Following are code examples for the GnuPG Java Wrapper API class.
Before you can use the class, you will need to create a private/public key pair in GPG. If you already set up the key pair, you can skip this step.
Launch the command line terminal and type the following:
gpg --gen-key
After answering these questions, GPG will create and store the key in its database.
We are now ready to use the Java API class with GPG.
import java.util.*;
import java.io.*;
import GnuPG;
// text to be signed
String text = 'GnuPG Java Wrapper API';
// PGP passphrase
String passPhrase = 'secret passphrase';
boolean result;
GnuPG pgp = new GnuPG ();
result = pgp.sign (text, passPhrase);
if (result)
{
System.out.println ("Result:\n" + pgp.gpg_result + "\n\n");
}
else
{
System.out.println ("Error signing:" + pgp.gpg_err + "\n\n");
}
import java.util.*;
import java.io.*;
import GnuPG;
// text to be clear signed
String text = 'GnuPG Java Wrapper API';
// PGP passphrase
String passPhrase = 'secret passphrase';
boolean result;
GnuPG pgp = new GnuPG ();
result = pgp.clearSign (text, passPhrase);
if (result)
{
System.out.println ("Result:\n" + pgp.gpg_result + "\n\n");
}
else
{
System.out.println ("Error clear signing:" + pgp.gpg_err + "\n\n");
}
import java.util.*;
import java.io.*;
import GnuPG;
// text to be signed and encrypted
String text = 'GnuPG Java Wrapper API';
//// The ID of PGP key (use gpg --list-keys to get the key ID)
String keyID = '8AC1';
// PGP passphrase
String passPhrase = 'secret passphrase';
boolean result;
GnuPG pgp = new GnuPG ();
result = pgp.signAndEncrypt (text, keyID, passPhrase);
if (result)
{
System.out.println ("Result:\n" + pgp.gpg_result + "\n\n");
}
else
{
System.out.println ("Error encrypting and signing:" + pgp.gpg_err + "\n\n");
}
import java.util.*;
import java.io.*;
import GnuPG;
// text to be encrypted
String text = 'GnuPG Java Wrapper API';
// The ID of PGP key (use gpg --list-keys to get the key ID)
String keyID = '8AC1';
boolean result;
GnuPG pgp = new GnuPG ();
result = pgp.encrypt (text, keyID);
if (result)
{
System.out.println ("Result:\n" + pgp.gpg_result + "\n\n");
}
else
{
System.out.println ("Error encrypting:" + pgp.gpg_err + "\n\n");
}
import java.util.*;
import java.io.*;
import GnuPG;
// text to be decrypted
String text = 'AB14CE281A6... 65A4F891';
// PGP passphrase
String passPhrase = 'secret passphrase';
boolean result;
GnuPG pgp = new GnuPG ();
result = pgp.decrypt (text, passPhrase);
if (result)
{
System.out.println ("Result:\n" + pgp.gpg_result + "\n\n");
}
else
{
System.out.println ("Error decrypting:" + pgp.gpg_err + "\n\n");
}