Java中的 KeyStore getCertificateAlias() 方法及示例

Java.security.KeyStore类的getCertificateAlias()方法用于获取具有指定证书的第一个 KeyStore 条目的名称。
句法：

public final String getCertificateAlias(Certificate cert)
    throws KeyStoreException

参数：此方法接受证书名称一个参数，该参数将与 Keystore 条目匹配。
返回值：此方法返回具有指定证书的第一个 KeyStore 条目的名称。
异常：如果您不初始化此密钥库，此方法将引发KeyStoreException 。
注意：本文中的所有程序都不会在在线 IDE 上运行，因为不存在“privatekey”密钥库。您可以在系统上的Java编译器上检查此代码。要检查此代码，请在您的系统上创建一个密钥库“privatekey”并设置您自己的密钥库密码以访问该密钥库。
以下是说明getCertificate()方法的示例：
示例 1：

Java

// Java program to demonstrate getCertificate() method
 
import java.security.*;
import java.security.cert.*;
import java.util.*;
import java.io.*;
 
public class GFG {
    public static void main(String[] argv)
    {
        try {
 
            // creating the object of KeyStore
            // and getting instance
            // By using getInstance() method
            KeyStore sr = KeyStore.getInstance("JKS");
 
            // keystore password is required to access keystore
            char[] pass = ("123456").toCharArray();
 
            // creating and initializing object of InputStream
            InputStream is
                = new FileInputStream(
                    "f:/java/private Key.store");
 
            // initializing keystore object
            sr.load(is, pass);
 
            // getting the certificate
            X509Certificate cert
                = (X509Certificate)sr
                      .getCertificate("ftpkey");
 
            // getting alias name for the keyentry
            // using getCertificateAlias() method
            String alias = sr.getCertificateAlias(cert);
 
            // display the result
            System.out.println("alias name for the particular entry : "
                               + alias);
        }
 
        catch (NoSuchAlgorithmException e) {
 
            System.out.println("Exception thrown : " + e);
        }
        catch (NullPointerException e) {
 
            System.out.println("Exception thrown : " + e);
        }
        catch (KeyStoreException e) {
 
            System.out.println("Exception thrown : " + e);
        }
        catch (FileNotFoundException e) {
 
            System.out.println("Exception thrown : " + e);
        }
        catch (IOException e) {
 
            System.out.println("Exception thrown : " + e);
        }
        catch (CertificateException e) {
 
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

示例 2：对于KeyStoreException

Java

// Java program to demonstrate getCertificateAlias() method
 
import java.security.*;
import java.security.cert.*;
import java.util.*;
import java.io.*;
 
public class GFG {
    public static void main(String[] argv)
    {
        try {
 
            // creating the object of KeyStore
            // and getting instance
            // By using getInstance() method
            KeyStore sr = KeyStore.getInstance("JKS");
 
            // keystore password is required to access keystore
            char[] pass = ("123456").toCharArray();
 
            // creating and initializing object of InputStream
            InputStream is
                = new FileInputStream(
                    "f:/java/private Key.store");
 
            // initializing keystore object
            // sr.load(is, pass);
 
            // getting the certificate
            X509Certificate cert
                = (X509Certificate)sr
                      .getCertificate("ftpkey");
 
            // getting alias name for the keyentry
            // using getCertificateAlias() method
            String alias = sr.getCertificateAlias(cert);
 
            // display the result
            System.out.println("alias name for the particular entry : "
                               + alias);
        }
        catch (FileNotFoundException e) {
 
            System.out.println("Exception thrown : " + e);
        }
        catch (NullPointerException e) {
 
            System.out.println("Exception thrown : " + e);
        }
        catch (KeyStoreException e) {
 
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

参考： https://docs.oracle.com/javase/9/docs/api/ Java/security/KeyStore.html#getCertificateAlias-java.security.cert.Certificate-