/**
* Created by scott on 2019/7/19.
*/
public class test {
public static void main(String args[]) throws Exception {
int bufSize = 100;
File fin = new File("C:\\Users\\User\\Desktop\\localhost_access_log.2019-07-16.txt");
File fout = new File("C:\\Users\\User\\Desktop\\localhost_access_log.2019-07-16_AAAA.txt");
FileChannel fcin = new RandomAccessFile(fin, "r").getChannel();
ByteBuffer rBuffer = ByteBuffer.allocate(bufSize);
FileChannel fcout = new RandomAccessFile(fout, "rws").getChannel();
ByteBuffer wBuffer = ByteBuffer.allocateDirect(bufSize);
readFileByLine(bufSize, fcin, rBuffer, fcout, wBuffer);
System.out.print("OK!!!");
}
public static void readFileByLine(int bufSize, FileChannel fcin, ByteBuffer rBuffer, FileChannel fcout, ByteBuffer wBuffer) {
String enterStr = "\n";
try {
byte[] bs = new byte[bufSize];
StringBuffer strBuf = new StringBuffer("");
while (fcin.read(rBuffer) != -1) {
int rSize = rBuffer.position();
rBuffer.rewind();
rBuffer.get(bs);
rBuffer.clear();
String tempString = new String(bs, 0, rSize);
int fromIndex = 0;
int endIndex = 0;
//查找换行符符号\n，如果找到了，则写文件，如果没有找到则继续读取
while ((endIndex = tempString.indexOf(enterStr, fromIndex)) != -1) {
String line = tempString.substring(fromIndex, endIndex);
line = strBuf.toString() + line;
System.out.println(line);
;
if (line.contains("1111111111111111")) {
writeFileByLine(fcout, line + "\n");
}
strBuf.delete(0, strBuf.length());
fromIndex = endIndex + 1;
}
if (rSize > tempString.length()) {
strBuf.append(tempString.substring(fromIndex, tempString.length()));
} else {
strBuf.append(tempString.substring(fromIndex, rSize));
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
public static void writeFileByLine(FileChannel fcout, String line) {
try {
fcout.write(ByteBuffer.wrap(line.getBytes()), fcout.size());
} catch (IOException e) {
e.printStackTrace();
}
}
}
