1 import java.io.BufferedReader;
2 import java.io.File;
3 import java.io.FileInputStream;
4 import java.io.IOException;
5 import java.io.RandomAccessFile;
6 import java.nio.ByteBuffer;
7 import java.nio.channels.FileChannel;
8
9 public class TestNio {
10
11
12 public static void main(String args[]) throws Exception{
13
14 //String infile = "D:\\workspace\\test\\usagetracking.log";
15 //FileInputStream fin= new FileInputStream(infile);
16 //FileChannel fcin = fin.getChannel();
17
18 int bufSize = 100;
19 File fin = new File("D:\\workspace\\test\\usagetracking.log");
20 File fout = new File("D:\\workspace\\test\\usagetracking2.log");
21
22 FileChannel fcin = new RandomAccessFile(fin, "r").getChannel();
23 ByteBuffer rBuffer = ByteBuffer.allocate(bufSize);
24
25 FileChannel fcout = new RandomAccessFile(fout, "rws").getChannel();
26 ByteBuffer wBuffer = ByteBuffer.allocateDirect(bufSize);
27
28
29 readFileByLine(bufSize, fcin, rBuffer, fcout, wBuffer);
30
31 System.out.print("OK!!!");
32 }
33
34 public static void readFileByLine(int bufSize, FileChannel fcin, ByteBuffer rBuffer, FileChannel fcout, ByteBuffer wBuffer){
35 String enterStr = "\n";
36 try{
37 byte[] bs = new byte[bufSize];
38
39 int size = 0;
40 StringBuffer strBuf = new StringBuffer("");
41 //while((size = fcin.read(buffer)) != -1){
42 while(fcin.read(rBuffer) != -1){
43 int rSize = rBuffer.position();
44 rBuffer.rewind();
45 rBuffer.get(bs);
46 rBuffer.clear();
47 String tempString = new String(bs, 0, rSize);
48 //System.out.print(tempString);
49 //System.out.print("<200>");
50
51 int fromIndex = 0;
52 int endIndex = 0;
53 while((endIndex = tempString.indexOf(enterStr, fromIndex)) != -1){
54 String line = tempString.substring(fromIndex, endIndex);
55 line = new String(strBuf.toString() + line);
56 //System.out.print(line);
57 //System.out.print("</over/>");
58 //write to anthone file
59 writeFileByLine(fcout, wBuffer, line);
60
61
62 strBuf.delete(0, strBuf.length());
63 fromIndex = endIndex + 1;
64 }
65 if(rSize > tempString.length()){
66 strBuf.append(tempString.substring(fromIndex, tempString.length()));
67 }else{
68 strBuf.append(tempString.substring(fromIndex, rSize));
69 }
70 }
71 } catch (IOException e) {
72 // TODO Auto-generated catch block
73 e.printStackTrace();
74 }
75 }
76
77 public static void writeFileByLine(FileChannel fcout, ByteBuffer wBuffer, String line){
78 try {
79 //write on file head
80 //fcout.write(wBuffer.wrap(line.getBytes()));
81 //wirte append file on foot
82 fcout.write(wBuffer.wrap(line.getBytes()), fcout.size());
83
84 } catch (IOException e) {
85 // TODO Auto-generated catch block
86 e.printStackTrace();
87 }
88 }
89
90 }
