从"Blog"仓库中分离出来

src/main/java/cn/celess/blog/util/JwtUtil.java

@@ -0,0 +1,93 @@
+package cn.celess.blog.util;
+
+import cn.celess.blog.entity.User;
+import io.jsonwebtoken.Claims;
+import io.jsonwebtoken.ExpiredJwtException;
+import io.jsonwebtoken.Jwts;
+import io.jsonwebtoken.SignatureAlgorithm;
+import org.springframework.stereotype.Component;
+
+import java.time.Instant;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * @Author: 小海
+ * @Date: 2019/11/16 11:26
+ * @Description: JWT工具类
+ */
+@Component
+public class JwtUtil {
+    private static final String CLAIM_KEY_USERNAME = "sub";
+
+    /**
+     * 5天(毫秒)
+     */
+    public static final long EXPIRATION_LONG_TIME = 432000000;
+
+    /**
+     * 两小时（毫秒）
+     */
+    public static final long EXPIRATION_SHORT_TIME = 7200000;
+    /**
+     * JWT 秘钥需自行设置不可泄露
+     */
+    private static final String SECRET = "xxx";
+
+
+    public String generateToken(User user, boolean isRemember) {
+        Map<String, Object> claims = new HashMap<>(16);
+        claims.put(CLAIM_KEY_USERNAME, user.getEmail());
+
+        return Jwts.builder()
+                .setClaims(claims)
+                .setExpiration(new Date(Instant.now().toEpochMilli() + (isRemember ? EXPIRATION_LONG_TIME : EXPIRATION_SHORT_TIME)))
+                .signWith(SignatureAlgorithm.HS512, SECRET)
+                .compact();
+    }
+
+    public Boolean validateToken(String token, User user) {
+        String username = getUsernameFromToken(token);
+
+        return (username.equals(user.getEmail()) && !isTokenExpired(token));
+    }
+
+    /**
+     * 获取token是否过期
+     */
+    public Boolean isTokenExpired(String token) {
+        try {
+            Date expiration = getExpirationDateFromToken(token);
+            return expiration.before(new Date());
+        } catch (ExpiredJwtException e) {
+            return true;
+        }
+    }
+
+    /**
+     * 根据token获取username
+     */
+    public String getUsernameFromToken(String token) {
+        return getClaimsFromToken(token).getSubject();
+    }
+
+    /**
+     * 获取token的过期时间
+     */
+    public Date getExpirationDateFromToken(String token) {
+        return getClaimsFromToken(token).getExpiration();
+    }
+
+    /**
+     * 解析JWT
+     */
+    private Claims getClaimsFromToken(String token) {
+        Claims claims = Jwts.parser()
+                .setSigningKey(SECRET)
+                .parseClaimsJws(token)
+                .getBody();
+        return claims;
+    }
+
+}