HttpURLConnection will silently retry DELETE requests. This behavior is similar to other existing JDK bugs (JDK-6382788, JDK-6427251). google-http-java-client already contains a workaround (NetHttpRequest.java#L108-L112) for those requests which have a body, but does not account for DELETE with an empty body.
For Google Cloud Storage, while developing a conformance test suite for retry handling I ran into this bug and will submit a fix.
OS type and version: Debian Linux
openjdk version "1.8.0_292"
OpenJDK Runtime Environment (AdoptOpenJDK)(build 1.8.0_292-b10)
OpenJDK 64-Bit Server VM (AdoptOpenJDK)(build 25.292-b10, mixed mode)
google-http-client version(s): 1.40.0 and older
Steps to reproduce
start a "server" which closes the connection without sending a response