如何修复此异常：线程“main”中的异常 java.lang.ClassCastException

Question

异常是：线程“main”中的异常 java.lang.ClassCastException: [Ljava.security.cert.Certificate;无法转换为 [Ljava.security.cert.X509Certificate;

在keystore.jks文件中，它有一个入口，它的别名是“/btsmed-1/certh-1/necert-1”，这个keystore.jks文件中的证书链是通过这个方法设置的：

keystore.setKeyEntry(alias, Keys.keyPair().getPrivate(),KEY_STORE_PASSWORD.toCharArray(), certChain);
keystore.store(out, KEY_STORE_PASSWORD.toCharArray());

在我将 jks 重新加载到密钥库之前，执行此语句时：

X509Certificate[] certs1 = (X509Certificate[])keystore.getCertificateChain(alias);

它不会抛出强制转换异常。

但是在 keystore.load(fIn, password); 之后执行此语句时会抛出强制转换异常：

X509Certificate[] certs1 = (X509Certificate[]) keystore.getCertificateChain(alias);

====================下面是源代码。

public class KeystoreLoad {

    public static void main(String[] args) throws Exception {
      char[] password = "nokia123".toCharArray();
      String alias = "/btsmed-1/certh-1/necert-1";

      KeyStore keystore = KeyStore.getInstance("JKS");

      keystore.load(null, null);

      FileInputStream fIn = new FileInputStream("d://keystore/keystore.jks");

      keystore.load(fIn, password);

      X509Certificate[] certs1 = (X509Certificate[]) keystore.getCertificateChain(alias);
      System.out.println(Arrays.toString(certs1));

    }

}

Answer 1

这是因为java编译器不知道getCertificateChain()方法返回的Certificate[]中的所有对象是否只包含X509Certificate[尽管X509Certificate是唯一扩展@987654325的类@类截至目前]。

因此，如果您需要 X509Certificate[]，则必须遍历 Certificate[]，如下所示：

Certificate[] certChain = ks.getCertificateChain("ALIAS");

X509Certificate[] x509CertChain = new X509Certificate[certChain.length];
for (int i = 0; i < certChain.length; i++)
    x509CertChain[i] = (X509Certificate) certChain[i];

Answer 2

试试这个

import java.io.FileInputStream;
import java.security.KeyStore;
import java.util.Arrays;

import java.security.cert.X509Certificate;

public class TestDemo {

    public static void main(String[] args) throws Exception {

        char[] password = "nokia123".toCharArray();
        String alias = "/btsmed-1/certh-1/necert-1";

        KeyStore keystore = KeyStore.getInstance("JKS");

        keystore.load(null, null);

        FileInputStream fIn = new FileInputStream("d://keystore/keystore.jks");

        keystore.load(fIn, password);
        keystore.getCertificateChain(alias);
        X509Certificate[] certs1 = (X509Certificate[]) keystore.getCertificateChain(alias);

        System.out.println(Arrays.toString(certs1));

    }

}

知道如何使用 javax.security.cert.X509Certificate java.security.cert.X509Certificate