java读取txt文件,该如何处理

package to.shin.sai;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.OutputStreamWriter;import java.io.PrintWriter;import java.io.RandomAccessFile;public class Test4ReadLargeFile {    private final long LAST_LINE_COUNT = 10;    private final long MAX_LINE_COUNT = 400;    private final int MAX_THREAD_COUNT = 5;    private String[][] resArr = null;    private boolean[] finished = null;    private String fileEncode = "";    Object lock = new Object();    /**     * @param args     */    public static void main(String[] args) {        String filePath = "c:\\largeFile.txt";        Test4ReadLargeFile trlf = new Test4ReadLargeFile();        trlf.read(filePath, "SJIS");    }    public void read(String filePath, String charset) {        long beginTime = System.currentTimeMillis();        System.out.println("开始时间：" + beginTime);        this.fileEncode = charset;        RandomAccessFile raf = null;        try {            raf = new RandomAccessFile(filePath, "r");            long fileSize = raf.length();            long beginPos = (MAX_LINE_COUNT - LAST_LINE_COUNT) * fileSize / MAX_LINE_COUNT;            long length = fileSize - beginPos;            long perLength = length / MAX_THREAD_COUNT;            resArr = new String[MAX_THREAD_COUNT][];            finished = new boolean[MAX_THREAD_COUNT];            for (int i = 0; i < MAX_THREAD_COUNT; i++) {                new ReadFileThread(beginPos + i * perLength, Math.min(beginPos + (i + 1)                        * perLength, fileSize - 1), filePath, i).start();            }        } catch (FileNotFoundException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        } catch (Exception e) {            e.printStackTrace();        } finally {            if (null != raf)                try {                    raf.close();                } catch (IOException ioe) {                }        }        //等待结束        synchronized (lock) {            try {                lock.wait();            } catch (InterruptedException e) {            }        }        long endTime = System.currentTimeMillis();        System.out.println("结束时间：" + endTime);        System.out.println("耗时：" + (endTime - beginTime) + "ms");    }    class ReadFileThread extends Thread {        // the begin position        private long beginPos = 0L;        // the end position        private long endPos = 0L;        // the current position        private long curPos = 0L;        // the file        private RandomAccessFile raf = null;        private int resIndex = 0;        public ReadFileThread(long beginPos, long endPos, String filePath, int resIndex)                throws Exception {            super("ReadFileThread: " + resIndex);            if (endPos - beginPos > Integer.MAX_VALUE)                throw new Exception("It's too large size to read for this job");            this.beginPos = beginPos;            this.endPos = endPos;            this.resIndex = resIndex;            raf = new RandomAccessFile(filePath, "r");            raf.seek(beginPos);        }        private boolean checkRun() {            try {                // 起点和终点在同一行的话，不需要读                raf.seek(beginPos);                raf.readLine();                long beginLine = raf.getFilePointer();                raf.seek(endPos);                raf.readLine();                long endLine = raf.getFilePointer();                raf.seek(beginPos);                if (beginLine == endLine)                    return false;            } catch (Exception e) {                e.printStackTrace();            }            return true;        }        @Override        public void run() {            if (!checkRun())                return;            try {                // skip the first line                raf.readLine();                curPos = raf.getFilePointer();                byte[] content = new byte[(int) (endPos - curPos + 1)];                int offset = 0;                while (curPos + offset <= endPos) {                    offset += raf.read(content, offset, (int) (content.length - offset));                }                byte[] res = content;                // 读取最后一行                byte[] lastBytes = new byte[1024];                raf.read(lastBytes);                int returnKeyIndex = 0;                // 假设最后一行最大不超过1K，如果考虑全，还要写完整（我懒）                for (int i = 0; i < lastBytes.length; i++) {                    if (lastBytes[i] == 10 || lastBytes[i] == 13) {                        returnKeyIndex = i;                        break;                    }                }                res = new byte[offset + returnKeyIndex];                System.arraycopy(content, 0, res, 0, offset);                System.arraycopy(lastBytes, 0, res, offset, returnKeyIndex);                String resStr = new String(res, fileEncode);                resStr = resStr.replaceAll("\r", "");                resArr[resIndex] = resStr.split("\n");                noticeFinished(resIndex);            } catch (Exception e) {                e.printStackTrace();            } finally {                if (null != raf)                    try {                        raf.close();                    } catch (IOException ioe) {                    }            }            super.run();        }    }    private void noticeFinished(int index) {        finished[index] = true;        System.out.println("Thread " + index + " is over.");        for (boolean f : finished)            if (!f)                return;        synchronized (lock) {            lock.notify();        }        finish();        System.out.println("all data is readed");    }    private void finish() {        PrintWriter pw = null;        try {            pw = new PrintWriter(new OutputStreamWriter(new FileOutputStream("c:\\result.txt"),                    fileEncode));            for (int i = 0; i < resArr.length; i++)                if (null != resArr[i])                    for (int j = 0; j < resArr[i].length; j++) {                        pw.println(resArr[i][j]);                    }        } catch (Exception e) {            e.printStackTrace();        } finally {            if (null != pw)                try {                    pw.close();                } catch (Exception ioe) {                }        }    }}