java 用代码 操作 keystore

以下是Java代码操作keystore的示例：

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.security.KeyStore;
import java.security.cert.Certificate;

public class KeystoreExample {

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

        // Load the keystore file
        String keystorePath = "path/to/keystore";
        char[] keystorePassword = "keystorePassword".toCharArray();
        KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
        FileInputStream inputStream = new FileInputStream(keystorePath);
        keyStore.load(inputStream, keystorePassword);
        inputStream.close();

        // Get the certificate
        String alias = "certificateAlias";
        Certificate certificate = keyStore.getCertificate(alias);

        // Save the certificate to a file
        String outputPath = "path/to/certificateFile";
        FileOutputStream outputStream = new FileOutputStream(outputPath);
        outputStream.write(certificate.getEncoded());
        outputStream.close();
    }
}

这个示例代码可以加载一个 keystore 文件，获取一个指定别名的证书，并将证书保存到一个文件中。关键是要熟悉 KeyStore 类的使用方法，包括加载、存储、获取证书等。