文件内容操作九行

public RandomAccessFile(File file , String mode) throwsFileNotFoundException

public void close() throw IOException

public final byte readByte(byte[] b) throws IOException

public final int readInt() throws IOException

public final void writeByte(String s) throws IOException

public final void writeInt(int v) throws IOException

public int read(byte[] b) throws IOException

public void seek(long pos) throws IOException

public int skipBytes(int n) throws IOException