java使用证书链验证证书

在Java中，可以使用javax.net.ssl包中的SSLContext和TrustManager来验证证书链。下面是一个简单的示例：

import java.io.FileInputStream;
import java.security.KeyStore;
import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.TrustManagerFactory;
import javax.net.ssl.X509TrustManager;

public class CertificateVerifier {
    public static void main(String[] args) throws Exception {
        String keystorePath = "path/to/keystore";
        String keystorePassword = "keystorePassword";
        String truststorePath = "path/to/truststore";
        String truststorePassword = "truststorePassword";

        // Load keystore
        KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
        keystore.load(new FileInputStream(keystorePath), keystorePassword.toCharArray());

        // Load truststore
        KeyStore truststore = KeyStore.getInstance(KeyStore.getDefaultType());
        truststore.load(new FileInputStream(truststorePath), truststorePassword.toCharArray());

        // Create SSL context
        TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
        tmf.init(truststore);
        SSLContext sslContext = SSLContext.getInstance("TLS");
        sslContext.init(null, tmf.getTrustManagers(), null);

        // Create trust manager
        X509TrustManager trustManager = (X509TrustManager) tmf.getTrustManagers()[0];

        // Verify certificate chain
        X509Certificate[] chain = (X509Certificate[]) keystore.getCertificateChain("alias");
        trustManager.checkServerTrusted(chain, "RSA");
    }
}

在上面的示例中，我们首先加载了keystore和truststore，然后使用TrustManagerFactory将truststore初始化为信任管理器，并将其传递给SSLContext。然后，我们从trustManager获取X509TrustManager对象，并使用它来验证证书链。

请注意，此代码示例仅用于演示目的。在实际使用中，您需要使用自己的keystore和truststore，并使用正确的alias和密码。

希望这可以帮助您理解如何在Java中验证证书链。