java RandomAccessFile类文件基本操作

RandomAccessFile类是java中仿C的文件操作方法，下面通过实例演示RandomAccessFile类对文件的基本操作，深入了解请查看Java API文档。（注：RandomAccessFile类大多不被采用）

上代码

import java.io.*;

public class AccessFileDemo
{
	public static void main(String[] args)
	{
		Student stu1=new Student("Zhang San",10);
		Student stu2=new Student("Li Si",11);
		Student stu3=new Student("Wang Wu",12);

		try
		{
			//未找到文件时自动创建新文件
			RandomAccessFile af=new RandomAccessFile("F:\\workspace\\JavaPrj\\test.txt","rw");
			af.writeBytes(stu1.name);
			af.writeInt(stu1.age);
			af.writeBytes(stu2.name);
			af.writeInt(stu2.age);
			af.writeBytes(stu3.name);
			af.writeInt(stu3.age);
			af.close();

			af=new RandomAccessFile("F:\\workspace\\JavaPrj\\test.txt","r");
			System.out.println("The second person‘s information is");
			int len=8;
			String str=new String();
			af.skipBytes(12);
			while(len>0)
			{
				str=str+(char)af.readByte();
				len--;
			}
			System.out.println("Name: "+str);
			System.out.println("Age : "+af.readInt());

			System.out.println("The first person‘s information is");
			af.seek(0);
			len=8;
			str="";
			while(len>0)
			{
				str=str+(char)af.readByte();
				len--;
			}
			System.out.println("Name: "+str);
			System.out.println("Age : "+af.readInt());

			System.out.println("The third person‘s information is");
			af.skipBytes(12);
			len=8;
			str="";
			while(len>0)
			{
				str=str+(char)af.readByte();
				len--;
			}
			System.out.println("Name: "+str);
			System.out.println("Age : "+af.readInt());
		}
		catch (FileNotFoundException e)
		{
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		catch (IOException e)
		{
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

class Student
{
	String name;
	int age;

	Student(String str,int num)
	{
		if(str.length()>8)
		{
			str=str.substring(0, 8);	//从索引0到索引7的字符
		}
		else
		{
			while(str.length()<8)
			{
				str=str+"\u0000";
			}
		}
		name=str;
		age=num;
	}
}

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