一文搞懂Spring Security异常处理机制

resp.setContentType("application/JSON;charset=utf-8");
PrintWriter out = resp.getWriter();
RespBean respBean = RespBean.error(e.getMessage());
if (e instanceof LockedException) {
    respBean.setMsg("账户被锁定，请联系管理员!");
} else if (e instanceof CredentialsExpiredException) {
    respBean.setMsg("密码过期，请联系管理员!");
} else if (e instanceof AccountExpiredException) {
    respBean.setMsg("账户过期，请联系管理员!");
} else if (e instanceof DisabledException) {
    respBean.setMsg("账户被禁用，请联系管理员!");
} else if (e instanceof BadCredentialsException) {
    respBean.setMsg("用户名或者密码输入错误，请重新输入!");
}
out.write(new ObjectMapper().writeValueAsString(respBean));
out.flush();
out.close();

protected final HttpSecurity getHttp() throws Exception {
	if (http != null) {
		return http;
	}
	AuthenticationEventPublisher eventPublisher = getAuthenticationEventPublisher();
	localConfigureAuthenticationBldr.authenticationEventPublisher(eventPublisher);
	AuthenticationManager authenticationManager = authenticationManager();
	authenticationBuilder.parentAuthenticationManager(authenticationManager);
	Map<Class<?>, Object> sharedObjects = createSharedObjects();
	http = new HttpSecurity(objectPostProcessor, authenticationBuilder,
			sharedObjects);
	if (!disableDefaults) {
		http
			.csrf().and()
			.addFilter(new WebAsyncManagerIntegrationFilter())
			.exceptionHandling().and()
			.headers().and()
			.sessionManagement().and()
			.securityContext().and()
			.requestCache().and()
			.anonymous().and()
			.servletapi().and()
			.apply(new DefaultLoginPageConfigurer<>()).and()
			.loGout();
		ClassLoader classLoader = this.context.getClassLoader();
		List<AbstractHttpConfigurer> defaultHttpConfigurers =
				SpringFactoriesLoader.loadFactories(AbstractHttpConfigurer.class, classLoader);
		for (AbstractHttpConfigurer configurer : defaultHttpConfigurers) {
			http.apply(configurer);
		}
	}
	configure(http);
	return http;
}

@Override
public void configure(H http) {
	AuthenticationEntryPoint entryPoint = getAuthenticationEntryPoint(http);
	ExceptionTranslationFilter exceptionTranslationFilter = new ExceptionTranslationFilter(
			entryPoint, getRequestCache(http));
	AccessDeniedHandler deniedHandler = getAccessDeniedHandler(http);
	exceptionTranslationFilter.setAccessDeniedHandler(deniedHandler);
	exceptionTranslationFilter = postProcess(exceptionTranslationFilter);
	http.addFilter(exceptionTranslationFilter);
}

public class ExceptionTranslationFilter extends GenericFilterBean {
	public ExceptionTranslationFilter(AuthenticationEntryPoint authenticationEntryPoint,
			RequestCache requestCache) {
		this.authenticationEntryPoint = authenticationEntryPoint;
		this.requestCache = requestCache;
	}
	public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
			throws IOException, ServletException {
		HttpServletRequest request = (HttpServletRequest) req;
		HttpServletResponse response = (HttpServletResponse) res;
		try {
			chain.doFilter(request, response);
		}
		catch (IOException ex) {
			throw ex;
		}
		catch (Exception ex) {
			Throwable[] causeChain = throwableAnalyzer.determineCauseChain(ex);
			RuntimeException ase = (AuthenticationException) throwableAnalyzer
					.getFirstThrowableOfType(AuthenticationException.class, causeChain);
			if (ase == null) {
				ase = (AccessDeniedException) throwableAnalyzer.getFirstThrowableOfType(
						AccessDeniedException.class, causeChain);
			}
			if (ase != null) {
				if (response.isCommitted()) {
					throw new ServletException("Unable to handle the Spring Security Exception because the response is already committed.", ex);
				}
				handleSpringSecurityException(request, response, chain, ase);
			}
			else {
				if (ex instanceof ServletException) {
					throw (ServletException) ex;
				}
				else if (ex instanceof RuntimeException) {
					throw (RuntimeException) ex;
				}
				throw new RuntimeException(ex);
			}
		}
	}
	private void handleSpringSecurityException(HttpServletRequest request,
			HttpServletResponse response, FilterChain chain, RuntimeException exception)
			throws IOException, ServletException {
		if (exception instanceof AuthenticationException) {
			sendStartAuthentication(request, response, chain,
					(AuthenticationException) exception);
		}
		else if (exception instanceof AccessDeniedException) {
			Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
			if (authenticationTrustResolver.isAnonymous(authentication) || authenticationTrustResolver.isRememberMe(authentication)) {
				sendStartAuthentication(
						request,
						response,
						chain,
						new InsufficientAuthenticationException(
							messages.getMessage(
								"ExceptionTranslationFilter.insufficientAuthentication",
								"Full authentication is required to access this resource")));
			}
			else {
				accessDeniedHandler.handle(request, response,
						(AccessDeniedException) exception);
			}
		}
	}
	protected void sendStartAuthentication(HttpServletRequest request,
			HttpServletResponse response, FilterChain chain,
			AuthenticationException reason) throws ServletException, IOException {
		SecurityContextHolder.getContext().setAuthentication(null);
		requestCache.saveRequest(request, response);
		logger.debug("Calling Authentication entry point.");
		authenticationEntryPoint.commence(request, response, reason);
	}
}

public void commence(HttpServletRequest request, HttpServletResponse response,
		AuthenticationException authException) throws IOException, ServletException {
	String redirectUrl = null;
	if (useForward) {
		if (forceHttps && "http".equals(request.getScheme())) {
			redirectUrl = buildHttpsRedirectUrlForRequest(request);
		}
		if (redirectUrl == null) {
			String loginFORM = determineUrlToUseForThisRequest(request, response,
					authException);
			RequestDispatcher dispatcher = request.getRequestDispatcher(loginForm);
			dispatcher.forward(request, response);
			return;
		}
	}
	else {
		redirectUrl = buildRedirectUrlToLoginPage(request, response, authException);
	}
	redirectStrategy.sendRedirect(request, response, redirectUrl);
}

public void handle(HttpServletRequest request, HttpServletResponse response,
		AccessDeniedException accessDeniedException) throws IOException,
		ServletException {
	if (!response.isCommitted()) {
		if (errorPage != null) {
			request.setAttribute(WebAttributes.ACCESS_DENIED_403,
					accessDeniedException);
			response.setStatus(HttpStatus.FORBIDDEN.value());
			RequestDispatcher dispatcher = request.getRequestDispatcher(errorPage);
			dispatcher.forward(request, response);
		}
		else {
			response.sendError(HttpStatus.FORBIDDEN.value(),
				HttpStatus.FORBIDDEN.getReasonPhrase());
		}
	}
}

@Component
public class MyAuthenticationEntryPoint implements AuthenticationEntryPoint {
    @Override
    public void commence(HttpServletRequest request, HttpServletResponse response, AuthenticationException authException) throws IOException, ServletException {
        response.getWriter().write("login failed:" + authException.getMessage());
    }
}
@Component
public class MyAccessDeniedHandler implements AccessDeniedHandler {
    @Override
    public void handle(HttpServletRequest request, HttpServletResponse response, AccessDeniedException accessDeniedException) throws IOException, ServletException {
        response.setStatus(403);
        response.getWriter().write("Forbidden:" + accessDeniedException.getMessage());
    }
}

@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
                ...
                ...
                .and()
                .exceptionHandling()
                .authenticationEntryPoint(myAuthenticationEntryPoint)
                .accessDeniedHandler(myAccessDeniedHandler)
                .and()
                ...
                ...
    }
}