springsecurity+jwt实现单点登录代码流程

Spring Security结合JWT实现单点登录的代码流程如下：

1. 创建一个Spring Boot项目并添加以下依赖：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt</artifactId>
    <version>0.9.1</version>
</dependency>

2. 在Spring Security配置类中添加以下代码：

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private JwtAuthenticationEntryPoint unauthorizedHandler;

    @Autowired
    private CustomUserDetailsService customUserDetailsService;

    @Value("${jwt.secret}")
    private String secret;

    @Value("${jwt.expiration}")
    private int expiration;

    @Bean
    public JwtAuthenticationFilter authenticationTokenFilter() {
        return new JwtAuthenticationFilter();
    }

    @Override
    public void configure(AuthenticationManagerBuilder authenticationManagerBuilder) throws Exception {
        authenticationManagerBuilder
                .userDetailsService(customUserDetailsService)
                .passwordEncoder(passwordEncoder());
    }

    @Bean(BeanIds.AUTHENTICATION_MANAGER)
    @Override
    public AuthenticationManager authenticationManagerBean() throws Exception {
        return super.authenticationManagerBean();
    }

    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
                .cors()
                    .and()
                .csrf()
                    .disable()
                .exceptionHandling()
                    .authenticationEntryPoint(unauthorizedHandler)
                    .and()
                .sessionManagement()
                    .sessionCreationPolicy(SessionCreationPolicy.STATELESS)
                    .and()
                .authorizeRequests()
                    .antMatchers("/api/auth/**")
                        .permitAll()
                    .anyRequest()
                        .authenticated();

        // 添加JWT过滤器
        http.addFilterBefore(authenticationTokenFilter(), UsernamePasswordAuthenticationFilter.class);
    }

    @Bean
    public JwtTokenProvider jwtTokenProvider() {
        return new JwtTokenProvider(secret, expiration);
    }
}

3. 创建一个JwtTokenProvider类，实现JWT的生成、解析和验证：

@Service
public class JwtTokenProvider {

    private final String secret;
    private final long expiration;

    @Autowired
    public JwtTokenProvider(@Value("${jwt.secret}") String secret, @Value("${jwt.expiration}") long expiration) {
        this.secret = secret;
        this.expiration = expiration;
    }

    public String generateToken(Authentication authentication) {
        UserPrincipal userPrincipal = (UserPrincipal) authentication.getPrincipal();
        Date now = new Date();
        Date expiryDate = new Date(now.getTime() + expiration);

        return Jwts.builder()
                .setSubject(Long.toString(userPrincipal.getId()))
                .setIssuedAt(new Date())
                .setExpiration(expiryDate)
                .signWith(SignatureAlgorithm.HS512, secret)
                .compact();
    }

    public Long getUserIdFromToken(String token) {
        Claims claims = Jwts.parser()
                .setSigningKey(secret)
                .parseClaimsJws(token)
                .getBody();

        return Long.parseLong(claims.getSubject());
    }

    public boolean validateToken(String token) {
        try {
            Jwts.parser().setSigningKey(secret).parseClaimsJws(token);
            return true;
        } catch (SignatureException ex) {
            System.out.println("Invalid JWT signature");
        } catch (MalformedJwtException ex) {
            System.out.println("Invalid JWT token");
        } catch (ExpiredJwtException ex) {
            System.out.println("Expired JWT token");
        } catch (UnsupportedJwtException ex) {
            System.out.println("Unsupported JWT token");
        } catch (IllegalArgumentException ex) {
            System.out.println("JWT claims string is empty.");
        }
        return false;
    }
}

4. 创建一个JwtAuthenticationFilter类，拦截请求并验证JWT：

public class JwtAuthenticationFilter extends OncePerRequestFilter {

    @Autowired
    private JwtTokenProvider jwtTokenProvider;

    @Autowired
    private CustomUserDetailsService customUserDetailsService;

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
        try {
            String jwt = getJwtFromRequest(request);

            if (StringUtils.hasText(jwt) && jwtTokenProvider.validateToken(jwt)) {
                Long userId = jwtTokenProvider.getUserIdFromToken(jwt);
                UserDetails userDetails = customUserDetailsService.loadUserById(userId);

                UsernamePasswordAuthenticationToken authentication = new UsernamePasswordAuthenticationToken(userDetails, null, userDetails.getAuthorities());
                authentication.setDetails(new WebAuthenticationDetailsSource().buildDetails(request));

                SecurityContextHolder.getContext().setAuthentication(authentication);
            }
        } catch (Exception ex) {
            logger.error("Could not set user authentication in security context", ex);
        }

        filterChain.doFilter(request, response);
    }

    private String getJwtFromRequest(HttpServletRequest request) {
        String bearerToken = request.getHeader("Authorization");
        if (StringUtils.hasText(bearerToken) && bearerToken.startsWith("Bearer ")) {
            return bearerToken.substring(7, bearerToken.length());
        }
        return null;
    }
}

5. 创建一个JwtAuthenticationEntryPoint类，处理未授权的请求：

@Component
public class JwtAuthenticationEntryPoint implements AuthenticationEntryPoint {

    @Override
    public void commence(HttpServletRequest request, HttpServletResponse response, AuthenticationException authException) throws IOException, ServletException {
        response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Unauthorized");
    }
}

6. 创建一个UserPrincipal类，实现Spring Security的UserDetails接口：

public class UserPrincipal implements UserDetails {

    private Long id;
    private String username;
    private String email;
    private String password;
    private Collection<? extends GrantedAuthority> authorities;

    public UserPrincipal(Long id, String username, String email, String password, Collection<? extends GrantedAuthority> authorities) {
        this.id = id;
        this.username = username;
        this.email = email;
        this.password = password;
        this.authorities = authorities;
    }

    public Long getId() {
        return id;
    }

    public String getEmail() {
        return email;
    }

    @Override
    public Collection<? extends GrantedAuthority> getAuthorities() {
        return authorities;
    }

    @Override
    public String getPassword() {
        return password;
    }

    @Override
    public String getUsername() {
        return username;
    }

    @Override
    public boolean isAccountNonExpired() {
        return true;
    }

    @Override
    public boolean isAccountNonLocked() {
        return true;
    }

    @Override
    public boolean isCredentialsNonExpired() {
        return true;
    }

    @Override
    public boolean isEnabled() {
        return true;
    }
}

7. 创建一个CustomUserDetailsService类，实现Spring Security的UserDetailsService接口：

@Service
public class CustomUserDetailsService implements UserDetailsService {

    @Autowired
    private UserRepository userRepository;

    @Override
    @Transactional
    public UserDetails loadUserByUsername(String usernameOrEmail) throws UsernameNotFoundException {
        User user = userRepository.findByUsernameOrEmail(usernameOrEmail, usernameOrEmail)
                .orElseThrow(() ->
                        new UsernameNotFoundException("User not found with username or email : " + usernameOrEmail)
                );

        return UserPrincipal.create(user);
    }

    @Transactional
    public UserDetails loadUserById(Long id) {
        User user = userRepository.findById(id)
                .orElseThrow(() ->
                        new ResourceNotFoundException("User", "id", id)
                );

        return UserPrincipal.create(user);
    }
}

以上就是Spring Security结合JWT实现单点登录的代码流程，可以根据具体的需求进行相应的修改和调整。