java Java 中 KeyStore getKey()方法，示例

Java 中 KeyStore getKey()方法，示例

原文:https://www . geesforgeks . org/keystore-getkey-in-Java-method-with-examples/

java.security.KeyStore 类的 getKey() 方法用于获取与给定别名相关联的密钥，并使用给定的密码对其进行恢复。

语法:

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

参数:该方法接受以下参数:

别名:是用来检查密钥的别名
密码:是恢复要检查的密钥的密码

返回值:该方法返回所请求别名的键(如果存在)。

异常:该方法抛出以下异常

密钥库异常:如果没有加载密钥库。
NoSuchAlgorithmException :如果算法缺失

注意:本文中的所有程序都不会在联机 IDE 上运行，因为不存在“privatekey”密钥库。您可以在系统的 Java 编译器上检查这些代码。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来访问该密钥库。

以下是说明 getKey() 方法的例子:

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);
        }
    }
}

Output:

示例 2: 适用于密钥库异常

// 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);
        }
    }
}