【每日日报】第三十五天

1 今天继续看书

打印流

 1 package File;
 2 import java.io.FileNotFoundException;
 3 import java.io.FileOutputStream;
 4 import java.io.PrintStream;
 5 
 6 public class PrintStreamDemo {
 7     public static void main(String[] args)throws FileNotFoundException{
 8         PrintStream out=new PrintStream(new FileOutputStream("D:/Hello.txt"));
 9         out.println(true);
10         out.println('A');
11         out.println(10.0);
12         out.println(12);
13         out.println("Hello");
14         Person p=new Person();
15         p.setAge(20);
16         p.setName("sky");
17         out.println(p);
18         out.close();
19     }
20 }

使用RandomAccessFile随机读写文件

 1 package File;
 2 import java.io.IOException;
 3 import java.io.RandomAccessFile;
 4 
 5 public class RandomAccessFileDemo {
 6     public static void main(String[] args)throws IOException{
 7     RandomAccessFile acf = new RandomAccessFile("D:/Hello.txt","rw");
 8     byte[] b=("Hello Java!!").getBytes();
 9     acf.write(b);
10     acf.seek(6);
11     System.out.println("pointre="+acf.getFilePointer());
12     byte[] b2="C++".getBytes();
13     acf.write(b2);
14     int len=-1;
15     byte[] buf=new byte[1024];
16     acf.seek(0);
17     System.out.println("pointer="+acf.getFilePointer());
18     while((len=acf.read(buf))!=-1){
19         String s=new String(buf,0,len);
20         System.out.println(s);
21     }
22   }
23 }

2 没遇到什么问题

3 明天继续看书写例题