package day01;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
/**
* 读写基本数据类型,以及raf指针的操作
* @author Administrator
*
*/
public class RandomAccessFileDemo6 {
public static void main(String[] args) throws IOException {
RandomAccessFile raf = new RandomAccessFile(
"raf.dat","rw");
//获取指针位置
long pos = raf.getFilePointer();
System.out.println("pos:"+pos);
//向文件中写入int最大值
int max = Integer.MAX_VALUE;
/*
* vvvvvvvv
* 01111111 11111111 11111111 11111111
* max>>>24
* 00000000 00000000 00000000 01111111
*/
raf.write(max>>>24);
System.out.println("pos:"+raf.getFilePointer());
/*
* RAF提供了方便我们写出基本类型的相关方法
*
*/
//一次性将给定的int值4字节全部写出
raf.writeInt(max);
System.out.println("pos:"+raf.getFilePointer());
raf.writeLong(123L);
System.out.println("pos:"+raf.getFilePointer());
raf.writeDouble(123.123);
System.out.println("pos:"+raf.getFilePointer());
/*
* void seek(long pos)
* 移动指针到指定位置。
*/
raf.seek(0);
System.out.println("pos:"+raf.getFilePointer());
//读取 EOF end of file
int d = raf.readInt();
System.out.println("long:"+1);
System.out.println("pos:"+raf.getFilePointer());
//读取long
raf.seek(8);
long l = raf.readLong();
System.out.println("long:"+1);
System.out.println("pos:"+raf.getFilePointer());
System.out.println("写出完毕");
raf.close();
}
}
Java——RandomAccessFile,读写基本数据类型,以及raf指针的操作
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转载自blog.csdn.net/weixin_43442290/article/details/88651866
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