source: AE/installer2/src/net/oni2/aeinstaller/backend/oni/PersistDat.java@ 715

package net.oni2.aeinstaller.backend.oni;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.HashSet;

/**
 * @author Christian Illy
 */
public class PersistDat {
        private RandomAccessFile dat = null;

        /**
         * Open the given persist.dat
         * 
         * @param dat
         *            Path to persist.dat
         */
        public PersistDat(File dat) {
                try {
                        this.dat = new RandomAccessFile(dat, "rw");
                } catch (FileNotFoundException e) {
                        e.printStackTrace();
                }
        }

        /**
         * @return Currently unlocked levels in persist.dat
         */
        public HashSet<Integer> getUnlockedLevels() {
                HashSet<Integer> result = new HashSet<Integer>();
                if (dat != null) {
                        try {
                                dat.seek(8);
                                for (int i = 0; i < 32; i++) {
                                        int val = dat.read();
                                        for (int j = 0; j < 8; j++) {
                                                if ((val & (1 << j)) > 0) {
                                                        result.add(i * 8 + j);
                                                }
                                        }
                                }
                        } catch (IOException e) {
                                // TODO Auto-generated catch block
                                e.printStackTrace();
                        }
                }
                return result;
        }

        /**
         * @param unlock
         *            Levels to be unlocked in persist.dat
         */
        public void setUnlockedLevels(HashSet<Integer> unlock) {
                if (dat != null) {
                        if (unlock != null) {
                                try {
                                        dat.seek(8);
                                        for (int i = 0; i < 32; i++) {
                                                int val = 0;
                                                for (int j = 0; j < 8; j++) {
                                                        if (unlock.contains(i * 8 + j))
                                                                val |= 1 << j;
                                                }
                                                dat.write(val);
                                        }
                                } catch (IOException e) {
                                        // TODO Auto-generated catch block
                                        e.printStackTrace();
                                }
                        }
                }
        }

        /**
         * Close file
         */
        public void close() {
                if (dat != null) {
                        try {
                                dat.close();
                        } catch (IOException e) {
                                e.printStackTrace();
                        }
                }
        }
}