NullPointerException thrown from JdkClientHttpRequestFactory for null request header value #35996
Description
I'm migrating my Spring/Springboot application and found a strange behavior:
This code worked on SpringBoot 3.2.5
HttpHeaders headers = new HttpHeaders(); headers.setContentType(MediaType.APPLICATION_JSON); headers.add("rid", SOME_VALUE_THAT_CAN_BE_NULL)); HttpEntity<Object> entity = new HttpEntity<>(headers); ResponseEntity<T> response = restTemplate.exchange(host + apiUrl, HttpMethod.GET, entity, clazz); return response.getBody(); Actual Version: SpringBoot 3.5.8
it raises a NPE. See the stackstrace:
java.lang.NullPointerException: value at java.base/java.util.Objects.requireNonNull(Objects.java:246) at java.net.http/jdk.internal.net.http.HttpRequestBuilderImpl.checkNameAndValue(HttpRequestBuilderImpl.java:108) at java.net.http/jdk.internal.net.http.HttpRequestBuilderImpl.header(HttpRequestBuilderImpl.java:129) at java.net.http/jdk.internal.net.http.HttpRequestBuilderImpl.header(HttpRequestBuilderImpl.java:45) at org.springframework.http.client.JdkClientHttpRequest.lambda$buildRequest$0(JdkClientHttpRequest.java:158) at java.base/java.util.LinkedHashMap.forEach(LinkedHashMap.java:987) at org.springframework.util.LinkedCaseInsensitiveMap.forEach(LinkedCaseInsensitiveMap.java:292) at org.springframework.util.MultiValueMapAdapter.forEach(MultiValueMapAdapter.java:179) at org.springframework.http.HttpHeaders.forEach(HttpHeaders.java:1904) at org.springframework.http.client.JdkClientHttpRequest.buildRequest(JdkClientHttpRequest.java:155) at org.springframework.http.client.JdkClientHttpRequest.executeInternal(JdkClientHttpRequest.java:103) at org.springframework.http.client.AbstractStreamingClientHttpRequest.executeInternal(AbstractStreamingClientHttpRequest.java:88) at org.springframework.http.client.AbstractClientHttpRequest.execute(AbstractClientHttpRequest.java:81) at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:900) at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:801) at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:683) If I put a simple IF around headers.add("rid", SOME_VALUE_THAT_CAN_BE_NULL)); it works.
I couldn't find a doc about this.
What causes the use of jdk.internal.net.http.HttpRequestBuilderImpl.header ?
Looks like older version uses SimpleClientHttpRequest and addHeaders method has this line 115 String actualHeaderValue = headerValue != null ? headerValue : "";
Can we add some docs about this? I can write, just need to understand this new behavior first.
Thanks!