从字节[]生成X509Certificate？

是否有可能从 byte[] 生成 java.security.cert.X509Certificate ？

Sure.

证书对象可以通过实例创建证书工厂 http://docs.oracle.com/javase/7/docs/api/java/security/cert/CertificateFactory.html- 特别是，配置为创建 X509 证书。可以这样创建：

CertificateFactory certFactory = CertificateFactory.getInstance("X.509");

然后您需要向其传递一个包含证书字节的InputStream。这可以通过将字节数组包装在字节数组输入流 http://docs.oracle.com/javase/7/docs/api/java/io/ByteArrayInputStream.html:

InputStream in = new ByteArrayInputStream(bytes);
X509Certificate cert = (X509Certificate)certFactory.generateCertificate(in);