java大文本读取（几个G的文本）

public class BigFileRead  {
    public static void main(String[] arg) {
        try {
            int bufSize=1024;
            byte[] bs = new byte[bufSize];
            ByteBuffer byteBuf = ByteBuffer.allocate(1024);
            FileChannel channel = new RandomAccessFile("D:\\DOC_bao\\hyip_app_user_request_old.log","r").getChannel();

            while(channel.read(byteBuf)!=-1){
            int size = byteBuf.position();
                byteBuf.rewind();
                byteBuf.get(bs);
                System.out.println(new String(bs,0,size,"GBK"));
                byteBuf.clear();
            }
        } catch (IOException e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        }
    }
}

//读取行（升级版）
    public static void main(String[] arg) {

        try {
            Date start = new Date();
            int count = 0;
            int countLoop = 0;
            String tailStr = "";
            int bufSize = 1024 * 1024 * 20;
//            int bufSize = 16;
            byte[] bs = new byte[bufSize];
            ByteBuffer byteBuf = ByteBuffer.allocate(bufSize);
//            FileChannel channel = new RandomAccessFile("D:\\DOC_bao\\hyip_app_user_request_old.log","r").getChannel();
            FileChannel channel = new RandomAccessFile("D:\\var\\log\\hyip\\hyip_app_user_request.log", "r").getChannel();
//            FileChannel channel = new RandomAccessFile("D:\\DOC_bao\\hyip_app_user_request.log.2013-06-20", "r").getChannel();
            while (channel.read(byteBuf) != -1) {
                countLoop++;
                int size = byteBuf.position();
                byteBuf.rewind();
                byteBuf.get(bs);
                String bufferStr = new String(bs, 0, size, "utf-8");

                if (bufferStr.indexOf("\n") >= 0) {
                    String[] b = bufferStr.split("\\n");
                    int len = b.length;

                    if (len > 0) {
                        b[0] = tailStr + b[0];
                        //如果最后一个是换行符，说明是整行，直接处理，否则放在临时变量里下次处理。
                        if (bufferStr.lastIndexOf("\n") == bufferStr.length() - 1) {
                            tailStr = "";
                            len++;
                        } else {
                            tailStr = b[len - 1];
                        }
                        for (int i = 0; i < len - 1; i++) {
                            count++;
//                          System.out.print(count + ":" + b[i]);
                            DBOperate(b[i]);
                        }
                    }
                } else { //如果一行数据过大，超过缓冲区，就追加到临时变量里。
                    tailStr += bufferStr;
                }
                byteBuf.clear();
            }

            if (tailStr != null && tailStr.length() > 0) {
                count++;
//                System.out.print(count + ":" + tailStr);
                DBOperate(tailStr);
            }

            Date end = new Date();
            System.out.println(start);
            System.out.println(end);
            Long spendTime =end.getTime() -start.getTime();
            System.out.println("spend time:"+spendTime+"");
            System.out.println(count);
//            System.out.println(countLoop);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }