Java中的 KeyStore getCreationDate() 方法及示例

Java.security.KeyStore类的getCreationDate()方法用于借助指定别名获取指定条目的创建日期。

句法：

public final Date getCreationDate(String alias)
    throws KeyStoreException

参数：此方法接受别名的名称作为要获取其创建日期的参数。

返回值：此方法返回所请求别名的创建日期（如果存在）。

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getCertificateChain()方法的示例：

示例 1：

// Java program to demonstrate getCreationDate() 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 date of Creation
            // using getCreationDate() method
            Date date
                = sr.getCreationDate("ftpkey");
  
            // display the result
            System.out.println("Creation date : "
                               + date.toString());
        }
  
        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 program to demonstrate getCreationDate() 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 date of Creation
            // using getCreationDate() method
            Date date
                = sr.getCreationDate("ftpkey");
  
            // display the result
            System.out.println("Creation date : "
                               + date.toString());
        }
        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#getCreationDate-java.lang.String-