프로젝트 생성

의존성 추가

plugins {
	id 'java'
	id 'org.springframework.boot' version '3.3.0'
	id 'io.spring.dependency-management' version '1.1.5'
}

group = 'com.jwt'
version = '0.0.1-SNAPSHOT'

java {
	toolchain {
		languageVersion = JavaLanguageVersion.of(17)
	}
}

configurations {
	compileOnly {
		extendsFrom annotationProcessor
	}
}

repositories {
	mavenCentral()
}

dependencies {
//	implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
	implementation 'org.springframework.boot:spring-boot-starter-security'
	implementation 'org.springframework.boot:spring-boot-starter-web'
	compileOnly 'org.projectlombok:lombok'
//	runtimeOnly 'com.mysql:mysql-connector-j'
	annotationProcessor 'org.projectlombok:lombok'
	testImplementation 'org.springframework.boot:spring-boot-starter-test'
	testImplementation 'org.springframework.security:spring-security-test'
	testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
	implementation 'io.jsonwebtoken:jjwt-api:0.12.3'
	implementation 'io.jsonwebtoken:jjwt-impl:0.12.3'
	implementation 'io.jsonwebtoken:jjwt-jackson:0.12.3'
}

tasks.named('test') {
	useJUnitPlatform()
}

기본적인 컨트롤러 작성

package com.jwt.jwtstudy_youtube.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
@ResponseBody
public class MainController {

    @GetMapping("/")
    public String mainP() {

        return "main Controller";
    }
}

package com.jwt.jwtstudy_youtube.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
@ResponseBody
public class AdminController {

    @GetMapping("/admin")
    public String adminP() {

        return "admin Controller";
    }
}

SecurityConfig 작성

package com.jwt.jwtstudy_youtube.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.http.SessionCreationPolicy;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.web.SecurityFilterChain;

@Configuration
@EnableWebSecurity //security를 위한 것이라고 알려주는 기능
public class SecurityConfig {


    @Bean
    public BCryptPasswordEncoder bCryptPasswordEncoder() {

        return new BCryptPasswordEncoder();
    }

    @Bean
    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {


        http
                .csrf((auth) -> auth.disable())
                //From로그인 사용안함
                .formLogin((auth) -> auth.disable())
                .httpBasic((auth) -> auth.disable())
                .authorizeHttpRequests((auth) -> auth
                        .requestMatchers("/login", "/", "join").permitAll()
                        .requestMatchers("/admin").hasRole("ADMIN")
                        .anyRequest().authenticated())
                //jwt는 세션리스 서버!!!
                .sessionManagement((session) -> session
                        .sessionCreationPolicy(SessionCreationPolicy.STATELESS));

        return http.build();
    }
}