SecurityController.java

package com.tutego.ch_09.security;

import org.springframework.security.core.Authentication;
import org.springframework.security.core.annotation.AuthenticationPrincipal;
import org.springframework.security.oauth2.jwt.Jwt;
import org.springframework.security.oauth2.jwt.JwtClaimsSet;
import org.springframework.security.oauth2.jwt.JwtEncoder;
import org.springframework.security.oauth2.jwt.JwtEncoderParameters;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.time.Instant;
import java.time.temporal.ChronoUnit;

@RestController
@RequestMapping("/security")
public class SecurityController {

    private final JwtEncoder jwtEncoder;

    public SecurityController(JwtEncoder jwtEncoder) {
        this.jwtEncoder = jwtEncoder;
    }

    @GetMapping("/tip")
    public String shortQuote() {
        return "Die with memories, not dreams.";
    }

    @GetMapping("/stats")
    public String numberOfRegisteredUnicorns(@AuthenticationPrincipal Jwt jwt) {
        return jwt.toString();
    }

    @GetMapping("/name")
    public String currentUserName(Authentication principal) {
        return principal.getName();
    }

    @PostMapping("/login")
    public String token(Authentication authentication) {
        var now = Instant.now();
        var claims = JwtClaimsSet.builder()
                .issuedAt(now)
                .expiresAt(now.plus(1, ChronoUnit.HOURS))
                .subject(authentication.getName())
                .build();

        return jwtEncoder.encode(JwtEncoderParameters.from(claims)).getTokenValue();
    }
}