Motivation:
https in xmlns URIs does not work and will let the maven release plugin fail:
```
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.779 s
[INFO] Finished at: 2020-11-10T07:45:21Z
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-release-plugin:2.5.3:prepare (default-cli) on project netty-parent: Execution default-cli of goal org.apache.maven.plugins:maven-release-plugin:2.5.3:prepare failed: The namespace xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" could not be added as a namespace to "project": The namespace prefix "xsi" collides with an additional namespace declared by the element -> [Help 1]
[ERROR]
```
See also https://issues.apache.org/jira/browse/HBASE-24014.
Modifications:
Use http for xmlns
Result:
Be able to use maven release plugin
Motivation:
HTTP is a plaintext protocol which means that someone may be able
to eavesdrop the data. To prevent this, HTTPS should be used whenever
possible. However, maintaining using https:// in all URLs may be
difficult. The nohttp tool can help here. The tool scans all the files
in a repository and reports where http:// is used.
Modifications:
- Added nohttp (via checkstyle) into the build process.
- Suppressed findings for the websites
that don't support HTTPS or that are not reachable
Result:
- Prevent using HTTP in the future.
- Encourage users to use HTTPS when they follow the links they found in
the code.
Motivation:
Socks5InitialRequestDecoder does not correctly handle fragmentation
Modifications:
- Delete detection of not enough bytes as ReplyingDecoder already handles all of this correctly.
- Add unit test
Result:
Fixes#9574.
Motivation:
There appears to be a thread-safety issue in the way that `SocksAuthRequest` is using its `CharsetEncoder` instance. `CharsetUtil#encoder` returns a cached thread-local encoder instance, so it is not correct to store this instance in a static member variable and reuse it across multiple threads. The result is an occasional `IllegalStateException` as in the following example:
```
java.lang.IllegalStateException: Current state = RESET, new state = FLUSHED
at java.base/java.nio.charset.CharsetEncoder.throwIllegalStateException(CharsetEncoder.java:989)
at java.base/java.nio.charset.CharsetEncoder.flush(CharsetEncoder.java:672)
at java.base/java.nio.charset.CharsetEncoder.encode(CharsetEncoder.java:801)
at java.base/java.nio.charset.CharsetEncoder.canEncode(CharsetEncoder.java:907)
at java.base/java.nio.charset.CharsetEncoder.canEncode(CharsetEncoder.java:982)
at io.netty.handler.codec.socks.SocksAuthRequest.<init>(SocksAuthRequest.java:43)
```
Modification:
Instead of retrieving the thread-local encoder instance once and storing it as a static member instance, the encoder should be retrieved each time the constructor is invoked. This change prevents any potential concurrency issues where multiple threads may end up using the same encoder instance.
Result:
Fixes#9556.
