Person中有name和age属性，要求存储若干个Person对象到磁盘中， 使用 RandomAccessFile流来实现

package Rand;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.RandomAccessFile;

import java.util.ArrayList;

import java.util.List;

import java.util.Scanner;

/**

*

* 要求:Person中有name和age属性，要求存储若干个Person对象到磁盘中， 使用 RandomAccessFile流来实现

*

*/

public class RandomAccessFileDemo {

public static void main(String[] args) {
System.out.println("start...");
List<Person> list = new ArrayList<Person>();
list.add(new Person("张三", 21));
list.add(new Person("李四", 22));
list.add(new Person("王五", 23));
list.add(new Person("小计", 24));
list.add(new Person("小菜次", 25));
try {
RandomAccessFile raf = new RandomAccessFile("e:\\aaa.txt", "rw");
for (Person person : list) {
raf.writeChars(person.getName());
raf.writeInt(person.getAge());

}
System.out.println("请输入要显示第几个人的信息：");
Scanner scanner = new Scanner(System.in);
int n = scanner.nextInt();

int index = Person.TOTAL_SIZE * (n - 1);
raf.seek(index);
String name = getChars(raf);
int age = raf.readInt();
System.out.println("姓名:" + name);
System.out.println("年龄:" + age);
raf.close();

} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("end...");
}

private static String getChars(RandomAccessFile raf) throws IOException {

StringBuilder sb = new StringBuilder();
for (int i = 0; i < Person.NAME_SIZE; i++) {
sb.append(raf.readChar());
}
return sb.toString();
}

}

class Person {

private String name;

private int age;

public static final int NAME_SIZE = 15;
public static final int TOTAL_SIZE = 15 * 2 + 4;

public Person(String name, int age) {
super();
setName(name);
this.age = age;

}

public String getName() {
return name;

}

public void setName(String name) {

StringBuilder sb = new StringBuilder(name != null ? name : "");
sb.setLength(NAME_SIZE);
this.name = sb.toString();

}

public int getAge() {
return age;

}

public void setAge(int age) {
this.age = age;
}

public String toString() {
return "Person [name = " + name + ",age=" + age + "]";

}

}