String testString = "testing signature method";
    Sign.SignatureData signatureData = Sign.signMessage(testString.getBytes(), credentials.getEcKeyPair());

    System.out.println(Numeric.toHexString(credentials.getEcKeyPair().getPublicKey().toByteArray()));
    System.out.println(Numeric.toHexString(testString.getBytes()));
    System.out.println("R: "+Numeric.toHexString(signatureData.getR()));
    System.out.println("S: "+Numeric.toHexString(signatureData.getS()));
    System.out.println("V: "+signatureData.getV());

function verify(bytes32 hash, uint8 v, bytes32 r, bytes32 s) constant returns (address) {

bytes memory prefix = "x19Ethereum Signed Message:n32";
bytes32 prefixedHash = keccak256(prefix, hash);
return ecrecover(prefixedHash, v, r, s);
}

0x60009F80EA2D060fd804285d8a8a649351521582

0x00d309c52c30b15ab6dbd75bf0ffbb2db4124451367fd8fc6fb0bc09f3329607563bcb986bd80d4321feda179219ae59ab7f77052928362d1634c9b72483f78394