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7.731s][info][gc,stats    ] === Garbage Collection Statistics =======================================================================================================================
[7.731s][info][gc,stats    ]                                                              Last 10s              Last 10m              Last 10h                Total
[7.731s][info][gc,stats    ]                                                              Avg / Max             Avg / Max             Avg / Max             Avg / Max
[7.731s][info][gc,stats    ]        Contention: Mark Segment Reset Contention                    23 / 164              23 / 164              23 / 164              23 / 164         ops/s
[7.731s][info][gc,stats    ]        Contention: Mark SeqNum Reset Contention                      0 / 2                 0 / 2                 0 / 2                 0 / 2           ops/s
[7.731s][info][gc,stats    ]          Critical: Allocation Stall                                  0 / 0                 0 / 0               

wkorando

-Xlog Usage: -Xlog[:[selections][:[output][:[decorators][:output-options]]]]
	 where 'selections' are combinations of tags and levels of the form tag1[+tag2...][*][=level][,...]
	 NOTE: Unless wildcard (*) is specified, only log messages tagged with exactly the tags specified will be matched.

Available log levels:
 off, trace, debug, info, warning, error

Available log decorators: 
 time (t), utctime (utc), uptime (u), timemillis (tm), uptimemillis (um), timenanos (tn), uptimenanos (un), hostname (hn), pid (p), tid (ti), level (l), tags (tg)
 Decorators can also be specified as 'none' for no decoration.

wkorando

public class TestUserService {
	
	@Test
	public void testFindUserExisting() {
		Map<Long, User> users = new HashMap<>();
		users.put(100L, new User(100L, "John", "Doe"));
		UserService service = new UserService(users, null);
		
		User returnedUser = service.findUser(100L);
		

wkorando

public class UserController {

	private UserService service;

	public UserController(UserService service) {
		this.service = service;
	}
	...
}

wkorando

@ExceptionHandler(ClientException.class)
public ResponseEntity<String> clientError(ClientException e) {
	return ResponseEntity.badRequest().body(e.getMessage());
}

@ExceptionHandler(NotFoundException.class)
public ResponseEntity<String> resourceNotFound(NotFoundException e) {
	return ResponseEntity.notFound().build();
}

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@Service
public class UserService {

	private List<User> users = new ArrayList<>();
	private static final Random ID_GENERATOR = new Random();

	public User findUser(long userId) {
		for(User user : users) {
			if(user.getId().equals(Long.valueOf(userId))) {
				return user;

wkorando

@RestController
@RequestMapping("/api/v1/users")
public class UserController {

	private UserService service;

	public UserController(UserService service) {
		this.service = service;
	}

wkorando

	@GetMapping("/header")
	public String welcomeUser(@RequestHeader String user) {
		return String.format("Welcome %s!", user);
	}

wkorando

	@GetMapping("/name")
	public String helloQueryMessage(@RequestParam String firstName, @RequestParam String lastName) {
		return String.format("Hello %s %s!", firstName, lastName);
	}

wkorando

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
			<optional>true</optional>
		</dependency>