话不多说，直接上代码。
session_key是与用户微信客户端之间通信的密钥，获取用户信息时会用到。
调用：getSessionKeyAndOpenId方法传入code值，返回openid与session_key，
这里的：
appid: 应用唯一标识，在微信开放平台提交应用审核通过后获得
secret: 应用密钥，也是在微信开放平台获得
把下面代码复制粘贴就能直接用了。
@Service
public class WeChatLoginServiceImpl {@Autowiredprivate WeChatClient weChatClient;private static final String APP_ID = "wx2bxxxxx4c2a8";private static final String APP_SECRET = "72b0ab089db22cc3c9a8e2fxxxxxxx35a";static {Security.addProvider(new BouncyCastleProvider());}//获取微信用户信息public String getUserPortionMsg(WxUserDetails details) {String uxUserMsg = decryptData(details.getEncryptedData(), details.getSession_key(), details.getIv(), "UTF-8");return uxUserMsg;}// 用于加密与解密public static String decryptData(String data, String key, String iv, String encodingFormat) {try {byte[] dataByte = Base64.decodeBase64(data);byte[] keyByte = Base64.decodeBase64(key);byte[] ivByte = Base64.decodeBase64(iv);Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding"); // 修改这里SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");parameters.init(new IvParameterSpec(ivByte));cipher.init(Cipher.DECRYPT_MODE, spec, parameters);byte[] resultByte = cipher.doFinal(dataByte);if (resultByte != null && resultByte.length > 0) {return new String(resultByte, encodingFormat);}return null;} catch (Exception e) {e.printStackTrace();throw new RuntimeException("解密失败：" + e.getMessage(), e);}}// 返回sessionKey和OpenIdpublic LoginCertificate getSessionKeyAndOpenId(String code) {String jsonResponse = weChatClient.getOpenId(APP_ID, APP_SECRET, code, "authorization_code");LoginCertificate loginCertificate;try {// 将JSON字符串解析为LoginCertificate对象loginCertificate = JSON.parseObject(jsonResponse, LoginCertificate.class);} catch (Exception e) {return null;}return loginCertificate;}
}@Data
public class WxUserDetails {// 错误消息：如果请求成功，通常为 "getPhoneNumber:ok"private String errMsg;// 加密数据：包含敏感信息如用户的手机号码，需要使用session_key进行解密private String encryptedData;// 加密算法的初始向量：用于解密encryptedDataprivate String iv;// 用户的登录凭证（code）：在用户登录时获取，用于请求session_key和openidprivate String code;// 用于解密的session_keyprivate String session_key;// 用户的openidprivate String openid;
}@Data
public class LoginCertificate {private String openid;private String session_key;
}
@FeignClient(name = "weChatClient", url = "https://api.weixin.qq.com")
public interface WeChatClient {/*** 获取微信的openid和session_key* @param appId* @param secret* @param code* @param grantType* @return*/@GetMapping("/sns/jscode2session")String getOpenId(@RequestParam("appid") String appId,@RequestParam("secret") String secret,@RequestParam("js_code") String code,@RequestParam("grant_type") String grantType);
}
)
