My favorite features when upgrade from java 8 to java 11

1. A new HttpClient/HttpRequest/HttpResponse/WebSocket:

HttpRequest request = HttpRequest.newBuilder()
  .uri(new URI("https://postman-echo.com/get"))
  .GET()
  .build();

HttpResponse<String> response = HttpClient.newHttpClient()
  .send(request, HttpResponse.BodyHandler.asString());

2. Process handler
ProcessHandle self = ProcessHandle.current();
long PID = self.getPid();
ProcessHandle.Info procInfo = self.info();
 
Optional<String[]> args = procInfo.arguments();
Optional<String> cmd =  procInfo.commandLine();
Optional<Instant> startTime = procInfo.startInstant();
Optional<Duration> cpuUsage = procInfo.totalCpuDuration()

3. Destroying child process
childProc = ProcessHandle.current().children();
childProc.forEach(procHandle -> {
    assertTrue("Could not kill process " + procHandle.getPid(), procHandle.destroy());
});

4. JSheel command line to verify the simple snip code.
5. Immutable Set and Map
Set<String> sets = Set.of("v1", "v2", "v3");
Map<String, String> maps = Map.of(“k1”, “v1”, “k2”, “v2”); (max support 10 entry)

6. Allow annotation to the lambada parameter:
list.stream() .map((@Notnull var s) -> s.toLowerCase()) .collect(Collectors.toList());

7. java.util.function.Predicate:not
lines.stream() .filter(Predicate.not(String::isBlank))

8. local var type inference
var x = new … , (should be argued if we need use it for daily work or not).
               
9. New copyOf method for List, Map, Set interface
10. java.util.stream.Collectors: toUnmodifiableList/ toUnmodifiableSet  to provide unmodified set.
11. Lunch java code directly:
java HelloWorld.java  = {javac HelloWorld; java HelloWorld}