KeyStore getEntry() method in Java with Examples - GeeksforGeeks

28 Nov, 2021
The getEntry() method of java.security.KeyStore class is used to get the keystore entry for this instance with the help of the specified alias and the protection parameter.
Syntax:
public final KeyStore.Entry
  getEntry(String alias, 
           KeyStore.ProtectionParameter protParam)
    throws NoSuchAlgorithmException, 
           UnrecoverableEntryException, 
           KeyStoreException
Parameter: This method accepts following arguments as a parameter.
alias: which is name of the Keystore Entry to be fetched.
protParam: which contains the password to access keystore.
Return Value: This method returns the keystore entry for the requested alias if it exists.
Exception: This method throws following exception
NullPointerException: for null alias.
NoSuchAlgorithmException: if the algorithm is missing.
UnrecoverableEntryException: if the specified password is invalid.
KeyStoreException: if the keystore has not been initialized (loaded).
Note: All the programs in this article won’t run on online IDE as no ‘privatekey’ Keystore exists. You can check this code on Java compiler on your system. To check this code, create a Keystore ‘privatekey’ on your system and set your own Keystore password to access that Keystore.
Below are the examples to illustrate the getCertificate() method:
Example 1:
// Java program to demonstrate getEntry() 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            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);              // creating and initializing            // KeyStore.ProtectionParameter object            KeyStore.ProtectionParameter entryPassword                = new KeyStore.PasswordProtection(pass);              // getting KeyStore.PrivateKeyEntry object            // using getEntry() method            KeyStore.PrivateKeyEntry print                = (KeyStore.PrivateKeyEntry)sr                      .getEntry("ftpkey", entryPassword);              // display the result            System.out.println("PrivateKey of particular entry: "                               + print.getPrivateKey());        }        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 (UnrecoverableEntryException e) {              System.out.println("Exception thrown : " + e);        }    }}
Example 2: For KeyStoreException
// Java program to demonstrate getEntry() 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            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);              // creating and initializing            // KeyStore.ProtectionParameter object            KeyStore.ProtectionParameter entryPassword                = new KeyStore.PasswordProtection(pass);              // getting KeyStore.PrivateKeyEntry object            // using getEntry() method            KeyStore.PrivateKeyEntry print                = (KeyStore.PrivateKeyEntry)sr                      .getEntry("ftpkey", entryPassword);              // display the result            System.out.println(                "PrivateKey of particular entry : "                + print.getPrivateKey());        }        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 (UnrecoverableEntryException e) {              System.out.println("Exception thrown : " + e);        }        catch (NoSuchAlgorithmException e) {              System.out.println("Exception thrown : " + e);        }    }}
Reference: https://docs.oracle.com/javase/9/docs/api/java/security/KeyStore.html#getEntry-java.lang.String-java.security.KeyStore.ProtectionParameter-
shubham_singh
singghakshay
Java-Functions
Java-KeyStore
Java-security package
Java
Java
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