【每日日报】第三十二天

1 今天继续看书

DataOutputStream写文件

 1 package File;
 2 import java.io.IOException;
 3 import java.io.FileOutputStream;
 4 import java.io.DataOutputStream;
 5 import java.io.OutputStream;
 6 
 7 public class DataOutputStreamDemo {
 8     public static void main(String[] args)throws IOException{
 9         write();    
10     }
11     public static void write()throws IOException{
12         OutputStream os=new FileOutputStream("D:/Hello.txt");
13         DataOutputStream dos=new DataOutputStream(os);
14         dos.writeInt(123);
15         dos.writeBoolean(true);
16         dos.writeByte(34);
17         dos.writeBytes("Hello");
18         dos.writeChar(58);
19         dos.writeChars("java");
20         dos.writeDouble(20.0);
21         dos.writeFloat(20f);
22         dos.writeShort(31);
23         dos.writeUTF("C++");
24         dos.writeLong(13L);
25         dos.flush();
26         dos.close();
27     }
28 
29 }

DataInputStream读数据

 1 package File;
 2 import java.io.DataInputStream;
 3 import java.io.FileInputStream;
 4 import java.io.IOException;
 5 import java.io.InputStream;
 6 
 7 public class DataInputStreamDemo {
 8     public static void main(String[] args)throws IOException{
 9         read();
10     }
11     public static void read()throws IOException{
12         InputStream in =new FileInputStream("D:/Hello.txt");
13         DataInputStream dis =new DataInputStream(in);
14         int a=dis.readInt();
15         System.out.println(a);
16         System.out.println(dis.readBoolean());
17         System.out.println(dis.readByte());
18         System.out.println(dis.readChar());
19         System.out.println(dis.readDouble());
20         System.out.println(dis.readFloat());
21         System.out.println(dis.readFloat());
22         System.out.println(dis.readShort());
23         System.out.println(dis.readLong());
24         dis.close();
25         
26     }
27 
28 }

内存操作流

 1 package File;
 2 import java.io.IOException;
 3 import java.io.InputStream;
 4 import java.io.OutputStream;
 5 import java.io.ByteArrayInputStream;
 6 import java.io.ByteArrayOutputStream;
 7 
 8 public class ByteOutputStreamDemo {
 9     public static void main(String[] args)throws IOException{
10         outin();
11     }
12     public static void outin()throws IOException{
13         String info ="hello Java";
14         InputStream input=new ByteArrayInputStream(info.getBytes());
15         OutputStream output=new ByteArrayOutputStream();
16         int temp=0;
17         while((temp=input.read())!=-1){
18             output.write(Character.toUpperCase((char)temp));
19         }
20         String str =output.toString();
21         input.close();
22         output.close();
23         System.out.println(str);
24     }
25 
26 }

2 当用DataOutputStream写文件时，写出的文件会出现乱码

3 明天继续看书