import java.io.*;
public class RandomFileTest 
{
  public static void main(String [] args) throws Exception
  {
    Employee e1 = new Employee("zhangsan",23);
    Employee e2 = new Employee("lisi",22);
    Employee e3 = new Employee("wangwu",21);
    RandomAccessFile ra = new RandomAccessFile("c:\\1.txt","rw");
    ra.write(e1.name.getBytes());
    ra.writeInt(e1.age);
    ra.write(e2.name.getBytes());
    ra.writeInt(e2.age);
    ra.write(e3.name.getBytes());
    ra.writeInt(e3.age);
    ra.close();
    RandomAccessFile raf = new RandomAccessFile("c:\\1.txt","r");
    int len = 8;
    raf.skipBytes(12);  //跳过第一个员工的信息，其中姓名8字节，年龄4字节
    System.out.println("第二个员工信息:");
    String str = "";
    for(int i = 0;i < len;i++)
    {
      str = str + (char)raf.readByte();
    }
    System.out.println("name:" + str);
    System.out.println("age:" + raf.readInt());
    System.out.println("第一个员工信息:");
    raf.seek(0);  //将文件指针移到文件开始位置
    str = "";
    for(int i = 0;i < len;i++)
    {
      str = str + (char)raf.readByte();
    }
    System.out.println("name:" + str);
    System.out.println("age:" + raf.readInt());
    System.out.println("第三个员工信息:");
    raf.skipBytes(12);
    str = "";
    for(int i = 0;i < len;i++)
    {
      str = str + (char)raf.readByte();
    }
    System.out.println("name:" + str);
    System.out.println("age:" + raf.readInt());
    raf.close();
  }
}
class Employee
{
  String name;
  int age;
  final static int LEN = 8;
  public Employee(String name,int age)
  {
    if(name.length()>LEN)
    {
      name = name.substring(0,8);
    }
    else
    {
      while(name.length()<LEN)
        name = name +"\u0000";
    }
    this.name = name;
    this.age = age;
  }
}