是这种格式的{ "alg": "RS256", "e": "AQAB", "ext": true, "key_ops": [ "verify" ], "kty": "RSA", "n": "txeBjjyVHAi2X03MmK51kBgHjXrK5G-wI4NvmMA8XgYjZnf3pPuWmUOuU4Q1ZOnyWrMaY2Evuflup1aa809wqlhI5KpAWOk3IjeZL8JNMQQvB60gtqtBZD0FULPoy31BdVwXBRM6X0jvqSZwJJnn3cUxrA_qmawbAYXiXJhGjZPgH3dk9_a2Y0TFjc9y2H79EGcK7dPmeeLBgtowMjF9-vLXpF1xuuvxMdG4KO_EMzsXdTADEFf6KwXW0LRcDKdJaiI-qEwP1LoETyZL-BU_TOiTZbe8BMmlH7dCTxc0_1GZwiSSvR0OfRel5pxjh8aZBpC7DPcNDsFxergyiSswmw" }

对于这种格式的JSON字符串，您可以使用以下代码来生成`RSAPublicKey`对象：

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

import java.io.StringReader;
import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.PublicKey;
import java.security.spec.RSAPublicKeySpec;
import java.util.Base64;

public class Main {
    public static void main(String[] args) throws Exception {
        // 假设您有一个JSON字符串，其中包含公钥信息
        String jsonString = "{\"alg\":\"RS256\",\"e\":\"AQAB\",\"ext\":true,\"key_ops\":[\"verify\"],\"kty\":\"RSA\",\"n\":\"txeBjjyVHAi2X03MmK51kBgHjXrK5G-wI4NvmMA8XgYjZnf3pPuWmUOuU4Q1ZOnyWrMaY2Evuflup1aa809wqlhI5KpAWOk3IjeZL8JNMQQvB60gtqtBZD0FULPoy31BdVwXBRM6X0jvqSZwJJnn3cUxrA_qmawbAYXiXJhGjZPgH3dk9_a2Y0TFjc9y2H79EGcK7dPmeeLBgtowMjF9-vLXpF1xuuvxMdG4KO_EMzsXdTADEFf6KwXW0LRcDKdJaiI-qEwP1LoETyZL-BU_TOiTZbe8BMmlH7dCTxc0_1GZwiSSvR0OfRel5pxjh8aZBpC7DPcNDsFxergyiSswmw\"}";

        // 使用JsonParser解析JSON字符串
        JsonParser parser = new JsonParser();
        JsonObject jsonObject = parser.parse(new StringReader(jsonString)).getAsJsonObject();

        // 获取公钥的n和e值，并进行Base64解码
        String nValue = jsonObject.get("n").getAsString();
        String eValue = jsonObject.get("e").getAsString();
        byte[] nBytes = Base64.getUrlDecoder().decode(nValue);
        byte[] eBytes = Base64.getUrlDecoder().decode(eValue);

        // 使用n和e值生成RSAPublicKeySpec对象
        RSAPublicKeySpec keySpec = new RSAPublicKeySpec(new BigInteger(1, nBytes), new BigInteger(1, eBytes));

        // 使用KeyFactory和RSAPublicKeySpec生成RSAPublicKey对象
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        PublicKey publicKey = keyFactory.generatePublic(keySpec);

        // 打印生成的RSAPublicKey对象
        System.out.println(publicKey);
    }
}

这段代码将从JSON字符串中提取出`n`和`e`的值，并进行Base64解码。然后，使用这些值创建`RSAPublicKeySpec`对象，并使用`KeyFactory`和`RSAPublicKeySpec`生成`RSAPublicKey`对象。打印输出的结果将是生成的`RSAPublicKey`对象。