java随机读取文件

package randomRead;import java.io.File;import java.io.FileNotFoundException;import java.io.IOException;import java.io.RandomAccessFile;//随机读取文件public class RandomTest {public static void main(String[] args) {RandomTest t = new RandomTest();File src = new File("d:\\holen.xml");File dest = new File("d:\\copy.txt");t.copy(src, dest, 0, 8);}public void copy(File src, File dest, int start, int end) {try {RandomAccessFile in = new RandomAccessFile(src, "r");  //读取文件RandomAccessFile out = new RandomAccessFile(dest, "rw");  //写文件int buf_size = 1024;byte[] buf = new byte[buf_size];int out_end = (int) out.length(); // 追加到文件结尾while (start < end) {int len = end - start;if (len > buf_size) {len = buf_size;}in.seek(start);  //指向源文件的开始位置in.read(buf, 0, len);  //把文件内容读入缓冲区out.seek(out_end); //指向目标文件的结束位置out.write(buf, 0, len); //把文件内容写入缓冲区start += len;out_end += len;}in.close();out.close();} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}}