Java中的 KeyStore getKey() 方法及示例

Java.security.KeyStore类的getKey()方法用于获取与给定别名关联的密钥，使用给定的密码来恢复它。

句法：

public final Key getKey(String alias, char[] password)
    throws KeyStoreException, 
           NoSuchAlgorithmException, 
           UnrecoverableKeyException

参数：此方法接受以下参数：

• alias：用来检查密钥的别名
• 密码：这是恢复要检查的密钥的密码

返回值：此方法返回所请求别名的键（如果存在）。

异常：此方法抛出以下异常

• KeyStoreException ：如果未加载密钥库。
• NoSuchAlgorithmException : 如果算法缺失

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 Keystore 'privatekey' 并设置您自己的 Keystore 密码以访问该 Keystore。

以下是说明getKey()方法的示例：

示例 1：

// Java program to demonstrate getKey() 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 Key
            // using getKey() method
            Key key = sr.getKey("ftpkey", pass);
  
            // display the result
            System.out.println("Key : "
                               + key);
        }
  
        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);
        }
        catch (UnrecoverableKeyException e) {
  
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

示例 2：对于KeyStoreException

// Java program to demonstrate getKey() 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 Key
            // using getKey() method
            Key key = sr.getKey("ftpkey", pass);
  
            // display the result
            System.out.println("Key : "
                               + key);
        }
        catch (FileNotFoundException e) {
  
            System.out.println("Exception thrown : " + e);
        }
        catch (NullPointerException e) {
  
            System.out.println("Exception thrown : " + e);
        }
        catch (KeyStoreException e) {
  
            System.out.println("\nException thrown : " + e);
        }
        catch (UnrecoverableKeyException e) {
  
            System.out.println("Exception thrown : " + e);
        }
        catch (NoSuchAlgorithmException e) {
  
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

参考： https://docs.oracle.com/javase/9/docs/api/ Java/security/KeyStore.html#getKey-java.lang.String-char:A-