java pfx_如何在Java中读取.pfx文件的内容？

我有file.pfx文件,还有一个私钥.如何在

Java中读取file.pfx中的证书？

我用过这段代码：

import java.security.*;

import java.security.cert.Certificate;

import java.security.cert.X509Certificate;

import java.security.cert.CertificateException;

import javax.crypto.SecretKey;

import javax.security.auth.callback.*;

//These packages I have used.

public String readFile(String fn) {

String thisLine, ret = “”;

KeyStore ks = KeyStore.getInstance(“pkcs12”, “SunJSSE”);

ks.load(new FileInputStream(fn),”password”.toCharArray());

try {

Key key = ks.getKey(“1”, “password”.toCharArray());

Certificate[] cc = ks.getCertificateChain(“1”);

X509Certificate certificate1 = (X509Certificate) cc[0];//Here it throws java.lang.NullPointerException

ret += certificate1.getNotAfter();

ret += certificate1.getNotBefore();

} catch(Exception e) {

ret = “Cannot load, exception!”;

}

return ret;

}