RefreshTokenDAO.java

package org.keycloak.example;

import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;

import org.keycloak.common.util.StreamUtil;

/**
 * Very simple DAO, which stores/loads just one token per whole application into file in tmp directory. Useful just for example purposes.
 * In real environment, token should be stored in database.
 *
 * @author <a href="mailto:mposolda@redhat.com">Marek Posolda</a>
 */
public class RefreshTokenDAO {

    public static final String FILE = System.getProperty("java.io.tmpdir") + "/offline-access-portal";

    public static void saveToken(final String token) throws IOException {
        PrintWriter writer = null;
        try {
            writer = new PrintWriter(new BufferedWriter(new FileWriter(FILE)));
            writer.print(token);
        } finally {
            if (writer != null) {
                writer.close();
            }
        }
    }

    public static String loadToken() throws IOException {
        FileInputStream fis = null;
        try {
            fis = new FileInputStream(FILE);
            return StreamUtil.readString(fis);
        } catch (FileNotFoundException fnfe) {
            return null;
        } finally {
            if (fis != null) {
                fis.close();
            }
        }
    }
}