特别注意：以下内容如果访问失败或有其他疑问，可先学习：

SpringSecurity +oauth2+JWT实现统一授权和认证及项目搭建（一）

1 获取当前用户的信息代码为：

Object principal = SecurityContextHolder.getContext().getAuthentication().getPrincipal();

但是，通过运行会发现principal的值只是用户名，没有用户信息，通过去看源码，才发现问题所在，以下是源码：

源码类：DefaultUserAuthenticationConverter.java

通过源码分析，发现这里的map只存储用户名，对此，如果要获取用户，我这里提供的方案是重写该方法，步骤如下：

新建UserAuthenticationConverter.java配置类，继承DefaultUserAuthenticationConverter.java，代码如下：

package com.yty.system.oauth.config.jwt;

import com.yty.system.oauth.entity.SysUser;
import com.yty.system.oauth.entity.vo.SecurityUser;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.AuthorityUtils;
import org.springframework.security.oauth2.provider.token.DefaultUserAuthenticationConverter;
import org.springframework.util.StringUtils;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

@Configuration
public class UserAuthenticationConverter extends DefaultUserAuthenticationConverter {

    private Collection<? extends GrantedAuthority> defaultAuthorities;

    public void setDefaultAuthorities(String[] defaultAuthorities) {
        this.defaultAuthorities = AuthorityUtils.commaSeparatedStringToAuthorityList(StringUtils.arrayToCommaDelimitedString(defaultAuthorities));
    }

    private static final String USER_INFO = "userInfo";

    /**
     * 设置存入认证信息中的Map
     *
     * @param authentication
     * @return
     */
    @Override
    public Map<String, ?> convertUserAuthentication(Authentication authentication) {
        // 入参authentication中保存了完整的用户信息（都已经有完整信息了还查个P）。
        Map<String, Object> map = new HashMap<>(1);
        // 获取用户信息并保存。
        Object o = authentication.getPrincipal();
        SecurityUser userInfo = (SecurityUser) o;
        SysUser sysUser = userInfo.getSysUser();
        map.put(USER_INFO, sysUser);
        // 保存了账户的权限信息，可以通过Authentication..getAuthorities()方法获取。
        if (authentication.getAuthorities() != null && !authentication.getAuthorities().isEmpty()) {
            map.put(AUTHORITIES, AuthorityUtils.authorityListToSet(authentication.getAuthorities()));
        }
        return map;
    }

    /**
     * 选择存入认证信息中的数据
     *
     * @param map
     * @return
     */
    @Override
    public Authentication extractAuthentication(Map<String, ?> map) {
        Authentication authentication = null;
        if (map.containsKey(USER_INFO)) {
            // 将用户对象作为用户信息。
            Object principal = map.get(USER_INFO);
            Collection<? extends GrantedAuthority> authorities = this.getAuthorities(map);
            authentication = new UsernamePasswordAuthenticationToken(principal, "N/A", authorities);
        }
        return authentication;
    }

    private Collection<? extends GrantedAuthority> getAuthorities(Map<String, ?> map) {
        if (!map.containsKey(AUTHORITIES)) {
            return this.defaultAuthorities;
        } else {
            Object authorities = map.get(AUTHORITIES);
            if (authorities instanceof String) {
                return AuthorityUtils.commaSeparatedStringToAuthorityList((String)authorities);
            } else if (authorities instanceof Collection) {
                return AuthorityUtils.commaSeparatedStringToAuthorityList(StringUtils.collectionToCommaDelimitedString((Collection)authorities));
            } else {
                throw new IllegalArgumentException("Authorities must be either a String or a Collection");
            }
        }
    }
}

修改JwtTokenStoreConfig.java类，将以上配置类引用到方法jwtAccessTokenConverter中，具体实现如下：

@Bean
    public JwtAccessTokenConverter jwtAccessTokenConverter() {
        JwtAccessTokenConverter accessTokenConverter = new JwtAccessTokenConverter();

        DefaultAccessTokenConverter defaultAccessTokenConverter = new DefaultAccessTokenConverter();
        defaultAccessTokenConverter.setUserTokenConverter(new UserAuthenticationConverter());
        // 赋予新的Token转换器。
        accessTokenConverter.setAccessTokenConverter(defaultAccessTokenConverter);
        //配置JWT使用的秘钥
        accessTokenConverter.setSigningKey(secret);

        return accessTokenConverter;
    }

在UserDetailService编写静态方法getCurrentUser获取用户信息，代码如下：

/**
     * 获取当前用户信息
     */
    public static SysUser getCurrentUser() {
        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
        if (Objects.isNull(authentication)) {
           throw new RuntimeException("请登录");
        }
        Object principal = authentication.getPrincipal();
        if (Objects.isNull(principal)) {
            throw new RuntimeException("请登录");
        }
        ObjectMapper objectMapper = new ObjectMapper();
        SysUser sysUser = objectMapper.convertValue(principal, SysUser.class);
        return sysUser;
    }

在UserController.java类中编写测试入口方法getCurrentUser，代码如下：

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


    @GetMapping("/getCurrentUser")
    public Object getCurrentUser() {
        SysUser currentUser = UserDetailService.getCurrentUser();
        return currentUser;
    }
}

postman访问：

1 先获取token

2 调用接口http://localhost:8500/oauth_api/user/getCurrentUser，注意参数，需要在请求头中添加参数Authorization，内容为：oken_type+空格+access_token，如图所示：

注意，如果访问不通过，需要在资源配置类中将用户访问接口添加到资源配置ResourceServiceConfig.java中，如无该类，自己新建一个，代码如下所示：

package com.yty.system.oauth.config.jwt;

import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.oauth2.config.annotation.web.configuration.EnableResourceServer;
import org.springframework.security.oauth2.config.annotation.web.configuration.ResourceServerConfigurerAdapter;

@Configuration
@EnableResourceServer
public class ResourceServiceConfig extends ResourceServerConfigurerAdapter {

    @Override
    public void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
                .anyRequest().authenticated()
                // 受保护的资源
                .and().requestMatchers()
                .antMatchers("/user/**");

    }
}