springboot集成jwt代码

很高兴回答您的问题。以下是Spring Boot集成JWT的代码示例：

1. 首先，您需要在pom.xml文件中添加以下依赖项：

<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt-api</artifactId>
    <version>0.11.2</version>
</dependency>
<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt-impl</artifactId>
    <version>0.11.2</version>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt-jackson</artifactId>
    <version>0.11.2</version>
    <scope>runtime</scope>
</dependency>

2. 创建JWT工具类，该类的作用是生成JWT Token，验证JWT Token是否有效，以及获取JWT Token中存储的信息：

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.JwtBuilder;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;

import java.util.Date;

public class JwtUtils {

    private static final String secretKey = "yourSecretKey";
    private static final long expiration = 3600000L;

    public static String generateToken(String subject) {

        long nowMillis = System.currentTimeMillis();
        Date now = new Date(nowMillis);

        JwtBuilder builder = Jwts.builder()
                .setSubject(subject)
                .setIssuedAt(now)
                .setExpiration(new Date(nowMillis + expiration))
                .signWith(SignatureAlgorithm.HS256, secretKey);

        return builder.compact();

    }

    public static boolean validateToken(String token) {

        try {

            Jwts.parser().setSigningKey(secretKey).parseClaimsJws(token);
            return true;

        } catch (Exception ex) {

            return false;

        }

    }

    public static String getUsernameFromToken(String token) {

        Claims claims = Jwts.parser()
                .setSigningKey(secretKey)
                .parseClaimsJws(token)
                .getBody();

        return claims.getSubject();

    }

}

3. 创建JWT拦截器，该拦截器的作用是验证请求的JWT Token是否有效：

import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class JwtInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        String token = request.getHeader("Authorization");

        if (token != null && JwtUtils.validateToken(token)) {

            return true;

        } else {

            response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
            return false;

        }

    }

}

4. 在Spring Boot应用程序中添加JWT拦截器：

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@SpringBootApplication
public class Application implements WebMvcConfigurer {

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

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new JwtInterceptor()).addPathPatterns("/**");
    }

}

现在您可以在应用程序中使用`JwtUtils`类来生成和验证JWT Token。请注意，此示例仅用于演示目的，即使是使用JWT进行身份验证，也需要更多的安全措施。