spring-boot+mybatis+restful api+jwt登陆（2）

前文回顾spring-boot+mybatis+restful api+jwt登陆（1）

用spring-boot开发RESTful API非常的方便，在生产环境中，对发布的API增加授权保护是非常必要的。现在我们来看如何利用JWT技术为API增加授权保护，保证只有获得授权的用户才能够访问API。

1. 引入security和jwt依赖

前文已经引入了这两个包，这里再看一下这两个是如何引入的

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.7.0</version>
        </dependency>

2. 增加注册功能

利用前文引入的mybatis自动生成代码的插件，生成model和mapper

User类，省略setter和getter方法

public class User {
    private String id;

    private String username;

    private String password;

    private String email;

    private String mobile;

    private String loginIp;

    private Date loginTime;

    private Byte isAviliable;

    private Integer type;

    private String avatar;
}

UserMapper

public interface UserMapper {
    int deleteByPrimaryKey(String id);

    int insert(User record);

    int insertSelective(User record);

    User selectByPrimaryKey(String id);

    int updateByPrimaryKeySelective(User record);

    int updateByPrimaryKey(User record);

    User findByUsername(String username);
}

插件还会生成对应的mapper.xml，具体代码不再贴出了

创建UserService类，加入signup方法

@Service
public class UserService {
    @Autowired
    UserMapper userMapper;
    @Autowired
    BCryptPasswordEncoder bCryptPasswordEncoder;

    public User signup(User user) {
        user.setId(UUID.randomUUID().toString());
        user.setPassword(bCryptPasswordEncoder.encode(user.getPassword()));
        userMapper.insertSelective(user);
        return user;
    }
}

加入控制层代码

@RestController
@RequestMapping("api/user")
public class UserController {

    @Autowired
    UserService userService;

    @PostMapping(value = "/signup")
    public User signup(@RequestBody User user) {
        user = userService.signup(user);
        return user;
    }
}

密码采用了BCryptPasswordEncoder进行加密，我们在启动类中增加BCryptPasswordEncoder实例的定义。

@SpringBootApplication
@MapperScan("com.itcuc.qaserver.mapper")
@ServletComponentScan
public class QaserverApplication {

    public static void main(String[] args) {
        SpringApplication.run(QaserverApplication.class, args);
    }

    @Bean
    public BCryptPasswordEncoder bCryptPasswordEncoder() {
        return new BCryptPasswordEncoder();
    }
}

3. 增加jwt认证功能

用户填入用户名密码后，与数据库里存储的用户信息进行比对，如果通>过，则认证成功。传统的方法是在认证通过后，创建sesstion，并给客户端返回cookie。现在我们采用JWT来处理用户名密码的认证。区别在于，认证通过后，服务器生成一个token，将token返回给客户端，客户端以后的所有请求都需要在http头中指定该token。服务器接收的请求后，会对token的合法性进行验证。验证的内容包括：

内容是一个正确的JWT格式

检查签名

检查claims

检查权限

处理登录

创建一个类JWTLoginFilter，核心功能是在验证用户名密码正确后，生成一个token，并将token返回给客户端：

public class JWTLoginFilter extends UsernamePasswordAuthenticationFilter {

    private AuthenticationManager authenticationManager;

    public JWTLoginFilter(AuthenticationManager authenticationManager) {
        this.authenticationManager = authenticationManager;
    }

    // 接收并解析用户凭证
    @Override
    public Authentication attemptAuthentication(HttpServletRequest req,
                                                HttpServletResponse res) throws AuthenticationException {
        try {
            User user = new ObjectMapper()
                    .readValue(req.getInputStream(), User.class);

            return authenticationManager.authenticate(
                    new UsernamePasswordAuthenticationToken(
                            user.getUsername(),
                            user.getPassword(),
                            new ArrayList<>())
            );
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    // 用户成功登录后，这个方法会被调用，我们在这个方法里生成token
    @Override
    protected void successfulAuthentication(HttpServletRequest req,
                                            HttpServletResponse res,
                                            FilterChain chain,
                                            Authentication auth) throws IOException, ServletException {

        String token = Jwts.builder()
                .setSubject(((org.springframework.security.core.userdetails.User) auth.getPrincipal()).getUsername())
                .setExpiration(new Date(System.currentTimeMillis() + 60 * 60 * 24 * 1000))
                .signWith(SignatureAlgorithm.HS512, "MyJwtSecret")
                .compact();
        res.addHeader("Authorization", "Bearer " + token);
    }

}

该类继承自UsernamePasswordAuthenticationFilter，重写了其中的2个方法：

attemptAuthentication ：接收并解析用户凭证。

successfulAuthentication ：用户成功登录后，这个方法会被调用，我们在这个方法里生成token。

授权验证

用户一旦登录成功后，会拿到token，后续的请求都会带着这个token，服务端会验证token的合法性。

创建JWTAuthenticationFilter类，我们在这个类中实现token的校验功能。

public class JWTAuthenticationFilter extends BasicAuthenticationFilter {

    public JWTAuthenticationFilter(AuthenticationManager authenticationManager) {
        super(authenticationManager);
    }

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException {
        String header = request.getHeader("Authorization");

        if (header == null || !header.startsWith("Bearer ")) {
            chain.doFilter(request, response);
            return;
        }

        UsernamePasswordAuthenticationToken authentication = getAuthentication(request);

        SecurityContextHolder.getContext().setAuthentication(authentication);
        chain.doFilter(request, response);

    }

    private UsernamePasswordAuthenticationToken getAuthentication(HttpServletRequest request) {
        String token = request.getHeader("Authorization");
        if (token != null) {
            // parse the token.
            String user = Jwts.parser()
                    .setSigningKey("MyJwtSecret")
                    .parseClaimsJws(token.replace("Bearer ", ""))
                    .getBody()
                    .getSubject();

            if (user != null) {
                return new UsernamePasswordAuthenticationToken(user, null, new ArrayList<>());
            }
            return null;
        }
        return null;
    }

}

该类继承自BasicAuthenticationFilter，在doFilterInternal方法中，从http头的Authorization 项读取token数据，然后用Jwts包提供的方法校验token的合法性。如果校验通过，就认为这是一个取得授权的合法请求。

SpringSecurity配置

通过SpringSecurity的配置，将上面的方法组合在一起。

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    private UserDetailsService userDetailsService;

    private BCryptPasswordEncoder bCryptPasswordEncoder;

    public WebSecurityConfig(UserDetailsService userDetailsService, BCryptPasswordEncoder bCryptPasswordEncoder) {
        this.userDetailsService = userDetailsService;
        this.bCryptPasswordEncoder = bCryptPasswordEncoder;
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.cors().and().csrf().disable().authorizeRequests()
                .antMatchers(HttpMethod.POST, "/api/user/signup").permitAll()
                .anyRequest().authenticated()
                .and()
                .addFilter(new JWTLoginFilter(authenticationManager()))
                .addFilter(new JWTAuthenticationFilter(authenticationManager()));
    }

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

}

这是标准的SpringSecurity配置内容，就不在详细说明。注意其中的

.addFilter(new JWTLoginFilter(authenticationManager()))
.addFilter(new JwtAuthenticationFilter(authenticationManager()))

这两行，将我们定义的JWT方法加入SpringSecurity的处理流程中。

(以上内容引用自https://blog.csdn.net/sxdtzhaoxinguo/article/details/77965226)

这里需要实现UserDetailsService接口

@Service
public class UserDetailsServiceImpl implements UserDetailsService {

    private UserMapper userMapper;

    /**
     * 通过构造器注入UserRepository
     * @param userMapper
     */
    public UserDetailsServiceImpl(UserMapper userMapper) {
        this.userMapper = userMapper;
    }

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        User user = userMapper.findByUsername(username);
        if(user == null){
            throw new UsernameNotFoundException(username);
        }
        return new org.springframework.security.core.userdetails.User(user.getUsername(), user.getPassword(), emptyList());
    }

}

这时再请求hello接口，会返回403错误