1，下载Cursor软件
2，左侧文件栏目新建一个first.java
3，在编辑区输入“//使用RSA公私钥实现JWT令牌的签名和验签”，并且连续输入两个回车（相当于调用Ctrl+K）
AI会自动生成代码，点击“Accept all” ,可以看到AI生成了一个JwtUtil的类，代码如下：
//使用RSA公私钥实现JWT令牌的签名和验签import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.util.Base64;public class JwtUtil {private static final String ALGORITHM = "RSA";private static final String SIGNATURE_ALGORITHM = "SHA256withRSA";public static String sign(String payload, String privateKeyStr) throws Exception {byte[] payloadBytes = payload.getBytes();byte[] privateKeyBytes = Base64.getDecoder().decode(privateKeyStr);PrivateKey privateKey = KeyUtil.getPrivateKey(privateKeyBytes, ALGORITHM);Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);signature.initSign(privateKey);signature.update(payloadBytes);byte[] signedBytes = signature.sign();return Base64.getEncoder().encodeToString(signedBytes);}public static boolean verify(String payload, String signatureStr, String publicKeyStr) throws Exception {byte[] payloadBytes = payload.getBytes();byte[] signatureBytes = Base64.getDecoder().decode(signatureStr);byte[] publicKeyBytes = Base64.getDecoder().decode(publicKeyStr);PublicKey publicKey = KeyUtil.getPublicKey(publicKeyBytes, ALGORITHM);Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);signature.initVerify(publicKey);signature.update(payloadBytes);return signature.verify(signatureBytes);}private static class KeyUtil {static PrivateKey getPrivateKey(byte[] privateKeyBytes, String algorithm) throws Exception {KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(algorithm);keyPairGenerator.initialize(2048);KeyPair keyPair = keyPairGenerator.generateKeyPair();return keyPair.getPrivate();}static PublicKey getPublicKey(byte[] publicKeyBytes, String algorithm) throws Exception {KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(algorithm);keyPairGenerator.initialize(2048);KeyPair keyPair = keyPairGenerator.generateKeyPair();return keyPair.getPublic();}}
}AI生成了一个sign函数根据参数字符串（JSON格式）和私有秘钥生成签名，verify根据共用秘钥和参数解密并验证签名有效性，KeyUtil内部类可以分别获取私有秘钥和公共秘钥
4，代码窗口输入//test 按Ctrl+K进入AI对话页面，连续回车两次，自动生成代码：
接收之后可以看到，生成了一个产生令牌和验证令牌有效性的代码：
public static String generateToken(String payload, String privateKeyStr) throws Exception {String signature = sign(payload, privateKeyStr);return Base64.getEncoder().encodeToString(payload.getBytes()) + "." + signature;}public static boolean verifyToken(String token, String publicKeyStr) throws Exception {String[] parts = token.split("\\.");if (parts.length != 2) {return false;}String payload = new String(Base64.getDecoder().decode(parts[0]));String signature = parts[1];return verify(payload, signature, publicKeyStr);}可以直接用参数JSON字符串和私有秘钥直接生成token，传入token和公共秘钥可以验证token
5，代码窗口输入“//main函数测试”，按住"Ctrl+K"，连续回车两次：
生成代码：
//main函数测试public static void main(String[] args) throws Exception {String payload = "hello world";KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(ALGORITHM);keyPairGenerator.initialize(2048);KeyPair keyPair = keyPairGenerator.generateKeyPair();PrivateKey privateKey = keyPair.getPrivate();PublicKey publicKey = keyPair.getPublic();String privateKeyStr = Base64.getEncoder().encodeToString(privateKey.getEncoded());String publicKeyStr = Base64.getEncoder().encodeToString(publicKey.getEncoded());String token = generateToken(payload, privateKeyStr);System.out.println("token: " + token);boolean verifyResult = verifyToken(token, publicKeyStr);System.out.println("verifyResult: " + verifyResult);}可以看到AI，帮我们生成了完整的RSA token加密解密的全流程代码。经过测试，我已经应用到了实际项目中了。
后续本人还在Cursor界面中调试运行了该段Java代码，下次再介绍。
