用springboot框架写一个jwt登录操作

好的，我可以为您提供有关使用springboot框架编写JWT登录操作的信息。首先，您需要在springboot项目中设置JWT身份验证过滤器，并使用密钥对JWT进行签名和验证。

在您的springboot项目中，您可以使用spring-security-jwt来实现JWT身份验证。您可以添加以下依赖项到您的项目中：

<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt</artifactId>
    <version>0.9.1</version>
</dependency>

您还需要在您的项目中创建JWT工具类，并设置JWT的过期时间、密钥等信息。以下是一个示例代码：

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import io.jsonwebtoken.security.Keys;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.stereotype.Component;

import java.security.Key;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.function.Function;

@Component
public class JwtUtil {
    private Key key = Keys.secretKeyFor(SignatureAlgorithm.HS256);

    private String extractUsername(String token) {
        return extractClaim(token, Claims::getSubject);
    }

    private Date extractExpiration(String token) {
        return extractClaim(token, Claims::getExpiration);
    }

    private <T> T extractClaim(String token, Function<Claims, T> claimsResolver) {
        final Claims claims = extractAllClaims(token);
        return claimsResolver.apply(claims);
    }

    private Claims extractAllClaims(String token) {
        return Jwts.parserBuilder().setSigningKey(key).build().parseClaimsJws(token).getBody();
    }

    private Boolean isTokenExpired(String token) {
        return extractExpiration(token).before(new Date());
    }

    public String generateToken(UserDetails userDetails) {
        Map<String, Object> claims = new HashMap<>();
        return createToken(claims, userDetails.getUsername());
    }

    private String createToken(Map<String, Object> claims, String subject) {
        return Jwts.builder().setClaims(claims).setSubject(subject).setIssuedAt(new Date(System.currentTimeMillis()))
                .setExpiration(new Date(System.currentTimeMillis() + 1000 * 60 * 60 * 10))
                .signWith(key).compact();
    }

    public Boolean validateToken(String token, UserDetails userDetails) {
        final String username = extractUsername(token);
        return (username.equals(userDetails.getUsername()) && !isTokenExpired(token));
    }
}

您还需要在您的项目中创建一个JWT身份验证过滤器。过滤器将检查请求的身份验证凭据，如果凭据有效，则将其授权给用户。以下是一个示例代码：

import io.jsonwebtoken.ExpiredJwtException;
import org.springframework.beans.factory.annotation.Autowired;
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.userdetails.UserDetailsService;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class JwtAuthenticationFilter extends UsernamePasswordAuthenticationFilter {

    @Autowired
    private AuthenticationManager authenticationManager;

    @Autowired
    private JwtUtil jwtUtil;

    @Autowired
    private UserDetailsService userDetailsService;

    @Override
    public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException {

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

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

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

        username = username.trim();

        UsernamePasswordAuthenticationToken authenticationToken = new UsernamePasswordAuthenticationToken(username, password);

        return authenticationManager.authenticate(authenticationToken);
    }

    @Override
    protected void successfulAuthentication(HttpServletRequest request, HttpServletResponse response, FilterChain chain, Authentication authResult) throws IOException, ServletException {

        String username = ((org.springframework.security.core.userdetails.User) authResult.getPrincipal()).getUsername();
        String token = jwtUtil.generateToken(userDetailsService.loadUserByUsername(username));
        response.addHeader("Authorization", "Bearer " + token);
    }

    @Override
    protected void unsuccessfulAuthentication(HttpServletRequest request, HttpServletResponse response, AuthenticationException failed) throws IOException, ServletException {
        super.unsuccessfulAuthentication(request, response, failed);
    }
}

以上就是使用springboot框架编写JWT登录操作的基本步骤。希望对您有所帮助！