错误[Ljava.lang.Object;将 X509Certificate 的数组列表转换为数组时，无法转换为 [Ljava.security.cert.X509Certificate

我对这个 ssl 和证书很陌生。我有一个 jks 文件，其中包含服务器信任的一些证书。我试图从 jks 文件中读取所有证书并将其返回到 getAcceptedIssuers() 方法。证书的类型为 X509Certificate。 我实现的方法正确读取 jks 文件并创建 X509Certificate 证书的数组列表。接下来，当我尝试将 arraylist 转换为数组时，出现此异常

[Ljava.lang.Object; cannot be cast to [Ljava.security.cert.X509Certificate;
    at com.sample.ssl.GetCertificates.loadCertificatesFromCompanJks(GetCertificates.java:125)
    at com.sample.ssl.GetCertificates$1.getAcceptedIssuers(GetCertificates.java:44)
    at sun.security.ssl.AbstractTrustManagerWrapper.checkAlgorithmConstraints(Unknown Source)
    at sun.security.ssl.AbstractTrustManagerWrapper.checkAdditionalTrust(Unknown Source)
    at sun.security.ssl.AbstractTrustManagerWrapper.checkServerTrusted(Unknown Source)
    at sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
    at sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
    at sun.security.ssl.Handshaker.processLoop(Unknown Source)
    at sun.security.ssl.Handshaker.process_record(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.getSession(Unknown Source)
    at org.apache.http.conn.ssl.AbstractVerifier.verify(AbstractVerifier.java:91)
    at org.apache.http.conn.ssl.SSLSocketFactory.connectSocket(SSLSocketFactory.java:397)
    at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:148)
    at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:149)
    at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:121)
    at org.apache.http.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:573)
    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:425)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:820)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:754)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:732)
    at com.sample.ssl.GetCertificates.postMessage(GetCertificates.java:82)
    at com.sample.ssl.GetCertificates.main(GetCertificates.java:138)

我的代码如下

public class GetCertificates {
    static private TrustManager[] trustmgr = new TrustManager[]{new X509TrustManager() {

        private X509Certificate[] certs = null;

        public void checkClientTrusted(X509Certificate[] certs, String authType) {
            System.out.println("checkClientTrusted");
        }

        public void checkServerTrusted(X509Certificate[] certs, String authType) {
            System.out.println("checkServerTrusted");
        }

        public X509Certificate[] getAcceptedIssuers() {
            System.out.println("getAcceptedIssuers");
            certs = loadCertificatesFromCompanJks("C:/Users/vinod/Desktop/keystore.jks", "mypassword");
            // return new
            // X509Certificate[]{};
            return certs;
        }
    }};

    public void postMessage() {
        try {
            // here I prepare Url to execute and make a call
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    public static X509Certificate[] loadCertificatesFromCompanJks(String jksPath, String keyStorePassword) {
        try {
            X509Certificate X509Certificate[] = null;
            Certificate[] certs = null;

            ArrayList<X509Certificate> serverCerts = new ArrayList<X509Certificate>();
            FileInputStream is = new FileInputStream(jksPath);
            KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
            String password = keyStorePassword;
            keystore.load(is, password.toCharArray());

            Enumeration e = keystore.aliases();
            for (; e.hasMoreElements(); ) {

                String alias = (String) e.nextElement();
                Certificate cert = keystore.getCertificate(alias);
                X509Certificate cert1 = (X509Certificate) cert;
                serverCerts.add(cert1);
            }
            is.close();
            System.out.println("Number of server certificates : " + serverCerts.size());
            X509Certificate = (java.security.cert.X509Certificate[]) serverCerts.toArray();
            return X509Certificate;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public static void main(String[] args) {
        new GetCertificates().postMessage();
    }
}

你的错误在这里：

X509Certificate = (java.security.cert.X509Certificate[]) serverCerts.toArray();

那个超载的toArray()将返回一个Object[] and an Object[]无法转换为不同的数组类型。

将该行更改为：

X509Certificate = serverCerts.toArray(new X509Certificate[serverCerts.size()]);

在这里，您分配正确类型和大小的数组，并将其传递给toArray从列表中填写。

（你也可以这样写...

X509Certificate = serverCerts.toArray(new X509Certificate[0]);

...但这会导致不必要的分配。请阅读 javadoctoArray(...)为了更好的理解。 （不可否认，额外分配的成本很小，您可以通过传递预分配/共享的零大小数组来避免它。））

在此过程中，更改变量名称以符合 Java 样式约定。在同一行代码中对类型和变量使用相同的标识符是非常令人困惑的！