Spring Security 登录使用 JSON 格式数据

在使用 SpringSecurity 中，大伙都知道默认的登录数据是通过 key/value 的形式来传递的，默认情况下不支持 JSON格式的登录数据，如果有这种需求，就需要自己来解决，本文主要和小伙伴来聊聊这个话题。

基本登录方案

在说如何使用 JSON 登录之前，我们还是先来看看基本的登录吧，本文为了简单，SpringSecurity 在使用中就不连接数据库了，直接在内存中配置用户名和密码，具体操作步骤如下：

创建 Spring Boot 工程

首先创建 SpringBoot 工程，添加 SpringSecurity 依赖，如下：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

添加 Security 配置

创建 SecurityConfig，完成 SpringSecurity 的配置，如下：

@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Bean
    PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }
    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.inMemoryAuthentication().withUser("zhangsan").password("$2a$10$2O4EwLrrFPEboTfDOtC0F.RpUMk.3q3KvBHRx7XXKUMLBGjOOBs8q").roles("user");
    }

    @Override
    public void configure(WebSecurity web) throws Exception {
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
                .anyRequest().authenticated()
                .and()
                .formLogin()
                .loginProcessingUrl("/doLogin")
                .successHandler(new AuthenticationSuccessHandler() {
                    @Override
                    public void onAuthenticationSuccess(HttpServletRequest req, HttpServletResponse resp, Authentication authentication) throws IOException, ServletException {
                        RespBean ok = RespBean.ok("登录成功！",authentication.getPrincipal());
                        resp.setContentType("application/json;charset=utf-8");
                        PrintWriter out = resp.getWriter();
                        out.write(new ObjectMapper().writeValueAsString(ok));
                        out.flush();
                        out.close();
                    }
                })
                .failureHandler(new AuthenticationFailureHandler() {
                    @Override
                    public void onAuthenticationFailure(HttpServletRequest req, HttpServletResponse resp, AuthenticationException e) throws IOException, ServletException {
                        RespBean error = RespBean.error("登录失败");
                        resp.setContentType("application/json;charset=utf-8");
                        PrintWriter out = resp.getWriter();
                        out.write(new ObjectMapper().writeValueAsString(error));
                        out.flush();
                        out.close();
                    }
                })
                .loginPage("/login")
                .permitAll()
                .and()
                .logout()
                .logoutUrl("/logout")
                .logoutSuccessHandler(new LogoutSuccessHandler() {
                    @Override
                    public void onLogoutSuccess(HttpServletRequest req, HttpServletResponse resp, Authentication authentication) throws IOException, ServletException {
                        RespBean ok = RespBean.ok("注销成功！");
                        resp.setContentType("application/json;charset=utf-8");
                        PrintWriter out = resp.getWriter();
                        out.write(new ObjectMapper().writeValueAsString(ok));
                        out.flush();
                        out.close();
                    }
                })
                .permitAll()
                .and()
                .csrf()
                .disable()
                .exceptionHandling()
                .accessDeniedHandler(new AccessDeniedHandler() {
                    @Override
                    public void handle(HttpServletRequest req, HttpServletResponse resp, AccessDeniedException e) throws IOException, ServletException {
                        RespBean error = RespBean.error("权限不足，访问失败");
                        resp.setStatus(403);
                        resp.setContentType("application/json;charset=utf-8");
                        PrintWriter out = resp.getWriter();
                        out.write(new ObjectMapper().writeValueAsString(error));
                        out.flush();
                        out.close();
                    }
                });

    }
}

这里的配置虽然有点长，但是很基础，配置含义也比较清晰，首先提供 BCryptPasswordEncoder 作为 PasswordEncoder ，可以实现对密码的自动加密加盐，非常方便，然后提供了一个名为 zhangsan 的用户，密码是 123 ，角色是 user ，最后配置登录逻辑，所有的请求都需要登录后才能访问，登录接口是 /doLogin ，用户名的 key 是 username ，密码的 key 是 password ，同时配置登录成功、登录失败以及注销成功、权限不足时都给用户返回JSON提示，另外，这里虽然配置了登录页面为 /login ，实际上这不是一个页面，而是一段 JSON ，在 LoginController 中提供该接口，如下：

@RestController
@ResponseBody
public class LoginController {
    @GetMapping("/login")
    public RespBean login() {
        return RespBean.error("尚未登录，请登录");
    }
    @GetMapping("/hello")
    public String hello() {
        return "hello";
    }
}

这里 /login 只是一个 JSON 提示，而不是页面， /hello 则是一个测试接口。

OK，做完上述步骤就可以开始测试了，运行SpringBoot项目，访问 /hello 接口，结果如下：

此时先调用登录接口进行登录，如下：

登录成功后，再去访问 /hello 接口就可以成功访问了。

使用JSON登录

上面演示的是一种原始的登录方案，如果想将用户名密码通过 JSON 的方式进行传递，则需要自定义相关过滤器，通过分析源码我们发现，默认的用户名密码提取在 UsernamePasswordAuthenticationFilter 过滤器中，部分源码如下：

public class UsernamePasswordAuthenticationFilter extends
		AbstractAuthenticationProcessingFilter {
	public static final String SPRING_SECURITY_FORM_USERNAME_KEY = "username";
	public static final String SPRING_SECURITY_FORM_PASSWORD_KEY = "password";

	private String usernameParameter = SPRING_SECURITY_FORM_USERNAME_KEY;
	private String passwordParameter = SPRING_SECURITY_FORM_PASSWORD_KEY;
	private boolean postOnly = true;
	public UsernamePasswordAuthenticationFilter() {
		super(new AntPathRequestMatcher("/login", "POST"));
	}

	public Authentication attemptAuthentication(HttpServletRequest request,
			HttpServletResponse response) throws AuthenticationException {
		if (postOnly && !request.getMethod().equals("POST")) {
			throw new AuthenticationServiceException(
					"Authentication method not supported: " + request.getMethod());
		}

		String username = obtainUsername(request);
		String password = obtainPassword(request);

		if (username == null) {
			username = "";
		}

		if (password == null) {
			password = "";
		}

		username = username.trim();

		UsernamePasswordAuthenticationToken authRequest = new UsernamePasswordAuthenticationToken(
				username, password);

		// Allow subclasses to set the "details" property
		setDetails(request, authRequest);

		return this.getAuthenticationManager().authenticate(authRequest);
	}

	protected String obtainPassword(HttpServletRequest request) {
		return request.getParameter(passwordParameter);
	}

	protected String obtainUsername(HttpServletRequest request) {
		return request.getParameter(usernameParameter);
	}
    //...
    //...
}

从这里可以看到，默认的用户名/密码提取就是通过 request 中的 getParameter 来提取的，如果想使用 JSON 传递用户名密码，只需要将这个过滤器替换掉即可，自定义过滤器如下：

public class CustomAuthenticationFilter extends UsernamePasswordAuthenticationFilter {
    @Override
    public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException {
        if (request.getContentType().equals(MediaType.APPLICATION_JSON_UTF8_VALUE)
                || request.getContentType().equals(MediaType.APPLICATION_JSON_VALUE)) {
            ObjectMapper mapper = new ObjectMapper();
            UsernamePasswordAuthenticationToken authRequest = null;
            try (InputStream is = request.getInputStream()) {
                Map<String,String> authenticationBean = mapper.readValue(is, Map.class);
                authRequest = new UsernamePasswordAuthenticationToken(
                        authenticationBean.get("username"), authenticationBean.get("password"));
            } catch (IOException e) {
                e.printStackTrace();
                authRequest = new UsernamePasswordAuthenticationToken(
                        "", "");
            } finally {
                setDetails(request, authRequest);
                return this.getAuthenticationManager().authenticate(authRequest);
            }
        }
        else {
            return super.attemptAuthentication(request, response);
        }
    }
}

这里只是将用户名/密码的获取方案重新修正下，改为了从 JSON 中获取用户名密码，然后在 SecurityConfig 中作出如下修改：

@Override
protected void configure(HttpSecurity http) throws Exception {
    http.authorizeRequests().anyRequest().authenticated()
            .and()
            .formLogin()
            .and().csrf().disable();
    http.addFilterAt(customAuthenticationFilter(), UsernamePasswordAuthenticationFilter.class);
}
@Bean
CustomAuthenticationFilter customAuthenticationFilter() throws Exception {
    CustomAuthenticationFilter filter = new CustomAuthenticationFilter();
    filter.setAuthenticationSuccessHandler(new AuthenticationSuccessHandler() {
        @Override
        public void onAuthenticationSuccess(HttpServletRequest req, HttpServletResponse resp, Authentication authentication) throws IOException, ServletException {
            resp.setContentType("application/json;charset=utf-8");
            PrintWriter out = resp.getWriter();
            RespBean respBean = RespBean.ok("登录成功!");
            out.write(new ObjectMapper().writeValueAsString(respBean));
            out.flush();
            out.close();
        }
    });
    filter.setAuthenticationFailureHandler(new AuthenticationFailureHandler() {
        @Override
        public void onAuthenticationFailure(HttpServletRequest req, HttpServletResponse resp, AuthenticationException e) throws IOException, ServletException {
            resp.setContentType("application/json;charset=utf-8");
            PrintWriter out = resp.getWriter();
            RespBean respBean = RespBean.error("登录失败!");
            out.write(new ObjectMapper().writeValueAsString(respBean));
            out.flush();
            out.close();
        }
    });
    filter.setAuthenticationManager(authenticationManagerBean());
    return filter;
}

将自定义的 CustomAuthenticationFilter 类加入进来即可，接下来就可以使用 JSON 进行登录了，如下：

好了，本文就先介绍到这里，有问题欢迎留言讨论。

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