Does it have a way to get PublicKey as a String

Question

I want to implement RSA in java and javascript. But it seems there is no way to receive a public key as a String in Java API (cause i need to use the key in javascript at client side)
I want to know whether this implementation is possible or not.
Thx

Answer 1

The following code snippet should read a X509Certificate out of a file and extract the modulus and the public exponent as instances of the class BigInteger.
String filename;
FileInputStream fis;
BufferedInputStream bis;
CertificateFactory cf;
X509Certificate cert;
try
    fis = new FileInputStream(filename);
    bis = new BufferedInputStream(fis);
    cf = CertificateFactory.getInstance("X.509");
    while (bis.available() > 0)
        cert = (java.security.cert.X509Certificate)
               cf.generateCertificate(bis);
    RSAPublicKey rsaPublicKey = (RSAPublicKey)cert.getPublicKey();
    BigInteger   modulus = rsaPublicKey.getModulus();
    BigInteger   exponent = rsaPublicKey.getPublicExponent();
catch( Exception e )
}