jwt 生成token 双向不对称加密

用到了这个包 compile 'io.jsonwebtoken:jjwt:0.9.1'
可以到这里去生成一堆密钥 http://web.chacuo.net/netrsakeypair

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

import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.time.LocalDateTime;
import java.util.Base64;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

import static java.time.ZoneOffset.UTC;

public class TokenHelper {


    static String publicKey = "QgkAQIDAQAB";
    static String privateKey = "MIICdQIBADANBgkqhkiG9w0BAQEFAASCAl8";

    public static Claims parseJwt(String jsonWebToken) {
        if (jsonWebToken == null || !jsonWebToken.startsWith("Bearer ")) {
            throw new RuntimeException("token is not valid");
        }
        try{
            return Jwts.parser().setSigningKey(getPublicKey())
                    .parseClaimsJws(jsonWebToken.substring(7)).getBody();
        }catch (Exception e){
            e.printStackTrace();
        }
        return null;
    }

    public static String createToken () {
        Date expiration = Date.from(LocalDateTime.now(UTC).plusDays(7).toInstant(UTC));

        Map<String, Object> claims = new HashMap<>();
        claims.put("companyId", "1");
        claims.put("userId", "2");
        // 这里要注意 用到了setClaims 方法 setSubject  和 setExpiration 就不好用了
        // 可以把这两个值也放到claims里 或者不用setClaims 用 setClaim 一个一个放
        return "Bearer " + Jwts.builder()
                .setSubject("subject")
                .setExpiration(expiration)
                .setClaims(claims)
                .setIssuer("test1")
                .signWith(SignatureAlgorithm.RS256, getPrivateKey())
                .compact();
    }

    public static PublicKey getPublicKey(){
        try{
            byte[] keyBytes = Base64.getDecoder().decode(publicKey.getBytes());
            X509EncodedKeySpec keySpec=new X509EncodedKeySpec(keyBytes);
            KeyFactory keyFactory=KeyFactory.getInstance("RSA");
            return keyFactory.generatePublic(keySpec);
        }catch (Exception e){
            e.printStackTrace();
        }
        return null;
    }

    public static PrivateKey getPrivateKey() {

        try {
            byte[] keyBytes;
            keyBytes = Base64.getDecoder().decode(privateKey.getBytes());
            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            return keyFactory.generatePrivate(keySpec);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }
}