关于java中流的使用--文件以及socket

个人感觉,流是java中不同设备之间交换数据的媒介,例如socket中数据的传输,以及文件的读写操作等,都是通过流来实现的.

流的种类

从处理的数据类型上来看,流主要分为字符流(InputStream, OutputStream)和字节流(Reader, Writer),而从功能上来看,主要分为输入流以及输出流.

文件的读写

1. File file =newFile(".\\test.txt");
2. //参数true:表示在文件后边追加内容
3. FileOutputStream fileOutputStream =newFileOutputStream(file,true);
4. FileInputStream fileInputStream =newFileInputStream(file);
5. //装饰者模式,使用带缓冲的输入流
6. BufferedInputStream bufferedInputStream =newBufferedInputStream(fileInputStream);
7. //使用byte,字节流读取文件中的内容
8. byte[]b =newbyte[100];
9. bufferedInputStream.read(b);
10. Stringstring=newString(b,"UTF-8");
11. System.out.println(string);
12. //使用字符流读取文件中的内容
13. BufferedReader bufferedReader =newBufferedReader(inputStreamReader);
14. System.out.println(bufferedReader.readLine());
17. //写入文件
18. OutputStreamWriter outputStreamWriter =newOutputStreamWriter(fileOutputStream);
19. outputStreamWriter.write("jjjjjjjjjjjjjjjjjjjd我们哈哈哈哈哈");
20. BufferedOutputStream bufferedOutputStream =newBufferedOutputStream(fileOutputStream);
21. bufferedOutputStream.flush();
22. Stringstring="我们进顶顶顶顶顶顶顶顶顶大大大";
23. byte[]b =string.getBytes("UTF8");
24. bufferedOutputStream.write(b);
25. bufferedOutputStream.close();

socket使用

Server

1. publicclassTcpServer{
2. publicstaticvoid main(String[] args)throwsIOException{
3. // TODO Auto-generated method stub
4. String getString;
5. String sendString;
6. ServerSocket socket =newServerSocket(6789);
7. while(true){
8. Socket connection = socket.accept();
9. BufferedReader reader =newBufferedReader(newInputStreamReader(connection.getInputStream()));
10. DataOutputStream outputStream =newDataOutputStream(connection.getOutputStream());
11. getString = reader.readLine();
12. sendString = getString.toUpperCase()+"\n";
13. outputStream.writeBytes(sendString);
14. }
15. }
16. }

Client

1. publicclassTcpClient{
2. publicstaticvoid main(String[] args)throwsUnknownHostException,IOException{
3. String sendString;
4. String getString;
5. System.out.println("start connection");
6. Socket socket =newSocket("127.0.0.1",6789);
7. System.out.println("connect successfully");
8. DataOutputStream outputStream =newDataOutputStream(socket.getOutputStream());
9. BufferedReader fromServer =newBufferedReader(newInputStreamReader(socket.getInputStream()));
10. sendString ="send to server from tcpclient";
11. outputStream.writeBytes(sendString +"\n");
12. getString = fromServer.readLine();
13. InputStreamin= socket.getInputStream();
14. byte[] b =newbyte[100];
15. in.read(b);
16. Stringstring=newString(b,"UTF-8");
17. System.out.println(b);
18. socket.close();
19. }
20. }

来自为知笔记(Wiz)