Java中的IO流（六）

 1 public class Person implements Serializable {
 2     private static final long serialVersionUID = 1L;
 3     private String name;
 4     private static int age;
 5 
 6     public String getName() {
 7         return name;
 8     }
 9 
10     public void setName(String name) {
11         this.name = name;
12     }
13 
14     public int getAge() {
15         return age;
16     }
17 
18     public void setAge(int age) {
19         this.age = age;
20     }
21 
22 }

 1 public class Person implements Serializable {
 2     private static final long serialVersionUID = 1L;
 3     private transient String name;
 4     private static int age;
 5 
 6     public String getName() {
 7         return name;
 8     }
 9 
10     public void setName(String name) {
11         this.name = name;
12     }
13 
14     public int getAge() {
15         return age;
16     }
17 
18     public void setAge(int age) {
19         this.age = age;
20     }
21 
22 }

1     private static void function_demo3() throws IOException {
2         RandomAccessFile raf = new RandomAccessFile("raf.txt", "rw");//以读取写入方法创建文件(若文件不存在)
3         raf.write("sb".getBytes());//写入两个字节
4         raf.writeInt(97);//写入一个Int数据，此方法按四个字节写入文件，先写高位
5         raf.write("小龙".getBytes());//由于是utf8编码形式，所以两个汉字占用了六个字节
6         raf.writeInt(109);//写入四个字节
7         raf.close();8     }

 1     private static void function_demo4() throws IOException {
 2         RandomAccessFile raf = new RandomAccessFile("raf.txt", "r");
 3         byte[] bt = new byte[2];//因为存储时是两个字节，所以这里声明字节数组长度为2
 4         raf.read(bt);//从RandomAccessFile所维护的byte数组中读取前两个字节的内容
 5         System.out.println(new String(bt));//转为字符输出
 6         System.out.println(raf.readInt());//用readInt方法读取写入的int数据97
 7         byte[] be = new byte[6];//因为存储时两个汉字共6个字节，所以声明长度为6
 8         raf.read(be);//读取6个字节到be
 9         System.out.println(new String(be));//转成字符输出
10         System.out.println(raf.readInt());//读取109数据
11         raf.close();
12     }

 1     private static void function_demo5() throws IOException {
 2         RandomAccessFile raf = new RandomAccessFile("raf.txt", "rw");
 3         raf.seek(10);// 将RandomAccessFile维护的数组指针移动到下标为10的位置
 4         raf.write("李四".getBytes());// 写入六个字节
 5         System.out.println(raf.getFilePointer());// 获取当前指针的位置16
 6         raf.seek(10);// 将指针移动到10的位置，可直接读取到刚才写放的内容
 7         byte[] bt = new byte[3];
 8         int len;
 9         while ((len = raf.read(bt)) != -1) {
10             System.out.print(new String(bt) + "   ");
11         }
12         raf.close();
13     }