Modified=[Wed, 16 Dec 2020 02:33:43 GMT], Referrer-Policy=[origin-when-cross-origin, strict-origin-when-cross-origin], Server=[GitHub.com], Status=[200 OK], Strict-Transport-Security=[max-age=31536000; includeSubdomains; preload], Transfer-Encoding=[chunked], Vary=[Accept-Encoding, Accept, X-Requested-With, Accept, Authorization, Cookie, X-GitHub-OTP], via=[proxy A], X-Accepted-OAuth-Scopes=[repo], X-Content-Type-Options=[nosniff], X-Frame-Options=[deny], X-GitHub-Media-Type=[unknown, github.v3], X-GitHub-Request-Id=[3DEE:3ACF:465683:5966E2:5FD97839], X-OAuth-Scopes=[gist, read:org, repo], X-RateLimit-Limit=[5000], X-RateLimit-Remaining=[4996], X-RateLimit-Reset=[1608091208], X-RateLimit-Used=[4], X-XSS-Protection=[1; mode=block]}

{Access-Control-Allow-Origin=[*], Access-Control-Expose-Headers=[ETag, Link, Location, Retry-After, X-GitHub-OTP, X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Used, X-RateLimit-Reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval, X-GitHub-Media-Type, Deprecation, Sunset], Cache-Control=[private, max-age=60, s-maxage=60], Connection=[Keep-Alive], Content-Security-Policy=[default-src 'none'], Content-Type=[application/json; charset=utf-8], Date=[Wed, 16 Dec 2020 03:00:11 GMT], ETag=[W/"01d1a44c2c6b64a09d9abef7f49f6fac686a79f8c4f0c3d61b018ec9c5d4172d"], Referrer-Policy=[origin-when-cross-origin, strict-origin-when-cross-origin], Server=[GitHub.com], Status=[200 OK], Strict-Transport-Security=[max-age=31536000; includeSubdomains; preload], Transfer-Encoding=[chunked], Vary=[Accept-Encoding, Accept, X-Requested-With, Accept, Authorization, Cookie, X-GitHub-OTP], via=[proxy A], X-Accepted-OAuth-Scopes=[], X-Content-Type-Options=[nosniff], X-Frame-Options=[deny], X-GitHub-Media-Type=[unknown, github.v3], X-GitHub-Request-Id=[3DEE:3ACF:4656C5:59671E:5FD9783A], X-OAuth-Scopes=[gist, read:org, repo], X-RateLimit-Limit=[5000], X-RateLimit-Remaining=[4995], X-RateLimit-Reset=[1608091208], X-RateLimit-Used=[5], X-XSS-Protection=[1; mode=block]}

{Access-Control-Allow-Origin=[*], Access-Control-Expose-Headers=[ETag, Link, Location, Retry-After, X-GitHub-OTP, X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Used, X-RateLimit-Reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval, X-GitHub-Media-Type, Deprecation, Sunset], Cache-Control=[private, max-age=60, s-maxage=60], Connection=[Keep-Alive], Content-Security-Policy=[default-src 'none'], Content-Type=[application/json; charset=utf-8], Date=[Wed, 16 Dec 2020 03:00:11 GMT], ETag=[W/"388d579dbffb018a1b6de0c51e48703cfcb475beffc92952a335f6ed5ef11386"], Last-Modified=[Tue, 24 Nov 2020 19:23:21 GMT], Referrer-Policy=[origin-when-cross-origin, strict-origin-when-cross-origin], Server=[GitHub.com], Status=[200 OK], Strict-Transport-Security=[max-age=31536000; includeSubdomains; preload], Transfer-Encoding=[chunked], Vary=[Accept-Encoding, Accept, X-Requested-With, Accept, Authorization, Cookie, X-GitHub-OTP], via=[proxy A], X-Accepted-OAuth-Scopes=[], X-Content-Type-Options=[nosniff], X-Frame-Options=[deny], X-GitHub-Media-Type=[unknown, github.v3], X-GitHub-Request-Id=[3DEE:3ACF:4656EA:59675B:5FD9783B], X-OAuth-Scopes=[gist, read:org, repo], X-RateLimit-Limit=[5000], X-RateLimit-Remaining=[4994], X-RateLimit-Reset=[1608091208], X-RateLimit-Used=[6], X-XSS-Protection=[1; mode=block]}

{Access-Control-Allow-Origin=[*], Access-Control-Expose-Headers=[ETag, Link, Location, Retry-After, X-GitHub-OTP, X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Used, X-RateLimit-Reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval, X-GitHub-Media-Type, Deprecation, Sunset], Cache-Control=[private, max-age=60, s-maxage=60], Connection=[Keep-Alive], Content-Security-Policy=[default-src 'none'], Content-Type=[application/json; charset=utf-8], Date=[Wed, 16 Dec 2020 03:00:12 GMT], ETag=[W/"f1236c3c63f7bb598f3c3f9cdfeb27f7242625d6ff1dfdc00cd668350f13b60a"], Link=[<https://api.github.com/user/1958953/followers?page=2>; rel="next", <https://api.github.com/user/1958953/followers?page=6>; rel="last"], Referrer-Policy=[origin-when-cross-origin, strict-origin-when-cross-origin], Server=[GitHub.com], Status=[200 OK], Strict-Transport-Security=[max-age=31536000; includeSubdomains; preload], Transfer-Encoding=[chunked], Vary=[Accept-Encoding, Accept, X-Requested-With, Accept, Authorization, Cookie, X-GitHub-OTP], via=[proxy A], X-Accepted-OAuth-Scopes=[], X-Content-Type-Options=[nosniff], X-Frame-Options=[deny], X-GitHub-Media-Type=[unknown, github.v3], X-GitHub-Request-Id=[3DEE:3ACF:465703:596779:5FD9783B], X-OAuth-Scopes=[gist, read:org, repo], X-RateLimit-Limit=[5000], X-RateLimit-Remaining=[4993], X-RateLimit-Reset=[1608091208], X-RateLimit-Used=[7], X-XSS-Protection=[1; mode=block]}

{Access-Control-Allow-Origin=[*], Access-Control-Expose-Headers=[ETag, Link, Location, Retry-After, X-GitHub-OTP, X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Used, X-RateLimit-Reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval, X-GitHub-Media-Type, Deprecation, Sunset], Cache-Control=[private, max-age=60, s-maxage=60], Connection=[Keep-Alive], Content-Security-Policy=[default-src 'none'], Content-Type=[application/json; charset=utf-8], Date=[Wed, 16 Dec 2020 03:00:12 GMT], ETag=[W/"05cf42714b3f09c7017bd735bfda5ea6420cb88526a8678ecf74d87501ca36ed"], Link=[<https://api.github.com/user/1958953/followers?page=1>; rel="prev", <https://api.github.com/user/1958953/followers?page=3>; rel="next", <https://api.github.com/user/1958953/followers?page=6>; rel="last", <https://api.github.com/user/1958953/followers?page=1>; rel="first"], Referrer-Policy=[origin-when-cross-origin, strict-origin-when-cross-origin], Server=[GitHub.com], Status=[200 OK], Strict-Transport-Security=[max-age=31536000; includeSubdomains; preload], Transfer-Encoding=[chunked], Vary=[Accept-Encoding, Accept, X-Requested-With, Accept, Authorization, Cookie, X-GitHub-OTP], via=[proxy A], X-Accepted-OAuth-Scopes=[], X-Content-Type-Options=[nosniff], X-Frame-Options=[deny], X-GitHub-Media-Type=[unknown, github.v3], X-GitHub-Request-Id=[3DEE:3ACF:465727:5967A4:5FD9783C], X-OAuth-Scopes=[gist, read:org, repo], X-RateLimit-Limit=[5000], X-RateLimit-Remaining=[4992], X-RateLimit-Reset=[1608091208], X-RateLimit-Used=[8], X-XSS-Protection=[1; mode=block]}

...

[bitwiseman]

@lwx979458 (I updated your comment to use code blocks (triple-backtick).

Okay, this is bug. I see the problem. Certain fields that should be transient are not. I'll get a PR up for this when I have the chance. In the meanwhile, you can manually exclude root and responseHeaderFields (and any other problem field) using one of the techniques here: https://stackoverflow.com/questions/13764280/how-do-i-exclude-fields-with-jackson-not-using-annotations .