前言

在 Spring Security 中，默认的登陆方式是以表单形式进行提交参数的。可以参考前面的几篇文章，但是在前后端分离的项目，前后端都是以 JSON 形式交互的。一般不会使用表单形式提交参数。所以，在 Spring Security 中如果要使用 JSON 格式登录，需要自己来实现。那本文介绍两种方式使用 JSON 登录。

• 方式一：重写 UsernamePasswordAuthenticationFilter 过滤器
• 方式二：自定义登录接口

方式一

通过前面几篇文章的分析，我们已经知道了登录参数的提取在 UsernamePasswordAuthenticationFilter 过滤器中提取的，因此我们只需要模仿UsernamePasswordAuthenticationFilter过滤器重写一个过滤器，替代原有的UsernamePasswordAuthenticationFilter过滤器即可。

UsernamePasswordAuthenticationFilter 的源代码如下：

重写的逻辑如下：

public class LoginFilter extends UsernamePasswordAuthenticationFilter {@Overridepublic Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException {// 需要是 POST 请求if (!request.getMethod().equals("POST")) {throw new AuthenticationServiceException("Authentication method not supported: " + request.getMethod());}HttpSession session = request.getSession();// 获得 session 中的 验证码值String sessionVerifyCode = (String) session.getAttribute("verify_code");// 判断请求格式是否是 JSONif (request.getContentType().equals(MediaType.APPLICATION_JSON_VALUE) || request.getContentType().equals(MediaType.APPLICATION_JSON_UTF8_VALUE)) {Map loginData = new HashMap<>();try {loginData = new ObjectMapper().readValue(request.getInputStream(), Map.class);} catch (IOException e) {}finally {String code = loginData.get("code");checkVerifyCode(sessionVerifyCode, code);}String username = loginData.get(getUsernameParameter());String password = loginData.get(getPasswordParameter());if(StringUtils.isEmpty(username)){throw new AuthenticationServiceException("用户名不能为空");}if(StringUtils.isEmpty(password)){throw new AuthenticationServiceException("密码不能为空");}UsernamePasswordAuthenticationToken authRequest = new UsernamePasswordAuthenticationToken(username, password);setDetails(request, authRequest);return this.getAuthenticationManager().authenticate(authRequest);}else {checkVerifyCode(sessionVerifyCode, request.getParameter("code"));return super.attemptAuthentication(request, response);}}private void checkVerifyCode(String sessionVerifyCode, String code) {if (StringUtils.isEmpty(code)){throw new AuthenticationServiceException("验证码不能为空!");}if(StringUtils.isEmpty(sessionVerifyCode)){throw new AuthenticationServiceException("请重新申请验证码!");}if (!sessionVerifyCode.equalsIgnoreCase(code)) {throw new AuthenticationServiceException("验证码错误!");}}
}
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上述代码逻辑如下：

• 1、当前登录请求是否是 POST 请求，如果不是，则抛出异常。
• 2、判断请求格式是否是 JSON，如果是则走我们自定义的逻辑，如果不是则调用 super.attemptAuthentication 方法，进入父类原本的处理逻辑中；当然也可以抛出异常。
• 3、如果是 JSON 请求格式的数据，通过 ObjectMapper 读取 request 中的 I/O 流，将 JSON 映射到Map 上。
• 4、从 Map 中取出 code key的值，判断验证码是否正确，如果验证码有错，则直接抛出异常。如果对验证码相关逻辑感到疑惑，请前往：【Spring Security 在登录时如何添加图形验证码验证】
• 5、根据用户名、密码构建 UsernamePasswordAuthenticationToken 对象，然后调用官方的方法进行验证，验证用户名、密码是否真实有效。

接下来就是将我们自定义的 LoginFilter 过滤器代替默认的 UsernamePasswordAuthenticationFilter。

import cn.cxyxj.study05.filter.config.MyAuthenticationEntryPoint;
import cn.cxyxj.study05.filter.config.MyAuthenticationFailureHandler;
import cn.cxyxj.study05.filter.config.MyAuthenticationSuccessHandler;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.crypto.password.NoOpPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.security.provisioning.InMemoryUserDetailsManager;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {@BeanPasswordEncoder passwordEncoder() {return NoOpPasswordEncoder.getInstance();}@Bean@Overrideprotected UserDetailsService userDetailsService() {InMemoryUserDetailsManager manager = new InMemoryUserDetailsManager();manager.createUser(User.withUsername("cxyxj").password("123").roles("admin").build());manager.createUser(User.withUsername("security").password("security").roles("user").build());return manager;}@Override@Beanpublic AuthenticationManager authenticationManagerBean()throws Exception {return super.authenticationManagerBean();}@Overrideprotected void configure(HttpSecurity http) throws Exception {// 用自定义的 LoginFilter 实例代替 UsernamePasswordAuthenticationFilterhttp.addFilterBefore(loginFilter(), UsernamePasswordAuthenticationFilter.class);http.authorizeRequests()  //开启配置// 验证码、登录接口放行.antMatchers("/verify-code","/auth/login").permitAll().anyRequest() //其他请求.authenticated().and()//验证   表示其他请求需要登录才能访问.csrf().disable();  // 禁用 csrf 保护http.exceptionHandling().authenticationEntryPoint(new MyAuthenticationEntryPoint());}@BeanLoginFilter loginFilter() throws Exception {LoginFilter loginFilter = new LoginFilter();loginFilter.setFilterProcessesUrl("/auth/login");loginFilter.setUsernameParameter("account");loginFilter.setPasswordParameter("pwd");loginFilter.setAuthenticationManager(authenticationManagerBean());loginFilter.setAuthenticationSuccessHandler(new MyAuthenticationSuccessHandler());loginFilter.setAuthenticationFailureHandler(new MyAuthenticationFailureHandler());return loginFilter;}}
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当我们替换了 UsernamePasswordAuthenticationFilter 之后，原本在 SecurityConfig#configure 方法中关于 form 表单的配置就会失效，那些失效的属性，都可以在配置 LoginFilter 实例的时候配置；还需要记得配置AuthenticationManager，否则启动时会报错。

• MyAuthenticationFailureHandler

import org.springframework.security.authentication.BadCredentialsException;
import org.springframework.security.authentication.LockedException;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.authentication.AuthenticationFailureHandler;import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
/*** 登录失败回调*/
public class MyAuthenticationFailureHandler implements AuthenticationFailureHandler {@Overridepublic void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response, AuthenticationException e) throws IOException, ServletException {response.setContentType("application/json;charset=utf-8");PrintWriter out = response.getWriter();String msg = "";if (e instanceof LockedException) {msg = "账户被锁定，请联系管理员!";}else if (e instanceof BadCredentialsException) {msg = "用户名或者密码输入错误，请重新输入!";}out.write(e.getMessage());out.flush();out.close();}
}
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• MyAuthenticationSuccessHandler

import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.security.core.Authentication;
import org.springframework.security.web.authentication.AuthenticationSuccessHandler;import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;/*** 登录成功回调*/
public class MyAuthenticationSuccessHandler implements AuthenticationSuccessHandler {@Overridepublic void onAuthenticationSuccess(HttpServletRequest request, HttpServletResponse response, Authentication authentication) throws IOException, ServletException {Object principal = authentication.getPrincipal();response.setContentType("application/json;charset=utf-8");PrintWriter out = response.getWriter();out.write(new ObjectMapper().writeValueAsString(principal));out.flush();out.close();}}
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• MyAuthenticationEntryPoint

import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.AuthenticationEntryPoint;import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
/*** 未登录但访问需要登录的接口异常回调*/
public class MyAuthenticationEntryPoint implements AuthenticationEntryPoint {@Overridepublic void commence(HttpServletRequest request, HttpServletResponse response, AuthenticationException e) throws IOException, ServletException {response.setContentType("application/json;charset=utf-8");PrintWriter out = response.getWriter();out.write("您未登录，请先登录！");out.flush();out.close();}
}
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测试

提供一个业务接口，该接口需要登录才能访问

@GetMapping("/hello")
public String hello(){return "登录成功访问业务接口";
}
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OK，启动项目，先访问一下 hello 接口。

接下来先调用验证码接口，然后再访问登录接口，如下：

再次访问业务接口!

方式二

@PostMapping("/doLogin")
public Object login(@RequestBody LoginReq req) {String account = req.getAccount();String pwd = req.getPwd();String code = req.getCode();UsernamePasswordAuthenticationToken authenticationToken =new UsernamePasswordAuthenticationToken(account, pwd);Authentication authentication = authenticationManager.authenticate(authenticationToken);SecurityContextHolder.getContext().setAuthentication(authentication);return authentication.getPrincipal();
}public class LoginReq {private String account;private String pwd;private String code;
}
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方式二就是在我们自己的 Controller 层中，编写一个登录接口，接收用户名、密码、验证码参数。根据用户名、密码构建 UsernamePasswordAuthenticationToken 对象，然后调用官方的方法进行验证，验证用户名、密码是否真实有效；最后将认证对象放入到 Security 的上下文中。就三行代码就实现了简单的登录功能。

import cn.cxyxj.study05.custom.config.MyAuthenticationEntryPoint;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.crypto.password.NoOpPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.security.provisioning.InMemoryUserDetailsManager;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {@BeanPasswordEncoder passwordEncoder() {return NoOpPasswordEncoder.getInstance();}@Bean@Overrideprotected UserDetailsService userDetailsService() {InMemoryUserDetailsManager manager = new InMemoryUserDetailsManager();manager.createUser(User.withUsername("cxyxj").password("123").roles("admin").build());manager.createUser(User.withUsername("security").password("security").roles("user").build());return manager;}@Override@Beanpublic AuthenticationManager authenticationManagerBean()throws Exception {return super.authenticationManagerBean();}@Overrideprotected void configure(HttpSecurity http) throws Exception {http.authorizeRequests()  //开启配置// 验证码、登录接口放行.antMatchers("/verify-code","/doLogin").permitAll().anyRequest() //其他请求.authenticated().and()//验证   表示其他请求需要登录才能访问.csrf().disable();  // 禁用 csrf 保护http.exceptionHandling().authenticationEntryPoint(new MyAuthenticationEntryPoint());}
}
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简简单单的配置一下内存用户，接口放行。

• MyAuthenticationEntryPoint

import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.AuthenticationEntryPoint;import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
/*** 未登录但访问需要登录的接口异常回调*/
public class MyAuthenticationEntryPoint implements AuthenticationEntryPoint {@Overridepublic void commence(HttpServletRequest request, HttpServletResponse response, AuthenticationException e) throws IOException, ServletException {response.setContentType("application/json;charset=utf-8");PrintWriter out = response.getWriter();out.write("您未登录，请先登录！");out.flush();out.close();}
}
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测试

还是先来访问一下业务接口，如下：

再访问登录接口，如下：

登录成功之后，访问业务接口，如下：

• 自定义官方过滤器方式，要重写各种接口，比如失败回调、登录成功回调，因为官方已经将这些逻辑单独抽离出来了。需要对认证流程有一定的了解，不然你都不知道为什么需要实现这个接口。
• 自定义接口方式，只要写好那几行代码，你就可以在后面自定义自己的逻辑，比如：密码输入错误次数限制，这种方式代码编写起来更流畅一点，不需要这个类写一点代码，那个类写一点代码。

两者之间没有哪种方式更好，看公司、个人的开发习惯吧！但自定义接口方法应该用的会比较多一点，笔者公司用的就是该方式。