1.pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.4</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.yl</groupId>
    <artifactId>jwt</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>jwt</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>11</java.version>
    </properties>
    <dependencies>
        <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>
        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.9.1</version>
        </dependency>
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.0</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-impl</artifactId>
            <version>2.3.0</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-core</artifactId>
            <version>2.3.0</version>
        </dependency>
        <dependency>
            <groupId>javax.activation</groupId>
            <artifactId>activation</artifactId>
            <version>1.1.1</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

2.用户实体类

package com.yl.jwt.model;

import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.userdetails.UserDetails;

import java.util.Collection;
import java.util.List;

public class User implements UserDetails {
    private String username;
    private String password;
    private List<GrantedAuthority> authorities;
    @Override
    public Collection<? extends GrantedAuthority> getAuthorities() {
        return null;
    }

    @Override
    public String getPassword() {
        return password;
    }

    @Override
    public String getUsername() {
        return username;
    }

    @Override
    public boolean isAccountNonExpired() {
        return true;
    }

    @Override
    public boolean isAccountNonLocked() {
        return true;
    }

    @Override
    public boolean isCredentialsNonExpired() {
        return true;
    }

    @Override
    public boolean isEnabled() {
        return true;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public void setAuthorities(List<GrantedAuthority> authorities) {
        this.authorities = authorities;
    }
}

3. 自定义认证拦截器，登录成功，则返回token

package com.yl.jwt.filter;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.yl.jwt.model.User;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter;
import org.springframework.security.web.util.matcher.AntPathRequestMatcher;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Collection;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

//登录成功返回token,登录失败返回错误信息
public class JwtLoginFilter extends AbstractAuthenticationProcessingFilter {
    public JwtLoginFilter(String defaultFilterProcessesUrl, AuthenticationManager authenticationManager) {
        super(new AntPathRequestMatcher(defaultFilterProcessesUrl));
        setAuthenticationManager(authenticationManager);
    }

    @Override
    public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException, IOException, ServletException {
        User user = new ObjectMapper().readValue(request.getInputStream(),User.class);
        return getAuthenticationManager().authenticate(new UsernamePasswordAuthenticationToken(user.getUsername(),user.getPassword()));
    }

    //登陆成功
    @Override
    protected void successfulAuthentication(HttpServletRequest request, HttpServletResponse response, FilterChain chain, Authentication authResult) throws IOException, ServletException {
        //获取当前用户的角色
        Collection<? extends GrantedAuthority> authorities = authResult.getAuthorities();
        StringBuilder sb = new StringBuilder();
        for (GrantedAuthority authority : authorities) {
            sb.append(authorities + ",");
        }
        // 构造token
        String token = Jwts.builder()
                .claim("authorities",sb)
                .setSubject(authResult.getName())
                .setExpiration(new Date(System.currentTimeMillis() + 60 * 60 * 1000))
                .signWith(SignatureAlgorithm.HS512,"admin@123")
                .compact();
        Map<String,Object> map = new HashMap<>();
        map.put("token",token);
        map.put("msg","login success");
        response.setContentType("application/json;charset=utf-8");
        PrintWriter writer = response.getWriter();
        writer.write(new ObjectMapper().writeValueAsString(map));
        writer.flush();
        writer.close();
    }

    //登录失败
    @Override
    protected void unsuccessfulAuthentication(HttpServletRequest request, HttpServletResponse response, AuthenticationException failed) throws IOException, ServletException {
        Map<String,Object> map = new HashMap<>();
        map.put("msg","login fail");
        response.setContentType("application/json;charset=utf-8");
        PrintWriter writer = response.getWriter();
        writer.write(new ObjectMapper().writeValueAsString(map));
        writer.flush();
        writer.close();
    }
}

4. 自定义校验拦截器，校验用户每次发请求时携带的token是否正确

package com.yl.jwt.filter;

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jws;
import io.jsonwebtoken.Jwts;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.AuthorityUtils;
import org.springframework.security.core.context.SecurityContext;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.web.filter.GenericFilterBean;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
import java.util.List;

//用于校验每次用户访问接口时携带的token正不正确
public class JwtFilter extends GenericFilterBean {
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest)request;
        //从请求头获取token，注意：前端在传的时候也应当放在请求头里
        String authorization = req.getHeader("authorization");
        Jws<Claims> jws = Jwts.parser()
                .setSigningKey("admin@123")
                .parseClaimsJws(authorization.replaceAll("Bearer", ""));
        Claims body = jws.getBody();
        String username = body.getSubject();
        List<GrantedAuthority> authorities = AuthorityUtils.commaSeparatedStringToAuthorityList((String) body.get("authorities"));
        UsernamePasswordAuthenticationToken token = new UsernamePasswordAuthenticationToken(username,null,authorities);
        SecurityContextHolder.getContext().setAuthentication(token);
        filterChain.doFilter(request,response);


    }
}

5. security的配置

package com.yl.jwt.config;

import com.yl.jwt.filter.JwtFilter;
import com.yl.jwt.filter.JwtLoginFilter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;

@Configuration
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Bean
    PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.inMemoryAuthentication()
                .withUser("root")
                .password("$2a$10$O8G0X/sUPAA76MV7U3BwY.3Uo8/QMBcqK678Rwkoz.fowbce.CLtO") //123
                .roles("root")
                .and()
                .withUser("admin")
                .password("$2a$10$O8G0X/sUPAA76MV7U3BwY.3Uo8/QMBcqK678Rwkoz.fowbce.CLtO") //123
                .roles("admin");
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
                .antMatchers("/root")
                .hasRole("root")
                .antMatchers("/admin")
                .hasRole("admin")
                .antMatchers("/login").permitAll()
                .anyRequest().authenticated()
                .and()
                .addFilterBefore(new JwtLoginFilter("/login",authenticationManager()), UsernamePasswordAuthenticationFilter.class)
                .addFilterBefore(new JwtFilter(),UsernamePasswordAuthenticationFilter.class)
                .csrf().disable();
    }
}

6. controller

package com.yl.jwt.controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {
    @GetMapping("/hello")
    public String hello() {
        return "hello";
    }

    @GetMapping("/admin")
    public String admin() {
        return "hello admin";
    }

    @GetMapping("/root")
    public String root() {
        return "hello root";
    }
}